Genome-wide identification and characterization of 14-3-3 genes in fishes

The 14-3-3 family genes are highly conserved regulatory factors in eukaryotes with involvement in multiple important cellular processes. However, detailed investigations of this family in fishes are very limited. Here, a comparative genomic and transcriptomic survey were performed to investigate the 14-3-3 family in fishes. We confirmed that the numbers of 14-3-3 genes ranged from 5 to 7 in non-teleost fishes, as well as additional 14-3-3 genes (9 to 11) in teleost fishes. In addition, some special teleost fishes possess 17 to 25 14-3-3s, which undergone the fourth whole-genome duplication (WGD). We also found that six pairs of fish 14-3-3 genes were clustered with mammalian epsilon, gamma, zeta, eta, tau and beta isotypes, respectively, while sigma was absent with a potential specificity within mammals, on the basis of their phylogenetic and synteny analyses. According to our results, we inferred that the diversity of 14-3-3 genes in fishes seems to be generated from a combination of WGD and gene loss. Comparative transcriptomic analysis revealed that there are differences in tissue distribution, and we speculated that 14-3-3 genes may contribute to terrestrial adaptations in mudskippers. In addition, protein sequence alignments of 14-33s supported their differential roles in fishes. In summary, our present comparative genomic and transcriptomic survey will benefit for further functional investigations of these fish genes.