Subscribe free to our newsletters via your
. 24/7 Space News .




EXO LIFE
How did early primordial cells evolve
by Staff Writers
London, UK (SPX) Mar 04, 2013


Although genetic mutations associated with the L-form state have been identified, little is known about the molecular mechanisms underlying L-form replication.

Four billion years ago, soon after the planet cooled enough for life to begin, primordial cells may have replicated and divided without protein machinery or cell walls, relying instead on just a flimsy lipid membrane.

New research on bacteria examines exactly how these primitive cells could have evolved without such crucial structures. While the vast majority of bacteria have cell walls, many bacteria can switch to a wall-free existence called the L-form state, which could mirror the structure of primordial cells.

A study published by Cell Press in the journal Cell reveals how bacteria in this L-form state divide and proliferate, shedding light on how the earliest forms of cellular life may have replicated.

"The main surprise for me was how simple the mechanism was. It doesn't require any sophisticated protein-based machinery," says senior study author Jeff Errington of Newcastle University. "This makes it plausible as an explanation for how very primitive cells could have proliferated in the very early days of evolution."

The cell wall is a layered structure surrounding cells that protects them and maintains their shape. It is present in all known major bacterial lineages, and it was also probably present in the last common ancestor of bacteria.

This structure is so important that it is targeted by antibiotics, and many bacteria responsible for infectious diseases can switch to the L-form state to resist antibiotics.

Perhaps the most striking change associated with the L-form state is the way that the bacteria replicate. Instead of relying on precise, complicated cell division machinery, L-form bacteria become irregularly shaped and form cell surface bulges that pinch off to become daughter cells.

Although genetic mutations associated with the L-form state have been identified, little is known about the molecular mechanisms underlying L-form replication.

Addressing this question in the new study, Errington and his team identified two genetic changes required for L-form growth in bacteria. One of these mutations was necessary for the increased production of fatty acids in the cell membrane, which would be expected to increase the cell's surface area relative to its volume.

Indeed, the researchers found that by artificially increasing cell surface area, they could induce L-form-like shape changes and cell division. The findings suggest that a simple biophysical change-an imbalance between surface area and volume-underlies L-form cell division.

"Our study paves the way for understanding how L-form bacteria cause disease and resist antibiotics," Errington says. "It also offers a model system for future experiments aimed at exploring the possible replication mechanisms of primitive cells that could have existed before the explosion of bacterial life on the planet nearly four billion years ago."

Cell, Mercier et al.: "Excess membrane synthesis drives a primitive mode of cell proliferation."

.


Related Links
Cell Press
Life Beyond Earth
Lands Beyond Beyond - extra solar planets - news and science






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








EXO LIFE
Toxic oceans may have delayed spread of complex life
Exeter UK (SPX) Mar 04, 2013
A new model suggests that inhospitable hydrodgen-sulphide rich waters could have delayed the spread of complex life forms in ancient oceans. The research, published online this week in the journal Nature Communications, considers the composition of the oceans 550-700 million years ago and shows that oxygen-poor toxic conditions, which may have delayed the establishment of complex life, were cont ... read more


EXO LIFE
China to use modified rocket for moon landing mission

Water On The Moon: It's Been There All Along

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

EXO LIFE
Short Bump Gets Robotic Arm Closer to Rock Target

NASA fixing computer glitch on Mars Curiosity rover

Inspiration Mars to Pursue Human Mission to the Red Planet in 2018

Computer Swap on Curiosity Rover

EXO LIFE
Tech sector rides on rich list

Brazil inventor struggles to collect royalties

Stanford scientist closes in on a mystery that impedes space exploration

U.S. research to be free online

EXO LIFE
Welcome Aboard Shenzhou 10

Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

EXO LIFE
ESA's Columbus Biolab Facility

SpaceX set for third mission to space station

Record Number of Students Control ISS Camera

NASA briefly loses contact with space station

EXO LIFE
SpaceX's capsule arrives at ISS

Dragon Transporting Two ISS Experiments For AMES

SpaceX Optimistic Despite Dragon Capsule Mishap

'Faulty Ukrainian Parts' Blamed for Zenit Launch Failure

EXO LIFE
Scientists spot birth of giant planet

NASA's Kepler Mission Discovers Tiny Planet System

Kepler helps astronomers find tiny exo planet

Searching for a Pale Blue SPHERE in the Universe

EXO LIFE
SimCity rebuilt for modern life

Taiwan turns plastic junk into blankets, dolls

Fukushima raised cancer risk near plant: WHO

Ancient Egyptian pigment points to new security ink technology




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement