Segregation of polymorphisms in μ-calpain and calpastatin in beef cattle in Puerto Rico

Abstract

The distribution of single nucleotide polymorphisms (SNP) in two regions of Calpain (CAPN1-316 and CAPN1-4751) and a SNP in Calpastatin (CAST) was determined in beef cattle raised in Puerto Rico (n=271). Genotypic and allelic frequencies were determined for each SNP in Senepol (n=53), Charolais (n=49), Angus (n=27), Charbray (n=38), Brahman (n=16), Zebu (n=16) and crossbred bulls (n=72). For CAPN1-ZAB, the global genotypic frequencies (n=219) were 0.07/CC (n=15), 0.38/CG (n=83) and 0.55/GG (n=121) with allelic frequencies of 0.21/C and 0.74/G. The CC genotype was absent in Charbray, Charoláis, Angus, Zebu and Brahman bulls. In Charolais, Zebu, Brahman and Charbray the GG genotype was in greater proportion than CG, while the inverse was observed in the Senepol breed. In Angus and crossbred animals, the CG and GG genotype were found in equal distribution. The global genotypic frequencies for CAPN1-4751 (n=256) were 0.17/CC (n=44), 0.45/CT (n=114) and 0.38/TT (n=98). The allelic frequencies were 0.39/C and 0.61/T. Animals inheriting the CT genotype were more frequent in Charolais, Senepol, Angus and crossbred bulls, while the TT was more common in Charbray and Brahman. For CAST, the global genotypic frequencies (n=261) were 0.04/CC (n=10), 0.26/CT (n=68), and 0.70/TT (n=183), respectively. The global allelic frequencies were 0.17/C and 0.83/T. The CC genotype was not found in Charoláis, Angus and Brahman breeds. The TT animals were more frequent in all breeds, as well as in the crossbred population. The segregation of polymorphisms in CAPN1 and CAST could potentially be associated with differences in economically important traits for Puerto Rican beef cattle, but this possibility should be evaluated by genotyping a broad range of animals with detailed phenotypic data before incorporating these SNP into markerassisted selection programs.