Abstract
Despite the key role of casein genes and their effect on quantitative traits and technological assets of milk, few studies manipulated it in camels, unlike other ruminants. Thus, this investigation was performed to lighten up the genetic polymorphism of CSN2 and CSN3 genes, in Maghrebi camels, via PCR-SSCP and DNA sequencing tools, by measuring the impacted milk composition traits. Sixty-eight blood samples were collected from Maghrebi camels in Mersa Matrouh, Egypt. Also, 68 milk samples were collected at different stages of the lactation period. Protein, fat, lactose, total solid, and ash were estimated in all milk samples by biochemical methods. The results of the PCR-SSCP and the sequence analysis showed two genotypes (CC and CA) in CSN2 gene with one SNP (41 T > G) for CC genotype and two SNPs (41 T > G and 462A > C) for CA genotype, as showed three genotypes (AA, AT, and TT) in CSN3 gene with two SNPs (42C > A and 346 T > A) for AA genotype, two SNPs (42C > A and 100 C > T) for TT genotype, and four SNPs (42C > A, 100C > T, 238 T > G, and 346 T > A) for AT genotype. Allele C of CSN2 gene affected milk fat only at the first day and the first seven days of lactation period, while allele T of CSN3 gene affected both the studied milk composition initiated from the first seven days to the end of the lactation period. The genetic discrimination of the understudied genes may be utilized as a valuable marker in the selection of superior animals, through the favorable alleles and genotypes to improve the camel milk composition.