Association of new SNPs at DGAT1 gene with milk quality in Egyptian Zaraibi goat breed

This study aimed to detect putative genomic loci in candidate genes associated with milk composition in Egyptian Zaraibi goats. A total number of 50 samples were tested to detect polymorphism in exons 15 and 16 of the diacylglycerol acyltransferase 1 (DGAT1) gene. The PCR products were sequenced and aligned. Sequence analysis showed three new genotypes in the studied samples: T1C1 (T12C SNP), T2C2 (T84C), and AG (G219A), then three groups were created: the first group was BB with C1T1 and AG genotypes, the second was DD which contains C2T2 and AG genotypes, and the third was AG with only AG genotype. GLM showed that the DD group with C84T and G219A SNPs had significantly the highest fat percent. Meanwhile, the BB group with C84T and G219A SNPs recorded significantly the highest total solids levels. On the other hand, the AG group which has G219A SNP showed a non-significant effect on milk components. Those new SNPs were submitted to GenBank and approved to be published. Moreover, translation of those sequences showed that the G219A SNP causes a substitution of Glycine to Serine in exon 16 at position 106. This SNP (G106S) was predicted to be tolerated by SIFT with a score of 0.48.