Bulging bacteria and the origins of life

Jeff (left), Romain (centre) and Yoshikazu (right), the team of researchers behind these exciting discoveries


In a paper published this week in CellJeff Errington’s team in ICaMB, have discovered new insights into the origin of life on Earth.


Jeff and his team share their results

Bacteria were the first organisms to appear on planet earth. Almost all modern bacteria have a tough protective shell called a cell wall. The structure of the wall and the mechanisms used by cells to manufacture it are conserved, suggesting that the wall was invented right at the beginning of bacterial evolution, and, therefore, when the first true cells emerged.

Production of cell wall is carefully regulated by complex machineries that allow the cell to enlarge and then divide in a controlled manner, all the time maintaining the integrity of the wall intact.

Despite its importance, it seems that many modern bacteria can survive cell wall loss under certain very special conditions, such as when they are treated with certain antibiotics that interfere with its production, like penicillin. Not only that, but a few years ago my lab showed that these “L-form” cells (named after the Lister Institute in London where they were first described) no longer need the complex mechanisms normally needed for bacterial growth and division. Instead, they grow by extrusion of irregular tubes or blebs of cytoplasm, that pinch off into daughter cells.

Our team – me, Yoshikazu KawaiRomain Mercier – has been working on this problem for some time. “Studying L-form biology is a real technical challenge, and this work could not have succeeded without the strong collaboration established between us“, says Romain. As Yoshikazu explains: “we developed a very simple genetic system to isolate mutations enabling L-form development from non-viable protoplasts.

We are excited because we think we have now solved the mystery of how L-forms grow and divide. Our latest results, published in Cell, show that the mechanism is remarkably simple: it requires only that cells make excess amounts of membrane – the thin porous layer that acts as the outer boundary of all cells, including our own.

Increasing the membrane surface area beyond the amount needed to contain the cytoplasm causes the cell to buckle and distort. Eventually, this leads to pinching off of membrane bags that are ill formed but nonetheless viable “baby” cells.

Time-lapse photography representing the division of B. subtilis without cell wall (L-form). The images were obtained using light microscopy. Scale bar: 3 μm

At first, we thought this mechanism was too simple to be true, we changed our minds when we were alerted to amazing experiments being done by several groups working on the origins of life, particularly Jack Szostak at Harvard, Saša Svetina in Ljubljana and Peter Walde in Zurich. These groups have been wondering how primitive cells could have arranged to grow and divide efficiently without spilling all of their contents. They recently found that simple membrane bags, called “vesicles”, can be induced to grow and reproduce into multiple smaller vesicles, in the test tube, just by increasing their surface area.

So, in explaining how the bizarre L-form bacteria manage to survive the loss of their beloved cell wall, we think we may now also have glimpsed how the first primitive cells could have duplicated themselves at the dawn of life on earth.

Jeff Errington 
Director of the Centre for Bacterial Cell Biology


Cell paper: http://www.cell.com/abstract/S0092-8674(13)00135-9
Cell website: http://www.cell.com/home see PaperFlick
Newcastle University Press Release:http://www.ncl.ac.uk/press.office/press.release/item/how-did-early-primordial-cells-evolve#.US-chen77jQ

Soapbox Science guest blogpost: http://www.blogs.nature.com/soapboxscience/2013/02/28/social-media-from-an-institutional-perspective-why-are-we-on-there

ICaMB website: http://www.ncl.ac.uk/camb/
Facebook: https://www.facebook.com/pages/ICaMB-Newcastle/416200498466481
Twitter: https://twitter.com/ICaMB_NCL
YouTube: http://www.youtube.com/channel/UCSuZgA6URiXTUoHq1tMe-PQ


Welcome to the ICaMB Blog!

One of the most important things we need to do as scientists is communicate, both with each other and with people outside academia and research.  To help this, we will be starting a range of new, interconnected social media activities in ICaMB.  In addition to this blog, we now have a Facebook page and regular updates on ICaMB activities via Twitter.

Here, we hope to have contributions not only from academics in ICaMB but also from our students, postdocs and other key members of the Institute, as well as  some guest bloggers.  We plan to have regular blog articles appear every two weeks but this will be supplemented with the thoughts and opinions of a range of contributors as well as updates on events as they happen.

Our plan is to inform but also hopefully entertain.  We will highlight some of the great research that is going on in ICaMB but also discuss some of the important issues that affect all of us as scientists.  We will value your contributions so if you have something you would like to say, please get in touch!

This is an exciting time in ICaMB.  Although we, like everyone else, are having to weather the economic storm, there is also plenty of great science being performed and new initiatives that make this a great place to work and perform research. The new ICaMB postdoc (IPA) and postgraduate student (PANIC) associations will provide a new voice for some of our most important members of staff. We also have the new IRES, Independent Researcher Establishment Scheme that will bring new principal investigators and ideas to the Institute (more on this later).

Check out the Facebook pages for photos of ICaMB activities and scientists.  Feel free to contribute your own (embarrassing photos of Professors are always welcome). Check out Twitter for all the latest up to the minute information and news about ICaMB activities. We hope you will enjoy reading this blog.

Please join in and tell us what you are thinking!