Genotyping analysis of milk protein genes in different goat breeds reared in Egypt [electronic resource].

Includes references.

The genes that encode the major protein and whey protein of milk are candidate genes in molecular marker assisted selection to improve the milk productivity in farm animals. Our study concerned with genotyping analysis of four milk gene, CSN1S1, CSN1S2. KCN and β-LG m four goat breed reared m Egypt; Baladi, Barki;, Damascus and zaraibi. Our results revealed that the CSN1S1 allelic variants in tested breeds showed five different genotypes, three of them were homozygous (A/A (4.5%), B/B (6.8%) and D/D (2.3%) and the other two were heterozygous (A/C (40.9%) and B/D (45.5%)). For CSN1S2 gene, the. Egyptian goat breeds carry the A,B and F alleles, while the C, D, E and 0 alleles were not present. The frequency of homozygous genotypes AA, BB were 28.9% and 26.7%. respectively, while heterozygous genotypes AB and AF were 40% and 4,4% respectively. The K-CN results illustrated that among different Egyptian breeds. B allele was the most common allele in breeds with maximum frequency in Zaraibi breed (90%). where the allele C with low frequncey in Barki (9.1%) and Zaraibi (8.3%) breed. Allele A was displayed in different frequencies ranged from 45.5% (Barki) to 10% (zaraibi). Genetic polymorphism of β-LG exon 7 showed two genetic variants S₁S₂, genotype with 45.5% and S₂S₂ with 54.5% The homozygous S₁S₁ genotype was not displayed in all tested animals. Among different breed,. the polymorphism within the proximal promoter region and exon 1 of β-LG displayed three genetic variants CC, TT and CT at different frequencies with the exception of CT which was at displayed In Zaraibi breed. In onclusion, genetic analysis of the goat milk protein genes is a valuable tool for seIecting the favorable genotype of milk genes with the highest yield of milk.

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