welcome to the
rafter 5:10 remaining reflector for
2015 and I have some
housekeeping you should
switch up your mobile phones better
is no planned for evacuations tonight so if the bell rings
we've got to get out you should go that way amber
and the way you came in and the
event is being webcast I'm recorded so I think that means for
Jeff I'm for me gonna stand
nervous thing saw
this Lavenham Pletcher
is given every three years now am
to recognize excellence in microbiology
or microscopy or both and it's named for
Anthony Brown moment ok who was
a fellow no I'm pretty Royal Society
elected in 1690 I mean
essentially with his microscope discovered
bacteria that's the reason for concern
for name in the lecture for him it's its
the lecture itself is supported by the
este tema mom called George gab George gab was not
in there are thirty were mad scientist and chemist and
use an aunt
a
%uh Irish andrew is a pharmacist
remove her concern about and here
whom antiquarian I'm a collector and
he bequeathed also home a
action all leave until to bring society
all the things he did for the society Witcher
made his name a bit 130 am
was shown a portraying term Joseph priestly
and which had been the crew to the society and declared it a forgery
veterans claim to fame is real claim to fame is that the supports this lecture
their average three years now so
tonight's lecture is professor
Jer earned from who graduated in
Newcastle manganese Bhd in London
and then went to Oxford where he eventually became professor of
microbiology
any a move back to Newcastle
in 2010 6 to
become the Director love the Institute for cell and molecular
Biosciences and he's now the director of the center for bacterial
cell biology Jess researches on the mechanisms involved in cell division and
cell wall
formation and their interactions and in recent years he started
cell mutants lost the ability to make cell walls
I'm sure the importance of these studies will be
our future his lecture tonight on bacterial cell walls
antibiotics and the origins of life
it's mine great pleasure to introduce
and Jeff Arrington to give the
1915 lame not lecture
the that
thank you very much on flights and the kind introduction that kind
an introduction to me and also thanks very much to the Society for this
wonderful
accolade and finally I should thank Newcastle University because the
invested a lot in Los and they saw the potential AFP actual cell biology
and another will come get me talking about to you tonight was done in this
traffic building we're very proud of called the send him back to russel
version castle
so am the the lectures gonna be structured
like this I'm gonna I'm gonna give you a brief introduction to to microbiology
starting with with ok
and I'm not gonna tell you buy back chills structure
and I am and particularly focus on the importance of the cell wall
am its one of the reasons why it's really important is that it's a it's a
fantastic target for antibiotics and so I'll tell you a little bit about how how
I about exact on the cell wall work and then as john mentioned I'm gonna
sought to spend middle above technical stuff toward the end to the lecture in
which I'll tell you this but some by recent research
that little bit perversely has been looking at cell
bacterial cells that have no cell wall and is called alphonse
and Anna and about some other really amazing properties and at the
that the and I'll talk about the implications for the origins of life and
you'll see how
origins of life came into the research I'm that we've been doing
as a result of this work on on all forms so
I i want to begin really by stating something pretty obvious some bacteria
extremely small and I was looking broke ground for
something to scale them them against and I i
found that the two pound coin is very suitable and then I realized it the 1997
version of this
I was actually very special its dedicated fools mutant realizes night I
didn't
its it's special because a dedicated to the I'm
tunes to scientific discovery and
on the on the action this is this little quote from from
which came from Isaac Newton which is very special to make the father of
society
what Newton said was if i've seen. fair though it's by standing on the shoulders
of giants
suffering very proper to use that and
and conveniently that this to find congress' is almost
exact
2,000 times wider than than a typical human soul she see
you see here and so that means that you could fit about
about him the best part a million human cells on the surface in the two-point
from quite so to insult or a small but then if you if you actually gonna
bacterial cell miss ames
in the same slide you'll still see the bacteria even smaller much smaller than
human cells
and and you could probably fit several thousand of these bacterial cells
into one human cell so this is about as good as it gets using light microscopy
you you receive a real very little the terms of actual structure from
I'm from light microscopy unita got its things like electron microscopy which I
mention later
and to to really blow the cells up not modified mention
again just to illustrate the the problem that we're up against looking a
bacterial cells
is dirt sand if you were to place appoint
green light within the cell and like this
point directly I'm because wait we're actually very close to the wavelength of
light
so this is this is the wavelength a green light on a similar kind of scale
what you actually sees a fuzzy blob light using like Mike want my part
prosecution before the properties at the light
so that means that the resolution actual structure by light microscopy very
challenging
but as out hope that convince the way what we're learning
a lot about the the ultrastructure bacterial cells and now
through this but you also biology am hatfield
so we have to begin with Anthony's of an event occurs John
John mention he's really the father microbiology he was the first person to
see to realize that they won't
microscopic am animals if you like old organisms
and these this is one of his microscope sisters tiny microscopic contrast that
with some the microscope that we use man soon
and and these are some illustrations that need to be put into some the
letters that he sent to the wrong society
and I compiled decide that will recognize that the major morphological
class is a bacteria
there basically to on maybe three morphologically distinct classes
there are ron shipp things like this there are sparkle things like these
these tiny
am things that we will call cock I there are few little things
and what are the other things that he knows which was amazing as any notice
the battery can actually swim so this style is actually moving
am and and in fact a consumer-directed mana and I'll show you
little bit later wanna
proteins that's involved in actually detecting chemical gradients and
directed which sells used it to
direct their test winning so
act actually read remarkably little happened if you look at the history
microbiology over the next two hundred years
and it was it was really numb to let the end of the 19th century
that time microbiologists really connected infectious disease to
particular kinds of bacteria
and mother wanna be here isn't this period was Hans Christian brown
am and towards the end of the 19th century he invented the sustaining
method called tackle the Gram stain
which is actually stick it's a such a fantastic stain that it still use to
this day
by clinical microbiologist and so if there are
so that distinguishes between gram-positive bacteria which which a
blue
a purple and run negative bacteria which through the stain actually appear
think I'm and this is important because it turns out and brown couldn't possibly
have known this
that the the difference in Gram staining is actually to do with the
the structure at the cell surface which is different in gram-positive bacteria
from gram-negative bacteria and these organisms the gram-positive and
gram-negative probably diverged from each other
am something like a billion years ago so it's it's a very important distinction
which which promise covered and which is still used and soak again
