Molecular Characterization of TGF-Beta Gene Family in Buffalo to Identify Gene Duplication and Functional Mutations

The TGF-beta superfamily is ubiquitously distributed from invertebrates to vertebrates with diverse cellular functioning such as cell adhesion, motility, proliferation, apoptosis, and differentiation. The present study aimed to characterize the TGF-beta gene superfamily in buffalo through evolutionary, structural, and single nucleotide polymorphism (SNPs) analyses to find the functional effect of SNPs in selected genes. We detected 32 TGF-beta genes in buffalo genome and all TGF-beta proteins exhibited basic nature except INHA, INHBC, MSTN, BMP10, and GDF2, which showed acidic properties. According to aliphatic index, TGF-beta proteins were thermostable but unstable in nature. Except for GDF1 and AMH, TGF-beta proteins depicted hydrophilic nature. Moreover, all the detected buffalo TGF-beta genes showed evolutionary conserved nature. We also identified eight segmental and one tandem duplication event TGF-beta gene family in buffalo, and the ratio of Ka/Ks demonstrated that all the duplicated gene pairs were under selective pressure. Comparative amino acid analysis demonstrated higher variation in buffalo TGF-beta gene family, as a total of 160 amino acid variations in all the buffalo TGF-beta proteins were detected. Mutation analysis revealed that 13 mutations had an overall damaging effect that might have functional consequences on buffalo growth, folliculogenesis, or embryogenesis.