Genome-wide analysis of the Aquaporin gene family in reptiles.

Aquaporin (AQP) genes are widely distributed in plants, unicellular organisms, invertebrates and vertebrates. They play a critical role in the transport of water and other solutes across cell membranes. AQP genes have been identified and studied in many species but the AQPs of reptiles are unknown. Newly obtained genome assemblies provide an opportunity to identify the complete AQPs set and explore the evolutionary relationship of these genes. A total of 212 putative AQP genes were identified from 18 reptile species, including 20 partial genes and 192 intact genes. Phylogenetic results showed that 193 AQP genes could be classified into three major clades according to their subfamily. The divergence or phylogenetic distance between reptile AQP genes was closely related to traditional taxonomic groupings. Evolutionary analysis indicated the presence of positively selected sites in the AQP3 (P = 0.0104⁎⁎) and AQP7 (P = 0.0202⁎⁎) among land reptiles, suggesting their relationship to terrestrial environment adaptation.