you week we can see I'm two different kinds much here we can see their shapes
but really
that was all we had to go on with in terms of microbial structure for
for many and many decades now in the middle
the last century the the from a resolution was resolved by the advent
back to microscopy and so this is a
the modern typical action like microscope from
from Newcastle and basically as an electron gun here
there's a specimen chamber here the electrons a fight at the specimen
and then images collected at the bottom of the machine here it can be displayed
nowadays on
on a computer display and the solve the resolution problem
but its at a cost and the cost comes
from the fact that electrons are very easily scattered and be my water
molecules
and so to get good images through a fam its biological specimens with
by electron microscopy you have to dehydrate them you have to take the
Water Act
and and you have to do with several other things for example have to fix the
cells with
with horrible
chemicals that make possible coming across links to stop them to being
destroyed when you dehydrate them and then
afterwards after embed them in plastic than you have to
section with a diamond knife to get sections were just enough to be able to
be
visualized by electron microscopy and finally
these the specimens are actually relatively transparent and so you need
to spend them
and typically used in with something like uranium and very heavy heavy metal
atoms
it's time to to actually be able to resolve these beasts
art want to see anything in the stand these specimens some
when you do love this and am so that there are a lot of potential products
here
and what you can see are really basically four distinct structures
there's a sort a fluffy white stuff in the middle which is where the DNA is
there's a granular material called the cytoplasm which has many
write the songs and the protein synthetic apparatus than this is very
prominent cell wall structure on the outside
I'm just inside that is a some membrane which is very very visible
here this is a semi-permeable membrane which separates the inside the cell from
from from the outside
so am this this gave the impression overall the featureless kinda cell
structure
and a nap stayed with them microbiologists or biologist really for
several decades a given pressure simplicity in like a
compartmentalize ational regional specialization which i think is really
held feedback
feel back until recently so on this change in the 1990s and
Russia chan was one of the heroes of this he won the nobel prize with his
colleagues
followed for to realizing the potential
of taking protein from prevents me from a jellyfish
this that this kinda kinda jellyfish a reporter
am and this these are wonderful creatures if you go to the tropics
tropics and look in the seed
at night you can see these jellyfish glowing and so they generate their own
light
and one of the proteins that they use a general light as
is this political green fluorescent protein and what shannon is Cali
colleagues
did was to harness this is a tool for actually
and imaging also two things in biological systems
so in bacteria what we do is we take we take a gene which is interesting to us
which might be involved in cell wall synthesis all
down television and we use genetic engineering methods
to take that good the gene which can reach me from the jellyfish
and actually fuse ated aren't enough interest what then happens is that this
generates a hybrid approach in which which
which hopefully is functional which which is produced
with the same as the protein which is made by a dream interest except that it
has a screen type on it
and this gives a start pinpointing green light am
which I mentioned in the release slide which enables us
dusted to followed using am
modern for essence microscopes where this protein
goes inside the cell and so we can do this to all the proteins bacterial cells
are being asked where did they go
in the cell so this is this is
in contrast ill non-living hooks I'm early microscope
this is a this is one of the microscope so we have now in the CBC Byetta
commercial microscope and what's amazing about the
the way this technology is developing now is that these microscopes are
starting to
to overcome the summer the limitations
of light microscopy due to the wavelength the flight
and so this this gives us something like a two fold improvement in resolution
over the best presence microscopes that that used to be available
am and and you see the complexity of the system it said his microscope but then
they release a lot on the lasers and
cameras and then the whole thing gets get Sky connected to a computer which
collects the
digital images in I'm work with him is a process
suffered in the next few slides out shall show you some examples of what
we've been able to do
what we and many other labs have been able to do and in terms have
I'm honest antibacterial ultrastructure and so these are some people my lab who
who
2011 proteins and then got me some images to to look at
so many to put the lights down low because for the next few slight
so this is a very simple experiment here with him if taken
this green fluorescent protein and we fucked it up to a.m.
protein sequence that takes it to the membrane so this basically stains the
membrane
cell so you can see this beautiful green outline have these be subtilis
cells and you also see that in some urban there
they're actually initiating a a division the television event
which will eventually to the permissions to cells this one's just about completed
division so that so there are now two cells am and you see
the cells are in different stages have division so this is this is Sam
overly simple what we've done in in the next few slices to
replace that member in staying with the an actual red
died which stains the membrane and so we can see the outline of the so much as
much as he saw in the previous life
but then we've we've connected to the green fluorescent protein up to
a series a different cellular proteins so this example we've we've connected
the
to approaching college PSU which is what you might call a promise some organizing
protein
so this protein basically binds to the chromosome in the cell
DNA material and ban it did look
it localizes all over the promise someone so what you see is the outline
of
the chromosome in in the cells and what's interesting about these images is
that
you see his very often by lobed structures so there there are two blocks
of green
the connected together in each of these the cells we think these are chromosomes
in the process of being
being replicated am need and ultimately these days to blog serve
I've been will resolve and then the cell will divide in the middle to produce the
two
to ourselves kitchen which has a copy of the anti-communism from some
so this is a another DNA binding
protein but this one is are much more specific
it it localizes one very precise place on the chromosome
which colour or EC and this is the place where the replication of the back chill
chromosome
initiates and all those initiated the same single site and by chill
chromosomes
and so these green spots that you see here
actually corresponds to initiation am
initiation sites of on on the chromosome and if you count the spots
and inside their the the cells and you can see that the South has four
spot the sauce four spots in this one as eight
spot and what this tells you this kind of experiment owns he was a back Gerard
actually menacingly
am able to ambery initiate a round of DNA replication before the previous
round is even
finished so that can kinda got ahead of the game and
I'm not want 10 Jan will will will
alternative to origins non-issue those two origins will turn into I'm another
georgians giving you total four
and the seller's able to kinda balkanize X chromosome
with these multiple ongoing runs a replication and somehow managed to get
stopped everything from going completely tangled
and so that when the cell eventually divides and Paul
you know it you to the cells will will I'm obtaining from some company so
