Analysis of genetic diversity at the PRLR gene in the Italian Mediterranean river buffalo and association study with milk fatty acid

Prolactin is an anterior pituitary peptide hormone involved in many different endocrine activities and is essential for reproductive performance. This action is mediated by its receptor. The prolactin receptor (PRLR) has been detected in various tissues including brain, ovary, placenta and uterus in several mammalian species. The prolactin receptor, encoded by the PRLR gene, is a member of the growth hormone/prolactin receptor gene family containing regions of identical sequencesA full characterisation of the river buffalo PRLR gene,amino acid sequences and genetic variabilty analysis is presented. The DNA regions of the PRLR gene spanning exons from 3 to 10 of ten Mediterranean river buffalo DNA samples were analysedand 13 exonic single nucleotide polymorphisms were found, 7 of which non-synonymousWe focused on the SNP g.11188A>G detected in exon 10 and responsible for the amino acid replacement p.His328>Arg. An association study between this detected polymorphism and milk fatty acids composition in Italian Mediterranean river buffalo was carried out. The fatty acid composition traits, fatty acid classes and fat percentage of 308 individual milk samples were determined. Associations between PRLR g.11188A>G genotype and milk fatty acids composition were tested using a mixed linear model. The PRLR AA genotype was found associated with higher contents of odd branched-chain fatty acids (OBCFA). The results of this study suggest that the PRLR AA animals might be useful in selection toward the improvement of milk fatty acid composition