Figure 5

Lateral gene transfer events of bacteriorhodopsin, bacterio-opsin associated chaperone and bacterio-opsin associated protein (dark red arrow) and halorhodopsin (gray arrows) inferred from this study (see results section) mapped onto a representation of the RpoB' reference tree from Figure 1. Branch lengths are extended by dashed lines, and the environmental fosmid FLAS10H9 (brown) is given an arbitrary position on the tree based on phylogenetic analyses on selected ORFs encoded on the genomic fragment. Those phylogenies (additional files 2 and 3) indicate that FLAS10H9 does not originate from a Clade II haloarchaeon, while some ORFs group with the genus Haloarcula. The bacteriorhodopsin and bac genes of FLAS10H9 (Figure 2a and 4) share affiliation with the Clade II haloarchaea, particularly Haloquadratum walsbyi. Given the limited amount of sequence data for the HR types, it is difficult to resolve the donor and recipient groups for transfer events that gave rise to the topology observed in Figure 2b