here's another kind of proteinase
brings us back to back find a mention very read the beginning about the
bacteria being able to direct the swimming so this is it
approaching colicky Marie scepter is effectively bacterial knowles
so this is approaching the connection detect cummick chemical gradients
and what you see with this protein tack to GFP is that the protein
is directed to the south poles and you get his little spots and localization
to sponsor localization often and each of the south poles
so this is where the bacterial noses these proteins help the
help the organism to to figure actor I'm and
to recognize chemical gradients and to respond to them so that they can swim
and banana for every direction so
so now we're going to some proteins that Sam with will feature later in the talk
and so this is one of my favorite proteins called
FTS said and so this this is basically in a master regulator
of cell division and its present in virtually all bacteria so this is the
protein that organizes the division machine
and enables bacterial cells in general to to divide
and so at this level a resolution and the FDA said
and protein has a very interesting look wise ish in part in
in in the east images am we're actually looking at it effectively a
cross-section through the cell
and you'll see that there are four cells here and they're actually in different
stages have
division this the cell has an incipient
division ongoing this one's just starting to divide
and these two cells are
kind even the stages of I'm not having initiated division yet but they've
already localize the
the division machines such as I protein at the right side
and when you see if you're sure if you shop I pass and sitting in the front is
that the
been every cell there are two spots left yes said that's because this is a ring
structure
and you're looking you looking down through the rain and seeing the 22 spots
the represent the side to the the Rings
and what what you you should be able to see is it
there the Rings you're a very widely spaced the rafters are proteins right at
the periphery of the cell
where the news 2008 dividing the green spots were closer together
and not tell you that the FBI said stays at the leading edge in the Sept as
as the division machine we actually constricts so you can actually follow
division in real time
by labeling proteins like this so yes
another of my favorite protein so I'm putting Colin Montgomerie be
it's a this is now a mosque deregulation regulator of cell shape
and it has yet it get a different localization pattern
this protein mix long filaments that
that are often the BP idk if he local and which wrap themselves around
the the long axis at the cell and this this protein
is the black one of the key proteins that determines the shape with the cell
and so these cells are run shaped and and most wretched bacteria
actually acquire back shape through the action of this
this family of proteins Emery the Trojans and ask for those who are
interested in cytoskeleton this is this is a
structural homologue of them human actin
filaments which am which are important so shape a new products also himself
so this this protein damn right it's %uh from front along axons the south and
actually controls the
way that the sole machinery synthesizers new material okay and then finally
I've searched for one slide from diesel is to E-coli
and that's because does another have
class is really amazing proteins in bacteria but actually
can ship deposition on a on a remarkable time scale so this is a min D Pro scene
and it's involved in determining
the location weather division site is placed in
in many bacteria
an N E coli it does this remarkable oscillation
CC this the protein starts in the middle then it goes to the
outside polling goes back to the Middle and back to the outside pole
and back again and so does this oscillation on a
with a period of something like fifty seconds and really remarkable
behavior lot of people physicists mathematicians are interested in trying
to understand how this works
and but basically what this protein does through this isolation
is figure out where the midpoint of the sallies and
minutes one other proteins that's really important in positioning on FB as a
dream that I mentioned earlier
am right in the middle of the cell you I will be noticed in those are the cells
lettering is always right in the middle
so they're out there are very sophisticated mechanisms that are
involved
and positioning and is entering in the middle and this is this is one of them
at least which is used by some bacteria so that's that's kind of an introduction
to
when we've gone with microscopy from from the very early crude
and light microscopy through to I'm absolutely
and modern up-to-date hams russians
microscopy with super-resolution am images
so what I'm in a text when mister the slides is just where
why when my particular research interests have been time for a number of
years
and not as many in this question discussions but I'll shipping about the
cell division cycle
and the the reason why I think this is really
really amazing as shown if you look at some but I'm not so much
of and my favorite organism Bacillus subtilis undergoing
growth and division so this is great be speeded up of course but
these T cells are going through a complete cell cycle in about 20 minutes
and so this is the whole series are probably 10 tennis 0
hassle cycles but if you look carefully these these images what what you'll see
is that the cells are incredibly
precise in the way they undergo division they basically
elongate they maintain a comp constant diameter
the you engage and when there's more less doubled in length they divide right
in the middle to produce to
baby cells the two baby cells both too baby so thank group
and Dublin links and then divide in the middle and to do this
over and over and over with incredibly high fidelity
and it's very rare to see a cell make a mistake in
in division in these time to time matter so how can the cell
organize its chromosome its growth
I'm its division am so that every single molecule not been that big newborn cell
is completely duplicated 20 minutes placer and that the two
too baby cells along on generated so it's an amazingly complicated
and biological problem but one which is a course I'm
really really fascinating so
the the bacterial cell wall turns out to be a key player in both both
I'm and division perhaps not surprising so what is the cell wall
well am in a sense it's a tough stretchy fabric to come as the whole-cell
cell surface what one another knowledge I like to use this time
that kinda spring rest so am
what one is the the reasons why you need the Spring Fest on
on the outside here is that I'm
you as you can see the cell cytoplasm is very concentrated
there what's not two molecules inside and whereas outside
medium is very diluted and closer view
you did the animal biology you realize that there's not a problem
because what the water outside he wants to rush in and equilibrium with the
high concentration of stuff in inside so that generates a very hyper
high-pressure
toga pressure pushing out on the membrane and the only reason this was a
licence walloping burst
it's because it has a string vest covering cell surface which will
constrain
its its growth so the solo hospital rules
in both cell growth and division and
and if you if you much in no going back. the Knology what the song needs to do is
to introduce
and news pictures into the into the vast so that it connects
extended and then when it's doubled in length acid N
divide the Spring Fest into two identical copies I'm
all the time retaining that this very
I'm hair highly-charged cytoplasm
and intact
so the wall turns out to be the crucial target for
for a best anti biotics penicillin covers for ins
and vancomycin hampered by you though damn
antibiotics that are still the foremost
term weapons that we have in common infectious disease actually were
consoles and sis
and the soul was also recognized by our innate immune system someone's
cells actual cells died 8 their release fragments at the cell wall
