ASSOCIATION OF NEW SNPs AT DGAT1 GENE WITH MILK QUALITY IN EGYPTIAN ZARAIBI GOAT BREED

Mohamed, Shaimaa A.; Teleb, Doaa F.; Saad El-Deen, H.; Eid, Jehane I.; El-Ghor, Akmal A.

doi:10.21608/ejap.2022.245074

ASSOCIATION OF NEW SNPs AT DGAT1 GENE WITH MILK QUALITY IN EGYPTIAN ZARAIBI GOAT BREED

Document Type : Original Article

Authors

¹ Sheep & Goat Research Department, Animal Production Research Institute, 12611 Dokki, Giza, Egypt

² Camel Research Department, Animal Production Research Institute, 12611 Dokki, Giza, Egypt

³ Zoology Department, Faculty of Science, Cairo University, Giza 12613, Egypt

10.21608/ejap.2022.245074

Abstract

SUMMARY
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 of different electrophoresis patterns were sequenced and aligned with multiple sequence alignment tools (Clastal Omega and Jalview). Sequence analysis showed three new genotypes in the studied samples: the first was BB with C12T and G219A SNPs, the second DD contains C84T and G219A SNPs and the third was AG genotype with only G219A SNP. General Linear Model Analysis (GLM) showed that the DD genotype group with C84T and G219A SNPs had significantly the highest fat percent. Meanwhile, BB genotype group with C84T and G219A SNPs recorded significantly the highest total solids levels. On the other hand, the AG genotype group which has G219A SNP showed non-significant effect on milk components. Those new SNPs were submitted to GenBank and approved by accession number OM418856, OM418857 and OM418858 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. Substitution of Glycine (which is a small amino acid located on the surface of the protein) to Serine (which is larger than glycine) could lead to losses of several interactions with adjacent molecules in the protein structure.
In conclusion, the results demonstrated several genetic variations in DGAT1, which are associated with different milk composition, so it could be used as genetic markers for the selection of dairy goats in breeding programs to improve milk quality.

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