Horizontal gene transfer accounts for the majority of prokaryotic
John Edser
protein evolution
Treangen, T.J. et al., "Horizontal Transfer, Not Duplication, Drives the
Expansion of Protein Families in Prokaryotes," PLoS Genetics,
7:e1101284, 2011.
http://www.the-scientist.com/news/display/57962/#ixzz1CO8ZiQF6
...at a meeting last summer, there were those that thought that bacteria
genomes expanded mostly through duplications and others that argued that
it was due to gene acquisition.."
"Prokaryotes, including bacteria and archaea, thrive in diverse
conditions thanks to their ability to rapidly modify their repertoire of
proteins. This is achieved in two ways: by receiving genes from other
prokaryotes, called horizontal gene transfer -- the nefarious way that
bacteria acquire antibiotic resistance -- or by gene duplication, in
which an existing gene is copied, taking on a new or enhanced function
as mutations accumulate."
Past analyses using few, distantly related genomes estimated that
horizontal gene transfer contributes to, at best, 25 percent of the
expansion of protein families -- that is, the addition of proteins with
novel functions or structures."
..."80 to 90 percent of protein families had expanded through horizontal
gene transfer. In addition, the researchers found that the two processes
have different evolutionary roles: transferred genes persist longer in
populations while duplicated genes are transient but more highly expressed."
JE:-
Are these genes "selfishly" allowing themselves to be horizontally
transferred to different organism bodies or are they being employed by
fertile prokaryotes to increase their own Total Darwinian Fitness?
Regards,
John Edser
Independent Researcher
junyDada
this. Her book is an interesting read:
"Acquiring Genomes: A theory of the origin of species" by Lynn
Margulis and Dorion Sagan
Regards
Junaid Akhtar
Perplexed in Peoria
> Horizontal gene transfer accounts for the majority of prokaryotic
> protein evolution
> JE:-
> Are these genes "selfishly" allowing themselves to be horizontally
> transferred to different organism bodies or are they being employed by
> fertile prokaryotes to increase their own Total Darwinian Fitness?
As you know, John, Darwin suggested that a few ancestral finches were
'horizontally transferred' from the SA mainland to the Galapagos.
And that then there were further 'horizontal transfers' of finches
between islands.
Are these birds "selfishly" allowing themselves to be horizontally
transferred to different ecosystems or are they being employed by
living ecosystems to increase their own Total Darwinian Fitness?
I realize these are genes and finches rather than geese and ganders,
but I thought this 'saucy' question might prove thought provoking.
William L Hunt
<ed...@ozemail.com.au> wrote:
>Horizontal gene transfer accounts for the majority of prokaryotic
>protein evolution
>
.....
[snip]
.....
>JE:-
>Are these genes "selfishly" allowing themselves to be horizontally
>transferred to different organism bodies or are they being employed by
>fertile prokaryotes to increase their own Total Darwinian Fitness?
>
A prokaryotic strain that "discovers" a new beneficial gene would gain
nothing by allowing it to be transfered to a completing strain or
competing species. Doing so might lead to its own extinction.
However from the gene's perspective, it would "selfishly" want to be
spread (horizontal transfer) far and wide and behond. The gene would
not care a whit if doing so caused the extinction of the prokaryotic
strain that initially created it.
William L Hunt