Polymorphism of diaclyglycerol acyltransferase 1 gene and its associations with milk traits in Bunaji, Rahaji and Bokoloji indigenous breeds of cattle in Nigeria

Abstract

The experiment was carried out to study the single nucleotide polymorphisms of diacylglycerol Acyltransferase 1 (DGAT1) gene and its association with milk traits among some selected indigenous breeds of cattle in Nigeria. Milk and blood samples were collected and analyzed from 60 lactating cows comprising 20 each of Rahaji, Bunaji (White Fulani) and Sokoto Gudali breeds of first parity and within their early lactation days (1-60). A reference sequel was downloaded from Ensembl while the DGAT1 sequences were cleaned and edited using Bioedit software. The DGAT1 sequences were aligned with reference sequences to identify the SNPs using clustal X hosted in Bioedit software. Genetic diversity indices were estimated using DNAsp software while allelic and genotypic frequencies were estimated by code written in R software. Discriminate principal component analysis (DAPC) was carried out in R software to classify the breeds based on the number of SNPs identified. The results of genetic diversity indices for three breeds of Nigerian Indigenous cattle revealed that Bokoloji, Rahaji and Bunaji had 4, 6 and 9 polymorphic informative sites respectively. The gene diversity showed Rahaji and Bunaji had 1.000 whereas Bokoloji had 0.900. The nucleotide diversity was low in Rahaji (0.0028) whereas high in Bunaji (0.0553) and Bokoloji (0.0167). White Fulani was found to have a higher variation of the DGAT1 gene among the breeds of cattle studied. It was recommended that further research should be carried out on gene expression analysis for milk traits to reveal other genes responsible for milk yield and composition.