Comparative Analysis of the Gene Family in 12 Fish Species.

Aquaporins (Aqps) are a class of water channel proteins that play key roles in many physiological functions and cellular processes. Here, we analyzed 166 putative genes in 12 fish species and divided them into four groups. Gene organization and motif distribution analyses suggested potentially conserved functions in each group. Several recombination events were identified in some members, which accelerate their divergence in evolution. Furthermore, a few positive selection sites were identified, and mutations at these sites could alter the stability of Aqp proteins. In addition, expression profiles of some genes under pathogen infection and organophosphorus pesticide stress were also investigated. The result implied that several genes may affect different immune responses and osmoregulation. This study provides a comparative analysis of the fish gene family to facilitate further functional analyses.