Polymorphism in Calpain gene of registered Brahman cattle from Mexico

Abstract

The present study was conducted to assess genotypic, allelic and haplotypic frequencies, in Brahman cattle in Mexico, of three single nucleotide polymorphism markers in the m -calpain gene, previously associated with beef tenderness in European, crossbred, and Zebu cattle (C316, C530, C4751).  Three allelic discrimination assays were designed for generation of the said frequencies.  The C316 marker showed a high frequency of the heterozygotic genotype (CG = 92%), and frequencies of these alleles were similar (54 and 46% for G and C, respectively).  By contrast, for C530, the main segregated genotype was the A alleles homozygote (98%).  For C4751, the heterozygotic genotype (CT) had the highest frequency (99%).  As to haplotypes, the most frequent compositions were GAT (50%) and CAC (45%).  These findings suggest that some favorable alleles for beef tenderness (C in 316 and C4751) are appreciably segregated in the Brahman population sampled. Thus, favorable homozygotic genotypes might be increased by integrated selection programs, including either the single marker or dual marker haplotype evaluation.  Further research is needed to determine relationships between meat quality traits (beef tenderness) and productive performance (current selection criteria), thus to promote consumption of Brahman beef and better position it in both national and international markets.