and our innate immune system to recognize those fragments and respond
appropriately
and to the to the try to infection the Wallace
has a very wide distribution so its it's thought that it was probably present in
the last common ancestor will bacteria so all major lineages a bacteria
have a stamp more or less the same cell wall structure so that suggest that the
very first
bacterial cell on the planet probably already had
as the cell wall to welcome back to the end as well because what happened before
that cell wall
was actually invented so
northern ayatollah from the biotechs it's essential for growth and viability
and this is in turn was more depression which is very dangerous
if wall integrity is is reached not show is in an image
and importantly there's no equivalent to the Selwyn
in humans we have no not about assaults have cell walls and that means we can
get selective toxicity
began get chemical compounds that will in dip down
chemical compounds which interfere with cell wall integrity will kill the
bacterial cell
but we've don't have to worry about any effect on human cells
so we can go back to killing the patient am
and so these are still a mess on the politics and but there is
I think the potential for new classes of antibiotics till
am talking on cell wall synthesis because there are still many elements
are so well since this
for which there are no clinically useful antibiotics right
right now so this this next movie is from
am my old my friend and colleague from I'm can can go to sam
who developed this Sat movie I think for a BBC
documentary about a year ago and what it shows he was a
time-lapse image a few coli cells on on the right as
on the control cells which you'll see a growing very nicely
and on the left ourselves that a sitting on a on a bed it's been impregnated with
penicillin
outputs and
so I T C T cells grow
go very nicely am just does that be some last time I so should you put on the
left wing si
that does all kinds of devastation occurring am
and the cells are a basically popping am
I think we'll run that one what one more time cuz I'm this idea of mass
destruction a bacterial cells i think is something that
most people and would like to see happening am
soon that's thrombotic
when they can thing seem to think it towards the end of the the movies this
assault on him russia's this beautiful exploding event
I think it's this one so there's a breach in the cell wall and then
basically the sold contents to simply explode from from from the sound that's
because it just took a pressure and
miniatures how how important the structures have actual cell
so and we've been entrusted for a long time now and trying to discover
I'm on develop discover and develop new new antibiotics
and one other targets we and others have been no
nurse pharmaceutical companies in fact to be interested in is a sec yes add
protein I mentioned earlier on
am and so after said
I'm I'll give you a different perspective on the on the on the the GFP
fusion and this
this image this in this image we've got a three-dimensional images the cells
we've actually tilted so then started looking down through the
to the the Rings you can actually look along the cell and now we see this
beautiful ring structures
that %uh that are being formed in in Virginia well in every cell that's
actually buy two
undergo division so
am and with
colleague said it's been a critical prices I see there I want to
am ex-members a price is here we succeeded in developing
am in heaven is about this said specific inhibitors attack is said
and and actually showing that they were had had concern with sensuous
antibiotic so this is the movie already seen this is the movie is cells which
have been
treated with the specific inhibitors the FDA said
protein we'll see if they grow quite well for a while
the elongated but they don't divide that eventually become unstable
and damn if you if you look at the end of this cell you
you'll see that again just like the palace untreated cells they the kind of
explode
the tip so we think that 10 things these compounds do apart from blocking
solution is they result in
and disturbance have the the final division that occurred
one when the company was added and
I'm eventually these films become unstable and A&E
you can see the all the biomass here all the growth occurred
and friends the antibiotic is Israel if your child because the sellers going to
cookers so the we were very excited about these
these compounds and invested a lot of time and effort in trying to
develop them and I'm several years ago we were successful in getting a piece to
prefer principal
that we could find & Noble am potential antibiotic my clothes that would work on
this new target FTS
said again it's so silly souls synthesis miss the papal
went very proud of from from some years ago now this is one the compounds that
price is developed
and we were able to show that and just
these companies don't just killed the some suppose cells which are which a
nonpathogenic but they also kill
stuff a cock suffer caucus and even I'm methicillin-resistant Staphylococcus
and they'll do that in an animal model of infection
an sadly am
these compounds are not yet in development I think the stalls pi love
interest in
in developing these molecules are other after a sudden inhibitors
but so far issues such as the development of resistance
have stood in the way of actually getting these compounds I'm into
clinical
clinical trials but I think it's an interesting prefer principle there are
still
am novel targets out that it could be and exploited by people looking for
looking to develop new antibiotics have and of course is
everyone here knows their day is already a desperate need for
new classes what about it if you use to try to combat the
increase insidious threat if for insidious rise the resistance
so everything I've told you but so far
and has stressed how important the sole ball is and you
you'll see that my love's been working on soul census cell division
and regulation soul census for for many years now
and and so a few years ago we could become addressed miss
really puzzling question about how how cells have
how bacteria can survive and maybe even strife
and the complete absence in the cell wall am
been and so the
do it do in which she got into this problem was that there was a long letter
literature
of work on bacteria called Al forms on and he's a beast of a month
are also called so we'll division back here so they were first described
am each year so years ago and by
any plain burger and just have I am preempt a question that often get asked
but where the hell came from an 04 it is time for the list Institute in London
where
meme Kleinenberg I was was working so it's
there's a huge literature on on the Sun on these
alfonse and many many from clinical situations where where people have been
am treated with often with happy like Tom
penicillin like antibiotics and which actually select
for organisms that can grow in the absence of a cell wall
beam sorts of apps can also be made by me in
in vitro by a party by treating cells led by such a great hands on saddam is
the wall
you have to retain them and special coaching media
to prevent it from bursting because it up took a problem that I'm
I mentioned and have been implicated many chronic illnesses and diseases but
the problem is that the organisms a very slow-growing that difficult to culture
and the evidence is often very weak hand there there are
most the report I'll individual case studies
and the controls are often am either completely lacking or
a quite put and one in the pic from says that there's many from the prima que era
when it was really quite difficult to to study these organisms
and added a recent PubMed search just to look for alphonse
publications on now forms and we'll see is that there's a
the big pic about on papers back in the seventies and eighties but that since
the Solomon actually era
love the ninth nineteen eighties and the number publication is kinda dwindled
and in fact I think I would argue that it wasn't really until about five years
ago
when we could start to do whole genome sequencing you taking advantage the new
