Comparative analysis of the tetraspanin gene family in six teleost fishes.

Tetraspanins are a family of membrane proteins, which play important roles in many aspects of cell biology and physiology via binding other tetraspanins or proteins. In this study, we identified 251 putative tetraspanin genes in 6 teleost fishes. Conserved gene organization and motif distribution suggested their functional relevance existing in each group. Synteny analyses implied conserved and dynamic evolution characteristics of this gene family in several vertebrates. We also found that some recombination events have accelerated the evolution of this gene family. Moreover, a few positive selection sites were identified. Expression patterns of some tetraspanins were further studied under organophosphorus stress using transcriptome sequencing. Functional network analyses identified some interacting genes that exhibited 174 interactions, which reflected the diversity of tetraspanin binding proteins. The results will provide a foundation for the further functional investigation of the tetraspanin genes in fishes.