Genetic characterization, structural and evolutionary adaptations of Small Heat shock proteins involved in mitigating environmental stress in Fishes

Abstract

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 classified 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 fish species had negative GRAVY scores. In all of the representative fish 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 significant 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 fish adaption event in response to environmental conditions. Clarification of the links between sHsps and environmental stress in fish will be achieved through rigorous genomic comparison, which will also yield substantial new insights.