Consequences of Lineage-Specific Gene Loss on Functional Evolution of Surviving Paralogs: ALDH1A and Retinoic Acid Signaling in Vertebrate Genomes
Figure 1
Phylogenetic tree of the vertebrate Aldh1A gene family.
All phylogenetic methodologies (Bayesian, Maximum-likelihood, Neighbor-joining and Maximum-parsimony; included in Figure S1) agreed on a unique gene topology in which Aldh1a1 (green background) and Aldh1a2 (tan background) are the closest sister clades, while Aldh1a3 (blue background) diverged basally: ((Aldh1a1, Aldh1a2), Aldh1a3). Values at nodes correspond to the posterior probabilities inferred from the Bayesian method and generally show a highly supported tree topology. The only exception is a moderately high value of 0.76 for the Aldh1a1-Aldh1a2 node (for this node, the ML, NJ and MP supporting values are also shown). While Aldh1a2 and Aldh1a3 are present in both tetrapods (red lines) and teleosts (blue lines), Aldh1a1 is absent from teleost genomes. Scale bar indicates amino-acid substitutions. Tetrapods: Hs, Homo sapiens; Mm, Mus musculus; Rn, Rattus novergicus; Gg, Gallus gallus; Xt, Xenopus tropicalis; Teleosts: Dr, Danio rerio; Ga, Gasterosteus aculeatus; Ol, Oryzias latipes; Tn, Tetraodon nigroviridis; Tr, Takifugu rubripes; Cephalochordates: Bf, Branchiostoma floridae.