DNA sequencing methods that we really started to have the tools
to be able to look at the south from question properly so it would become
excited in trying to understand using modern my kid
genetics am with have what games if you like with the
with the cell phones so the heroes are the story in my in my lab on Richard
dunno
just there I think and and Marc Marc levy moccasin
the rich is a long term so soon mine which democracy
graduate student who stayed on one first down for you to do a high-risk
high-reward kind of
project before he went off to become a postdoc I'm working on
wilms' Inc so they they develop a tractable system for something awful
biology
using our favorite poem is a Bacillus subtilis so
there's a technical morning here so this the next few slides will have a little
bit of technical detail on psychology as those
view rough am no no Michael my probable
a little by little background but so this show see that the method that we
used
to develop their phone system so
the the census is a cell wall
and has been well worked out over over many many decades
and the basic raw materials for soul synthesis are actually synthesized
inside the cell inside the cell membrane and they're a series of enzymatic
reactions which are well
1.oem shown here which lead to the formation is this
small molecule called lipid to which is then flipped
to the membrane to the outside and it's not assembled into the existing
so wat to make the vis a vis beast new stitches that are being put into the
soul fabric son and B subtilis
it turns out that the genes that encode five of these enzymes
I'm sit together a little cluster and the call regulated
so the regular turned on and off together and so we use genetic
engineering
to to alter the regulation of these genes
so that basically the synthesis if these five enzymes
expression of these genes
is dependent on whether or not I'm a simple sugar called xylose is present in
the medium
if you put silos in the region then these enzymes are all made
if you turn on the enzymes are made souls into this proceeds normally
and but if you take away the xylose any shutdown expression will these jeans and
have a multiple blockade in this pathway
which which prevents the cells from and
from improvements both expanding the sole so cut a long story short
am we those cutler 10+2 technical difficulty in getting this to work but
eventually became a protocol which worked
and which which is shown here with to the cell walls we put in
and a lot of sugar damn as knows more like to prevent the cell from bursting
due to its
I'm to get we we'd have no xylose in the medium
to prevent the cell wall synthesis through the route that I mentioned
previously
for technical reasons we have another biotech selection against the room the
roads in there had to be like time
Palace on antibiotic and what we found was
that we needed to have at least one additional
mutation so in addition to shutting down the sole synthesis
so if you like I'm in addition to that mutation we needed a second mutation
to get the health forms to proliferate with that mutation
we'll end up these things that look like classical Alfonso
very very different morphologically from these wall tiles
and but this very heterogeneous genius some
am population sows is typical
the Sawtooth of warm and organisms which have been reported in the literature
available in many
decade so
very early on in this project no two huge surprises in this is the reason why
we're still working on this problem
back very hard right now the first one is not
this ft is a division machine that i've been talking about in man
I'm telling it was a wonderful talk that perhaps both
new antibiotics becomes completely dispensable in all forms
so here's the experiment we published a few
few years ago now and we we take this act as a gene we engineer it so we can
turn it on or turn it off
in normal cells if we turn off the aft as a gene
then we get this extension of the if the salad the filament
and then it and then the burst and so that's completely full
but in the iPhone background am the
it makes no difference at all to the growth for the the cells whether or not
the tone
deficit gene on or sort of the referees first process a go even further
and and so we we show that we can completely delete the FTS a gene we can
take it away completely from the cells
and it makes no difference whatsoever to the proliferation of homes so the of
bombs
must be using some completely different motive proliferation
to the one that's used by virtually all the bacteria on on the planet
in normal circumstances so that president raising questions about about
how their phones actually
would proliferate and he was a the second surprise
am and that isn't gonna show you this
this movie this is how normal wall tiles grow
and this is what the hell forms how the awful proliferate so
will seek and the there there are heterogeneous there are there a very big
ones there are
and and actually tiny Elf on something repeated
sort of cheap Yamashiro here which she you can see very well
and when you look at them the motive proliferation its
am it's really high I slung from the right adjective to describe this I mean
basically the whole
the whole thing is quite a Mac a mess them it's very it seems very haphazard
am and and and heterogeneous and some cells
you see this spontaneous I'm emergence have several small
tight are tiny progeny cells sometimes EC
chain have cells being been generated am
but it's very rare to see cells that appear to be doing any
thing like binary fission it's very difficult to see anything in these these
movie so what what dennis is show you a couple still sequences that illustrate
some other common events that occur in those movies
so one kinda eventually see this
round now form and growing in size and then it starts to elaborate
distributor structure which then growth and eventually breaks down into a chain
have book party connected progeny so you see the emergence a five or six hours on
a single event
him and his here's another larger a form
again it's more a spherical n you start to see his pulsating
changes in this the cell surface and eventually there's an eruption at
several points on the cell
have a series of small am small progeny cells
so they're very very strange am
even securing these these are from so we think the
this these are preferred events you can follow these
he's baby cells and watch them grow Anand ago
similar kinds a proliferative changes so
wanna reef I'm I'll tell you in a moment that we've been studying this mode for
the shit freshen and a lot of detail
from the last few years the one other the questions we had was whether
these very strange events that we've scene for be surplus would actually
apply also to other bacteria some
the last year so we looked at a couple with a very diverse bacteria
crying too much in baton macum is another gram-positive bacterium like the
source of course
but it comes from a completely different lineage of the gram-positive bacteria
an e.coli of course is a well-known from negative bacterium
comes not either completely different the two groups a picture that were
discovered by
by Graham man 130 years ago this
this comes from the other group ferguson's a billion years a few
missionary divergence between the cells
when you look at them when you convert them to all forms using more lessons the
methods and I just told you about
then you see that they they look remarkably similar so
tranny fucks him actually goes even better than the solace in
in liquid again it shows you the choice is very kinda haphazard
blabbing tribulation kinda process
eagle eyes a little bit different am that this is going on in liquid
as a pass for the peace unless all forms with the E coli all forms have been
unable to get them to grow
income no in a complete liquid medium so they're Delta going honest semi-solid
am a call me Jim here but again you're seeing
rather similar prolific vans you know given that the cells are partially
immobilized
am began it's a very non now
very haphazard non-binding the fish in like process it's being
