Identification of novel polymorphism in mammary-derived growth inhibitor gene of water buffalo and its expression analysis in the mammary gland.

Mammary-derived growth inhibitor (MDGI), a member of the lipophilic family of fatty acid-binding proteins, plays an important role in the development, regulation, and differentiation of the mammary gland. The aim of the study was to identify polymorphism in the gene and its expression analysis in the mammary gland at various stages of lactation, in Indian buffalo. Nucleotide sequence analysis of gene in different breeds of riverine and swamp buffaloes revealed a total of 16 polymorphic sites and one . Different transcription factor binding sites were predicted for buffalo gene promoter sequence, using online tools and analysis indicating that the SNPs in this region can impact the gene expression regulation. Phylogenetic analysis exhibited the of buffalo being closer to other ruminants like cattle, yak, sheep, and goats. Further, the expression analysis revealed that buffalo being highly expressed in well-developed mammary glands of lactating buffalo as compared to involution/non-lactating and before functional development to start the milk production stage in heifers. Stage-specific variation in expression levels signifies the important functional role of the gene in mammary gland development and milk production in buffalo, an important dairy species in Southeast Asia.