Saturday, 15 November 2014

Archaeal origins and bacterial gene acquisitions

A phylogenetic analysis of more than 25,000 archaeal gene families found that the integration of bacterial genes into the genome paralleled the pattern of archaeal-specific genes in each of 13 orders of archaea, suggesting that archaeal lineages picked up groups of bacterial genes at the time of their formation.

About a third of the archaeal genes analyzed had homologs among bacterial genomes, and the phylogenies of these apparent genetic imports closely mirrored those of archaeal-specific genes in each of 13 orders of archaea, suggesting that the birth of each order coincided with the gene acquisitions.

The phylogenies revealed that 83 percent of the bacterial introductions occurred in methanogenic archaea, which are thought by some to be the most ancient groups of archaea and have a simple metabolism—anaerobic reduction of carbon dioxide to methane in the presence of hydrogen gas.

The conclusion that archaeal lineages abruptly picked up large groups of bacterial genes at the time of their formation, though supported by statistical tests, will require further analysis.

For further information, see Nature "Origins of major archaeal clades correspond to gene acquisitions from bacteria."

 Posted by Tim Sandle
(Reference: The Scientist)