Genetic characterization, structural analysis, and detection of positive selection in small heat shock proteins of Cypriniformes and Clupeiformes

Abstract

In the current investigation, a total of 42 full-length, non-redundant small heat shock proteins (sHsps) were detected in Cyprinus carpio, Labeo rohita, Danio rerio, Salmo salar, Oncorhynchus mykiss, and Clupea harengus. The sHsps genes were classi ed into three groups based on phylogenetic analysis. All the sHsps were shown to have higher aliphatic index values, which is an indication that these proteins are more thermally stable. The hydrophilic nature of sHsps was deduced from the fact that all sh species had negative GRAVY scores. In all of the representative sh species, sHsps genes were assigned to distinct chromosomes in an inconsistent and unequal manner. Segmental duplications are the main events that have contributed to the expansion of the sHsps genes in all species. We were also able to determine the selective pressure that was placed on particular codons, and we discovered several signi cant coding sites within the coding region of sHsps. Eventually, diversifying positive selection was found to be connected with evolutionary changes in sHsps proteins, which shows that gene evolution controlled the sh adaption event in response to environmental conditions. Clari cation of the links between sHsps and environmental stress in sh will be achieved through rigorous genomic comparison, which will also yield substantial new insights.