its gonna be wanna go in the south and
in on earth questions that you know what I think answer no
have finally am relates to the question about
how different these these all forms of from
you know how to define actually I'll from bacteria and
and so what we've been able to do again in E coli just as we did for be subtilis
is we've been able to one want to generate these all forms
actually show the Beacon delete these key central G
and television jeans the act as a tree in another solution genes in a little
while synthetic genes
once you turn these into alphonse you can complete his friends who love those
two streams so these days are remarkably different from
both cells but it looks as if the summer kinda process can be followed
in very divers branches are the bacterial
to me okay
begin solve the last am
few years ago mentioned we've been
and pursuing am
the a sort of molecular basis for our form division and and these are some
other people who've you leaving
playing prominent roles in the lab over over over several years now
and I won't tell you much about this because a lot of love this work is now
now published but we think we can identify several discrete steps
in of nonproliferation for each of the steps with you know it'll to identify
genes that be so lets users
to be able to carry out i'm too good to go to proceed through those
two steps and so on in the last on the next couple slides on fact me the next
slide
I'm really just gonna focus on one am
piece of work to do with the the growth in deformation which i think is
the the most informative
happy some research that we turn on your forms to my job really to the model
we have now for how alphonse proliferated so
we we were very uneasy with this this model we publish this affected by two
years ago
go now in but it turned out that all other genetic evidence that we'd be had
and all the imaging information that we had
pointed to and what we thought was an unexpected
model we were anticipating to begin with that there would be some kinda
protein-based machine
that would bring about this division process because as always approve
protein machine in
in biology am it tonight in
though that the at least the genetics every everything all the data submitted
told us that all you need to do
to be able to generate now form is to actually increase the rate
membrane synthesis see you on balance the normal
am regulate regulatory link between
am expansionist Pro for the cytoplasm go through this
surrounding song some members and certainly to model looks like this
you start with a sparkle cell and which has
just the right amount of membrane to cover the surface of the sphere and then
if a margin that you have
but what would only you too much would happen would be that the south will
regulate the senses a membrane
food as a growth it will it will maintain just the right amount of
membrane to cover the surface of the sphere
however in the health forms they actually
I'm am make excess amounts if membrane what what happens then
is from simple job geometry and the only way to lose the excess
and surface area is to change the ship with the cell
because the soon as you I'm
because this object to this crazy shape
requires much more surface and much much more memory to cover its surface
then a spherical equivalent because in time for you
some simple geometry BBQ somersaults in the woodland
that's cool
so the definitive this is a view make access membrane Yorkshire Drive
anti-fur mission to sell if you take back to its to its logical extension you
can
you can even pinch of the sum these loads that are generated
and that generates and a bunch of smaller cell progeny
and again because it's simple geometry the and
the collection of smaller cells a degenerate know the total surface area
dove the small cells is greater than the surface area of
the single cell equipment total volume go
product make sense but I'm will try to convince you that this model could be
right
I'm you know by the end of the talk so this is the model we are forced to
to to go to its extremely simple mechanism it doesn't require any kind of
complex protein
machine we all you need to do missus again with the next house he is make
more membrane
and the cells will spontaneously carry out this kind proliferation
but you need to have the access member instances so now those %uh view
Namlook to my title carefully will be wondering and where the origins life
starts to come into this and so better now than when we started to look at the
hair started think about the this model for a form
proliferation the rehab start reading about am
how how membrane vesicles behave and another
actually lettuce into into the story that I'll tell you about bike right now
so an extra three sides are just gonna tell you what what current thinking
is as I understand it and for how but the key steps were in
in the version of life life on Earth enough drawn from a
very nice chapters which Lohse growth very very soon shed with me call the
origin will you ship
life and so the first the first key step
in a new mission in life was the availability of the
small precursor molecules like amino acids nuclear bases and and fatty acids
which are used to make the the the proteins and nucleic acids and
membrane material and the goat got it makes make South
and so the idea is that there was a kind a prebiotic soup the content these
things in abundance and that was my life eventually merge
and I think
I'm on thinking am and is
is that DD's cut kinda coming Obama building blocks could indeed have been
available on the early earth and thus also those could either have been
I'm from space outer space because I think chemists can now
spectroscopy Scannell detect these kinda small molecules in
deep interstellar space and a deep and interstellar dust
ort also possible they could have been formed on the only earth
and doesn't there was some amazing experiments carried out
am in Mission this hypothesis I'm back in the nineteen fifties
Pabst and Miller did his experiments where he took
and imagine the sort of gases that would have been around a nearly
early Earth things like me sane and monument I'm
hydrogen am he put those gases into a cylinder he
bold bold wanna so you had more difficult through this the song that the
men had an electric discharge
here on the experiment for am good how long queue to time
and then look to see what kinda molecules found out into the into the
solution down here
and what what he found in these experiments was remarkably you can
generate
from from this kind of experiment and I'll a large
proportion of the key ingredients that you need actually show up for life
so it seems that this this step in in biology is probably
am reasonably well on understood at least in principle
the next next step is to go from
the soup to something hasn't kind of information content
and I think again a lot a scientist would would it would agree that it's
very plausible
that the first am information containing Malik molecules that were
around on earth on on which you should know processes could start to
to I'm develop and with was based around
the so-called arnie Wilton and so the idea here is that am
critically am are our news and information store like like DNA is a
sequence a basis which can
which can encode information but critically
unlike DNA arnie can also fold it
I'm into complex and structures like this one and in this
in the states these armies can have catalytic properties so they can
cut-price reactions that now it is a problem we have allies by enzymes by
protein enzymes
but as P prebiotic world
am the art yarn aids thought would have would have been carrying out a lot of
the early
chemical reactions unusual life and what's beautiful but this is the
catalyst
contains the information that's that's needed to accord itself
and so you the idea this would be the DNA and proteins would simply later
improvements that
the this was a better stored storage molecule for information proteins were
but I catalysts am but you know for sure that the suspect elation and probably
give you time machine to go back to
