Figure 2
From: Differential gene transfers and gene duplications in primary and secondary endosymbioses
Scheme depicting an evolutionary hypothesis that explains genome locations of gro EL and cpn 60. An ancestral eubacterial-like gro EL duplicated in cyanobacteria to give two homologues: gro EL1 and gro EL2. Both copies were inherited by phototrophic eukaryotes. One of the copies, gro EL1, has been lost from the plastid genome in some lineages. gro EL2 was transferred into the cell nucleus and gave rise to cpn 60 in the case where gro EL1 is still maintained in the plastid genome, or into cpn60α and cpn 60β, where gro EL1 has been deleted. For details see text. P.D. = predicted.