Microbiology: Building from the Inside Out
By SCIENCE/AAAS
Added: Sun, 13 May 2007 23:00:00 UTC
Thanks to Jason Fabre for the link.
Reposted from:
http://www.sciencemag.org/content/vol316/issue5826/twil.dtl#316/5826/799c
The evolutionary origins of complex organs, which in their current state of assembly feature many distinct components that apparently have no function in isolation, have long been debated. Liu and Ochman have unraveled the history of the origins of bacterial flagella by using a phylogenetic profiling method applied across whole genome sequences to identify a set of 24 core genes in the common ancestor of bacteria. The members of this core set were probably derived from a single gene that had undergone a combination of successive duplication, loss, transfer, and diversification events. The evolution of the flagellar components apparently followed the present-day order of assembly, with the oldest proteins (the rotary motor) being those proximal to the bacterial inner membrane and the most recent (the filament monomers) being the most distal. Hence, the flagellum probably started life as a simple proton-driven transporter that evolved into a more elaborate secretory apparatus--of a sort still found in bacteria today in the form of the type III secretion system--and finally into the self-secretory motility organelle of modern species. -- CA
Proc. Natl. Acad. Sci. U.S.A. 104, 7116 (2007).
Tweet
RELATED CONTENT
"Map of Life" Shows the Location of All...
Rebecca Boyle - PopSci 5 Comments
The Map of Life platform lets you search by species, using either its Latin name or common name, and find out where it is located on the planet. The project sheds light on how little we know about some species. Map of Life Project
Stone-Throwing Chimp Thinks Ahead
ScienceNow - Wired 16 Comments
A stone-throwing chimpanzee named Santino jolted the research community by providing some of the strongest evidence yet that nonhumans could plan ahead.
Crows know familiar human voices
Victoria Gill - BBC Nature 13 Comments
Dinosaur Burps May Have Warmed...
-- - ScienceBlog 16 Comments
Human Societies Starting to Resemble...
Jennifer Viegas - Discovery News 27 Comments
The similarities offer a look at just how ever-growing human societies could collapse.
The brain… it makes you think. Doesn't...
David Eagleman and Raymond Tallis -... 16 Comments
Are we governed by unconscious processes? Neuroscience believes so – but isn't the human condition more complicated than that? Two experts offer different views



















Comments
Comment RSS Feed
Please sign in or register to comment
View Comments Page