as I understand it and efficient autos are the
the this field now I'm I'm and now recognizes two key steps in the third
step
am been requires some kinda fact container
because for Darwinian selection to begin on those on those arnie molecules with a
diverse sequences and their different catalytic properties in a sum would be
better than others
for that for the catalysts and two to actually
on the undergo any kind of selective I'm and enrichment
the the the RT molecule and the products that it generates need to be cont Mitt
need to be retained in some kinda containing
and am it's now it's now 4 again plausible that this disc
the content was probably fatty acid or lipid based
because fatty acids and lipids will spontaneously
and assemble into membrane vesicles
and and it's all it's thought that molecules like
by fatty acids lipids were probably again present in a prebiotic
soup some finding witnesses where a lot of thinking damn has moved to in the
last few years
is the question about how this member in container actually could have
could replicate ish so it's all very well having lipid vesicle with arnie
molecules in
been small molecules inside it but how how can I am fat vesicle
have proliferate to generate to fascicles
and retain to produce a varney in and so this is dad truck struck just like is
one of the
them mean a.m. proponents at this dis
stage in ministering the georgians light rain and
so it turns out when you when you look at the letter showed that the people who
are really interested in origins of life
power have have concluded that I'm its its
in principle very simple to am enable these vesicles to proliferate and
written in fact
so that's the theory is actually filed by Wilbur well worked out
and the keeper ominous turn out to be increasing the surface area to volume
pressure am and secondly that the the vesicle should be relatively impermeable
so that when you start to make a shift change them the water doesn't just
to be russian am beloved everything but in principle at least in theory
you can drive is kinda shape changes new proliferation
simply by increasing surface area to volume pressure the
the experimental by officers are gone one step 4: further
and so again around my 2009 and this this paper beautiful paper was published
and there are their numbers
summer kinda papers but particularly like this one and so this is a simple
in vitro experiment where the they have taken
phospholipid vesicles so this is a sin simple
single phospholipid chemical species
which has been assembled spontaneously in the test you
into these cycle physicals but they've ended
with and he's a very stable they will sit there for for many hours
but it ended was to start to feed these vesicles by adding
fatty acids to the to the medium and those fatty acids Olympic late into the
lipid vesicle increasing its surface area so they can
replicate the theoretical X window shown in a previous life
and when you look at what happens to those those pasick als you see these
amazing person
proliferative FNC is a was blown up
he's a sort of jubilation kind kind event to securing some of these when
there's a little bit a mechanical agitation
and what we would became very excited about was the the fact that
these these images look very reminiscent of the
the pictures that we saw for the album proliferation
so and with a very excited by and the sort of convergence have the top down
approach that we've been using to sort a strip I would have
the cell wall something machine with a division machine yet from bacterial
cells to
referred them to some kinda primitive state and beaten with which is converged
with the bottom-up approach that the origins of life groups have been
and using to try to assemble am the sole two structures that could have been
used by primitive cells to proliferate so I think it's
it's going to be very exciting I'm Ariary fervent risk
for us we think that the iPhones provide a very interesting model system for
full I'm in future studies on on the origins
a flight from home very primitive cells could have come about and it's also
interesting to speculate
I'm just coming back to that point I made failure on
about the the first bacterium already having a cell wall
am been of course you can imagine that before the soul was invented
then maybe the bacterial cells actually proliferated like the all forms that
were describing here
in which case the invention of the cell wall
structure synthesis could've been defining moments in bacterial
you lucien allowing bacteria to escape from their
muddy puddle where they down which had them I first evolved
to get out onto the planet and and colonize the whole %uh punish no love
the
and generate all the diversity and abundance of picture phones that we see
today so that
I'm that really brings me to I'm
towards the end you talk now I am got one final Alchemist
slides to go and I'm and this was just a summer in a perspective
but I've tried to tell you about and the key things back to all the battery very
small
direct incredibly sophisticated in structure and function at all but shown
you that
many bacterial proteins perhaps most proteins have a very specific address is
that they go to and confined in the cell
to go there to perform in very sophisticated functions that they carry
act
of all the structures in bacteria
the cell wall in a census really and months as the most important it's a
crucial
structure from 450 to the south support for shaping division
a superb target for antibiotics perhaps the future and parks as well
remarkably though back to reckon escape from seoul damage
by switching to this Sam our form state and they could do this with me only one
or two mutations in the seems to be conserved
across from perhaps the whole the back to am I'll follow Jimmy
we think that the cell phone the studies of on some
wide-ranging implications week and matching using them as model systems for
studying
wilson has a subdivision basic science because you can delete many other genes
that
that am that we would only want to to study
and his love interest in using these these kinds of approaches to generate
artificial cells which might have water by technological a problem
applications the still huge question
clinical question about whether all forms of are important for recurrent
or persistent infections and finally there's this
really interesting question and by the potential
above using of bombs as models for the your chance at life
and that the pics nothing to the last blast site
I have to acknowledge that none of them were gonna talk to vice
tonight was actually done by by me am I've been
exceptionally am lucky to how to host
string of very talented in time I dedicated research has confirmed through
my love the last twenty-five to thirty years
this is the the present the present group outside a
however I'm every building to the people these other
these other the current crop of
I'm have students in for stocks whose shoulders I stand on
I'm privileged to stand on in damn
presenting this the signs are to you by tonight
well have fun quest
Chur question yes
there's someone in the second row up
lady in the finna my head
jumper her thats Meyer tip
my
Canyon yes I few told us how these L forms or or indeed the workbook
to your deal with asthma depression and no haven't
and even I think that's one sister that one
is thats you can and what what one possibility is the actually only live in
issues where
there is some kind was Monica support and so you can imagine and
certain clinical situations you know the extent could well be
you know and serum and it could well be the some
man fuck you know that some of us can survive in like blood and serum
the second possibility is it did not rain no forms to grow on lower and lower
pas pas ma dick media would be slim stand exactly how that works but we have
al forms that are growing
and you know without any added sequels to
am normal microbial culture medium so
so we kinda country in them without too much difficulty to actually grow I don't
own standard by physics at
them but all your in warmer your slides there was a
it looks as if there was a gene product involved
in the server nipping offer the small I'll
form
that was up correct interpretation not be
really am monument in the the schematic slide well yeah I what we we look for
mutations that some
that are the block of on both specifically
right and and so if we found we characterize one mutation in a lot of
detail
am and it turns out to be involved in member in
since this again it's it is involved in the commission a branched-chain
fatty acids are and Andy's French in fatty acids are responsible for
controlling the membrane fluidity
so we think that the disputation reduces member incivility and then
decision event that you need to to separate those cells
occurs less efficiently am if you have a
on a high and maturity some we don't think is a specific position
we were very much hoping to get proteins might be involved in session for
than with always the only fun things and affecting member instances in the
about four rows back thank you from
interesting talk when the new forms divide into a variety of different sizes
have daughter cells
I'm what's the DNA distribution of the large ones Molly bloom
your at that's a great question with for for a long time we really struggled with
a question you know I'm interested in chromosome segregation as well
superheated gas and it's extremely difficult knows
those imaging company those imaging conditions to actually track
the cells and in detail so so
we haven't really started to memory figured out how to do until very
recently in what what we've been doing
very recently is to use I'm microfluidic systems
so it turns out that if you drop in our form into a channel which is about to
the same size as a as a-rod and the future of the awful me know so he kinda
constrain them into
by the right size rod-shaped the actually then
and grown remarkably well and you can follow from some segregation when I see
no cells and a segregated
not not as well as the wild-type but that pretty well
so and I think it's it's it's a geometric from the date they have 18 you
know and I used to growing as it were in
in a straight line and segregate in the chromosomes and enlarged Munchen
axis and pointed that would become three-dimensional the
whatever the mechanism to bother the use don't work very well
yes
just be well two rows behind you %um
their their back
in the a fascinating smart you sold
although division every 20 minutes
home presumably something must've been feeding these bacteria
in yes though is that through two cousins rules
dad that the this is a the a typical back-channel growth media
so it would commonly have you know sources of carbon and nitrogen
and so so for and trace trace elements
plus often a carbon source like
likely cause a common energy source like because and
often amino acids and vitamins and you're there
classical I'm microbiological
culture media you can use so they're all horribly and was commissioned was a
semi-permeable
to those I am molecules
yeah there's something from people they also have I mean what about you have
incredibly sophisticated uptake system so they have to have their transport
proteins that will grab
in a particular kinds amino acids and transport them into the song with the
rules in the health room presumably the accesses
much last time
betwixt it could be yes a.m.
not some interesting it's interesting but we don't in 10 things you can't ask
actually using the system is the question about the the extent to which
the war plays a role in it as a barrier to
not for some small molecular take but also to protein secretion
because proteins guy have to go through the through this whole so we can look
see what happens when there's no wallet mom
thanks yes
thank you very much you talk in I bring
preaching from the clean who hasn't in have cheap and pretty
bosses bus has anyone done anything remotely bacteria
in this line corneal forms know it it's interesting that very little in from her
so the the question was whether a customer things apply talk here
you the other major creeper back good over
bacteria am that this very little information on Alfonso
fam archaea am and its its
fun interesting question i order Reglan review on this that was position open
biology
and right side is I'm open access Journal couple years ago
am that the thing is our key I have a completely different cell envelope
structure they don't have a pic like I'm so warm so these are the two use
different strategies different molecules to
enveloped the cytoplasm so it seems possible that the the two groups have
organisms actually much separately from the
the primordial soup as a result of inventing
different am sign in below structures
so the fact that I can wall was invented by the put became the bacteria
and the the other kinds of both pictures were invented by the hockey and that
they want their own
them separately but damn very well known about
about your key
like fascinating talk I wanted to ask you
how similar or different are health forms to Mycoplasma
subtly Mike yasmin is one state have assailed cool a superb shaded
yesterday pollution such as wanted yeah I am
it's thought the mycoplasmas I am which which has he said don't have any solo at
all
am came from from from removed from
the same lineages as B subtilis and Clostridium
but so so they're probably descended from back to that used to have a cell
wall
am and what what did you can imagine what happened was that the
the did there was a there was a plus for him it became an
became now formed by using its wall and then
find some kind even I'm environmental and advantage by
by doing that and did nothing about the the microprocessors if if you look at
the
the that most of them actually are tightly associated
intimately associated with the you carry out a car or prior organism host
so they probably evolved having lost the wall
the differently than undergone a lot I V lucien in a in a direction that's helped
them to
interact with their host cell which has resulted in
in them being very evil missionary different from from the from your phone
to the orphans a very similar
only twenty-two patients from existing wall tiles
was the mycoplasma route you know gonna be one hundred million years have
you shimon my yes
but i just wondered you mentioned you grew the
cells under microfluidics and that changed the
the regularity the the the progeny
did you also tried SMA chemically stimulating
the growing medium while the cells being grown because presumably in
the original bombs like hot hyder some hydrothermal vents
kept the bill autumn mechanical stimulation of that yet such a good idea
russian mature really explored that to the idea would be that if the
you know by now he does is deliberate vesicle experiments if you had to take
those you actually can increase the rate of proliferation so
I think we've actually look to see whether that I'm I would happen in
added to the often so should we should try to so I can get a better rate of
proliferation fine
budgeting yes last long
now
you you liken the peptide like him to a string vest
I think I'm do you think like a string bass there's only one
lehrer tutsis for the surface or it is there anything in the year
the radial direction is it would be on on on the bacterium
showing its and it turns out that the gram-negative bacteria
am don't you know that one was major groups am it looks as if it's almost a
single
where so like like the string best but in the gram-positive bacteria might
notice from the electron micrographs such a very thick
much thicker live have to try come so
so it's like cam it's like a series of layers and
I think at this stage 1 10 the big on solve problems in
actual some biology feel like is understanding the
ultrastructure of the have the sole more particularly gram-positive bacteria so
it's multi-layered in gram-positive promising all their incomes
okay I have
one more thing to do and others well two things want to thank you for a fantastic
talk
here I'm how you brought up so much into
current research I think was just wonderful are from our and then I have
to give you this
three things
one keep play metal amber
guess a scroll some sort thank you very much