Horizontal Acquisition of Prokaryotic Genes for Eukaryote Functioning and Niche Adaptation

Abstract

Horizontal gene transfer (HGT) is a major mechanism of evolution, in that it is pervasive and can dramatically affect lifestyle by allowing adaptation to specialized niches. Although research has mostly focused on HGT within prokaryotes, examples of inter-domain transfers from prokaryotes to eukaryotes are increasing, and such inter-domain HGT is emerging as a very significant component in ecological and evolutionary terms. Here, different cases of intra- and inter-domain HGT conferring an adaptive advantage to eukaryotes are reviewed to examine novel trends and HGT paradigms. Thus, HGT appears to play an important role in eukaryotic adaptation to specific environmental conditions, including in the ecological evolution toward parasitic lifestyles and pathogenesis. The diversity of prokaryotes and their genetic potential are emerging as a vast reservoir to foster rapid eukaryote evolution.