Genetic diversity of kappa-casein gene in Raini Cashmere, Saanen and Wild goats using PCR-RFLP

Milk has long been considered as a complete food supply and supplying part of the daily nutritional needs of humans. Kappa casein has the most important role in stability of casein micelles, size and their specific function among the milk proteins. Also it has an important role in the quality of the produced cheese and speed cottage and the process of changing milk to cheese. Hence, the purpose of this study was to investigate polymorphism in the exon 4 gene of CSN3 using the PCR-RFLP technique. For this purpose, blood samples were taken from 75 goats (Sannan, Raini and wild breeds), and genomic DNA was extracted. The polymerase chain reaction (PCR) was performed for amplification of exon 4 on CSN3 gene with a length of 645bp using a pair of specific primer. PCR productions were separated using agarose gel and it was found that the intended fragment was amplified well. The amplified fragment was digested with HaeIII enzyme and determining the genotype was performed on the 2% agarose. The result of studies carried out on the goat breeds indicated that the population was monomorphic for the kappa casein gene. Lack of the polymorphism, can be because of no mating with others goat breeds, the closed breeding place and small sample size probably, therefore, next studies on more number of these animals should aim to determine crucial relationship between kappa casein genotypes and maternal characteristics, as selection could be enhanced by the inclusion of genetic markers in breeding decisions.