A comprehensive census of horizontal gene transfers from prokaryotes to unikonts

Tuesday, October 09, 2012 — Poster Session I
1:00 p.m. – 3:00 p.m	Natcher Conference Center, Building 45	NLM	BIOINFO-15

* FARE Award Winner

Authors

• P Puigbo
• S Mekhedov
• YI Wolf
• EV Koonin

Abstract

Horizontal gene transfer (HGT) is a dominant factor in the evolution of prokaryotes. However, in eukaryotes, the impact of HGT is generally assumed to be much lower but has not been thoroughly analyzed, with the exception of the massive HGT from the endosymbionts. Here we report a comprehensive census of likely HGT events in different groups of unikonts and an in depth analysis of a conservatively defined minimal set of transfer events. We analyzed complete sets of protein-coding genes from 36 species of Unikonts (1 Archamoeba, 1 Mycetozoa, 18 Fungi, 15 Metazoa and 1 Choanoflagellida). HGT candidates were initially identified by the DarkHorse method. These initial candidates were analyzed in detail using taxonomic breakdown of database search results and ML phylogenetic analysis followed by statistical tests on tree topology. Overall, we detected 1768 probable HGT events from prokaryotes to unikonts. Approximately 90% of the detected transfers were from bacteria and only 2% from archaea. The results of this work show that, although HGT is not as pervasive in eukaryotes as it is in prokaryotes, the amount of HGT detected in this study implies that acquisition of genes from Bacteria played a major role in the evolution of the Unikonts.

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