Physical Meat Characteristics of Local Thin Tail Sheep based on Calpastatin (CAST) Genotype variation

Abstract

Calpastatin (CAST) is an indigenous inhibitor of calpain that involved in regulation of protein turn over and growth. The objective of this research was to identify genetic polymorphisms in the part of intron 5 - entire exon 6 of CAST gene in local sheep and their association with meat quality and muscle composition. A PCR-SSCP method was carried out to identify genetic variation of CAST gene. In total 401 heads of sheep from 8 subpopulations were investigated, three groups of samples were thin tail sheep from Sukabumi, Jonggol and Kissar. The rest samples were Priangan sheep from Margawati and Wanaraja and fat tail sheep from Donggala, Sumbawa and Rote islands. Twenty one heads from Jonggol were used for meat and muscle identification. SSCP analysis revealed that three different SSCP patterns corresponded to three different alleles in the CAST locus (CAST-1, 2 and 3 allele) with six different genotypes. Genetic variation between local sheep populations were calculated based on genotypic and allelic frequencies. Most populations studied were polymorphic, with genotype frequencies of CAST-11, CAST-12, CAST-22, CAST-13, CAST-23, and CAST-33 were 29.7%, 38.2%, 24.2%, 2.5%, 4.5% and 0.7% respectively. CAST-1 and 2 alleles were most commonly found in all populations with total frequency 95.8%, while rare allele was CAST-3 (4.2%) and only found in thin tail population. Based on sequence analysis identified a non-synonymous amino acid variation in exon 6 induced Gln/Leu substitusion. There was no association between CAST alleles and genotypes with meat quality.