A COMPARATIVE ANALYSIS OF GOAT αS1-CASEIN LOCUS AT PROTEIN AND DNA LEVELS IN CARPATHIAN GOAT BREED

Abstract

Since the discovery of four alleles categories in goat αS1-casein locus, associated with different synthesis levels, goat milk protein polymorphisms received a considerable research interest (Mahe et. al., 1993). Genotyping in goat αS1-casein locus became an important tool for improving goat milk quality and its manufacturing properties, in different breeds. In Romania, Carpathian goat breed was never submitted to an intense breeding process and therefore exhibits a high heterogeneity concerning milk quality. We already reported a high degree of αS1-casein polymorphisms in this breed (Balteanu et al., 2007), but genotyping of bucks it was not possible so far due to the lack of an available DNA test in our country. To set up a PCR test 18 Carpathian goat females, previously genotyped through isoelectric focusing (IEF) with AA, EE, FF, AE, AF, EF genotypes, were chosen. DNA was extracted from collected blood samples. PCR reaction was performed as described by Ramunno et al. (2000), with the following modifications: 35 cycles: 94°C/1’, 60°C/1’, 72 °C/ 1’; 1 cycle 72°C/7’, using SYBR Green Supermix (BioRad). Amplified products were digested with XmnI enzyme and migrated in 4 % agarose, stained with SYBR Safe (Fig. 1). Our results obtained by PCR-RFLP analysis confirmed the genotypes observed at the protein level on the same individuals by IEF (Balteanu V.A. et. al., 2007). This genotyping method will be used in the near future for genotyping kids, young females and bucks used for reproduction, in order to improve milk quality in Carpathian Goat breed.