Investigation on the polymorphism of Beta-Casein gene (CSN2) in Kilis, Aleppo and Hair Goats by using allele specific PCR, Real-Time PCR and sequence analysis

The objective of this study was to investigate the genetic variability of Beta-casein gene (CSN2) with respect to certain nucleotides at the promotor region and exon 7 in Kilis, Aleppo and Hair goats by using allele specific polymerase chain reaction (AS-PCR), real-time PCR and sequencing methods. A total of 246 DNA samples were used. Presence of the mutation at the promotor region (g1311T>C) of CSN2 gene was searched by using AS-PCR, while the polymorphism at the 404th nucleotide of the exon 7 was analysed using Real-Time PCR and sequence analysis. By using AS-PCR frequency of the T allele at the 1311th nucleotide of the promotor region was found to be higher than that of C allele, while the frequency of the C allele was higher in Hair goats (0.0489) than that in Aleppo (0.0190) and Kilis goats (0.0188). When all three populations were considered, frequency of T nucleotide (CSN2C allele) at the 404th nucleotide position of the exon 7 (0.824) was higher than that of C nucleotide (0.176). The highest frequency of the CSN2C allele was found in Hair goats (0.8864) while the lowest frequency of this allele was in Kilis goats (0.6364). The results indicated that polymorphism was present with respect to g1311T>C mutation at the promotor region and at the 404th nucleotide of the exon 7 of the CSN2 gene among Kilis, Aleppo and Hair goats. Further studies are required for determining the effect of these polymorphism on the composition and beta-casein content the milk in these goat populations