Enhanced estimates of carcass and meat quality effects for polymorphisms in myostatin and µ-calpain genes1,2,3

Abstract

The objective of this study was to enhance estimates of additive, dominance, and epistatic effects of marker polymorphisms on beef carcass and quality traits. Myostatin (MSTN) F94L SNP and the µ-calpain (CAPN1) 316 and 4751 SNP haplotype have previously been associated with fat and muscle traits in beef cattle. Multiyear selection in a composite population segregating these polymorphisms increased minor allele (F94L L) and chosen haplotype (CAPN1 CC and GT) frequencies to intermediate levels resulting in more precise estimates of additive and nonadditive genetic effects. During the 3 yr after selection, 176 steers were evaluated for growth, carcass, meat quality, tenderness (n = 103), and meat color traits. The statistical model included year, age of dam, age of the steer, and genotype in a random animal model. The 9 genotypes (3 CAPN1 diplotypes × 3 F94L genotypes) affected marbling score, ribeye area, adjusted fat thickness, vision yield grade (all P < 0.001), slice shear force (P = 0.03), and CIE L* reflectance (P = 0.01). Linear contrasts of the 9 genotypes estimated additive, recessive, and epistatic genetic effects. Significant additive effects of the F94L L allele decreased marbling score, adjusted fat thickness, vision yield grade, and slice shear force; and increased ribeye area and CIE L* reflectance. The homozygous F94L FF and LL genotypes differed by 1.3 to 1.9 phenotypic SD for most carcass traits and by 0.8 to 0.9 SD for slice shear force and CIE L* reflectance but carcass weight differed by only 3 kg (0.1 SD). The L allele was partially recessive to F for ribeye area (P = 0.02) and the heterozygous FL means tended to be closer to the FF genotype than the LL genotype for other carcass traits but differences from additive were not significant. The CAPN1 additive × F94L additive effect on slice shear force was the only significant epistatic estimate. The F94L L allele is prevalent in Limousin but nearly absent in other U.S. purebreds. This allele had about half of the effects on birth weight, muscle, and fat traits reported for severe MSTN mutations in Belgian Blue and Piedmontese breeds. The interaction between MSTN and CAPN1 genotypes may reflect the strong additive effects of MSTN F94L L allele on fat and muscle traits interfering with the phenotypic effect of CAPN1 genotype on meat tenderness.

Using Genomics to Measure Phenomics: Repeatability of Bull Prolificacy in Multiple-Bull Pastures

“…Estimated bull prolificacy could be used as phenotypic data for genomic evaluation with information transfer to breeding value prediction organizations based on careful documentation of commercial bulls, their use in pastures, and their genotypes. Claims-based marketing programs could be verified for things such as breed composition or genetic potential based on markers associated with large effects for carcass traits, e.g., beef tenderness [20] or carcass leanness [21]. A pool including heifers could be genetically evaluated for reproductive traits, e.g., pubertal age, antral follicle count, and heifer pregnancy rate [22,23], and for common genetic disorders [24] or disease susceptibility to avoid inappropriate matings.…”

Using Genomics to Measure Phenomics: Repeatability of Bull Prolificacy in Multiple-bull Pastures

“…Estimated bull prolificacy could be used as phenotypic data for genomic evaluation with information transfer to breeding value prediction organizations based on careful documentation of commercial bulls, their use in pastures, and their genotypes. Claims-based marketing programs could be verified for things like breed composition or genetic potential based on markers associated with large effects for carcass traits, e.g., beef tenderness [20] or carcass leanness [21]. A pool including heifers could be genetically evaluated for reproductive traits, e.g., pubertal age, antral follicle count, and heifer pregnancy rate [22,23], and for common genetic disorders [24] or disease susceptibility to avoid inappropriate matings.…”

Genetic Diversity Identification and Haplotype Distribution of Myostatin Gene in Goats

“…F94L mutants are found in MSTN of Limousin cattle, Angus cattle and a hybrid of these two and the birth weights of these mutant individuals increase by 2.7%, 2.2% and 3.2%, respectively, compared with those of wild-type individuals (Lee et al 2019). F94 sites influence the marbling score, eye muscle area and fat thickness of cattle (Bennett et al 2019). Knocking out MSTN via gene editing techniques can lead to skeletal muscle hypertrophy, whereas overexpressing it can cause muscle atrophy (Wang et al 2018;Guo et al 2016;Rodriguez et al 2014).…”