Fig. 7

PPAR subfunctionalization of the fabp1 promoters following the teleost whole genome duplication. An ancestral fabp1 promoter contained two PPREs that had high sequence identity to the consensus sequence for PPREs. These PPREs were retained in the spotted gar fabp1 gene promoter. In zebrafish, fabp1a and the ancestral fabp1b underwent subfunctionalization. fabp1a retained the PPARα-selective PPRE and fabp1b retained the PPARγ-selective PPRE, following whole genome duplication. Further subfunctionalization of promoter function occurred following the tandem gene duplication of zebrafish fabp1b resulting in fabp1b.1 and fabp1b.2. Passage of time and accumulation of mutations is represented from left to right. PPREs are represented by purple (1, α) or red (2, γ) rectangles. PPRE loss is represented by smaller, more transparent rectangles. zf, zebrafish; sg, spotted gar; WGD, whole genome duplication; TGD, tandem gene duplication