Heat shock proteins (HSPs), members of molecular chaperones families fulfill essential roles under normal conditions and provide protection and adaptation during and after stress. Among different HSPs, HSP70 kDa family of proteins is most abundant and well-studied in human and mouse but has not yet been characterized in bovines. In silico analysis was performed to characterize members of HSP70 gene family in bovine genome and a total of 17 genes of bovine HSP70 gene family were identified. The members of HSP70 family were distributed over 12 chromosomes with gene size ranging from 1911 (HSPA2) to 54,017 bp (HSPA4). Five genes were intronless, while rest of 12 genes were multiexonic. Phylogenetic analysis of HSP70 gene family distinguished them into eight major evolutionary groups wherein members of group 1 were most divergent and quite dissimilar than from rest of the HSP70 sequences. Domain structure of all bovine HSP70 genes was conserved and three signature patterns HSP70_1, HSP70_2, and HSP70_3 were identified. HSPA8, HSP9, and HSPA1A showed comparatively higher expression in majority of tissues. Like humans, bovine HSP70 family was characterized by remarkable evolutionary diversity. The analysis also suggested resemblance of bovine HSP70 family to that of human compared to mouse. Overall, the study indicates the presence of diversity for structure, function, localization, and expression in the bovine HSP70 family chaperons which could form the basis to understand thermotolerance/adaptive changes in the bovines.
Keywords: Bovine genome; Expression; HSP70 gene family; In silico analysis; Phylogeny.