Single nucleotide polymorphisms in the growth hormone receptor gene and polymorphisms in the diacylglycerol acyltransferase 1 gene as related to meat production in sheep.

AIM

This study aimed to investigate the polymorphisms in genes related to meat production, including growth hormone receptor () and diacylglycerol acyltransferase 1 () genes, in different breeds of sheep, including Barki, Najdi, and Harri.

MATERIALS AND METHODS

Blood samples were collected from 75 randomly selected healthy Barki, Najdi, and Harri breeds of sheep, with 25 samples per breed. and genes were identified using a single nucleotide polymorphism assay followed by digestion with the restriction enzyme .

RESULTS

The analysis of the gene sequence showed nucleotide substitutions at nt 69 in exon 10 (c.69 G > A); this mutation is considered a transition mutation. The sequences of detected SNPs in the gene in the different sheep breeds were submitted to the GenBank database with accession numbers MG906773 to MG906781. The substitutions at exon 10 (c.69 G > A) results in an alteration to the amino acid (p. Lysine > Arginine). At c.69, the A allele frequency was 0.61, 0.59, and 0.54, while the G allele frequency was 0.39, 0.41, and 0.46, for Barki, Najdi, and Harri breeds, respectively. The genotype AG at nt 69 locus had the highest frequency in the Najdi and Harri sheep. The frequency of AG was 0.62, 0.61, and 0.64, while the frequency of AA was 0.30, 0.28, and 0.22, for Barki, Najdi, and Harri sheep, respectively. After digestion with the restriction enzyme , the locus had two genotypes, CC and CT. The highest frequency, 0.88, was found for allele C, which was detected in Barki breed. The lowest frequency, 0.75, for the same allele was found for Harri.

CONCLUSIONS

The detected CT genotype may explain the moderate intramuscular fat content and muscle marbling in the Barki sheep breed.