Evolution of pcbd genes in vertebrates. (a) Maximum-likelihood phylogeny of Pcbd proteins based on 107 AA positions. The tree is rooted with Pcbd from sea urchin. Numbers at the branches denote bootstrap values (maximum likelihood/neighbor joining) above 50%. Pcbd was duplicated in vertebrates (Pcbd1 and Pcbd2). In Takifugu, two pcbd1 are observed in scaffolds 53 and 178. The latter (red) is a retro-pseudogene. (b) Exon-intron structure of Pcbd1. Pcbd1 from human and Takifugu scaffold 53 consists of four exons indicated by 4 blocks. Takifugu scaffold 178 contains a "processed" pseudogene with a single exon (bottom row) and a premature stop codon (arrowhead).