Phylogenetic distribution of Pldi-Ak158810 loci and its surrounding genes within vertebrate species. The phylogenetic tree of 13 vertebrates was adapted from a widely accepted tree topology [5, 32]. The branch length does not represent the distance between each species and no molecular clock model was assumed. Different gene highlighted with marks of different colors. We could find the hits from Blastn in all mammals, whereas no hits in non-mammalian species. We could observe that all these 4 flanking protein are ordered laid around the Pldi-Ak158810 loci. In contrast, in non-mammalian species, some big gaps (larger than the average distance ~200 kb in mammals) inserted into the 4 flanking protein region, which made the order of the 4 proteins changed. The gap in Xenopus might due to the incomplete genomic description. Result of Blastn could be found in Additional File 6.