Significant improvements in animal performance, efficiency and carcass and meat quality have been made over the years through the application of standard animal breeding and selection techniques. However, such classical animal breeding techniques require several years of genetic evaluation of performance records on individual animals and their relatives and are therefore very expensive. Other efforts have been made to improve productivity and quality through the application of such management practices as the use of feed additives, animal hormonal implants and chemotherapeutics. However, there is significant political and regulatory resistance to the introduction and use of such methodologies. Such methodologies are also non-inheritable and need to be applied differently in every production system.
A method for identifying a bovine animal having a thinner subcutaneous fat depth (SFD), a lower skeletal muscle lipid accumulation (SMLA), a lower estimated stearoyl-CoA desaturase 16:1/16:0×100% value (R2), a lower estimated stearoyl-CoA desaturase 18:1/18:0×100% value (R3), a lower amount of beef fat monounsaturated fatty acids (MUFA), or a combination thereof.
In the present study, we targeted the ubiquinol-cytochrome c reductase core protein I (UQCRC1) gene, a nuclear-encoded component of mitochondrial complex III for its association with subcutaneous fat depth (SFD) and skeletal muscle lipid accumulation (SMLA) in Wagyu x Limousin F2 progeny. Four promoter polymorphisms were identified and genotyped on ~250 Wagyu x Limousin F2 progeny. Statistical analysis revealed that two completely linked polymorphic sites g.13487C>T and g.13709G>C )r2=1) were significantly associated with both SFD (P<0.01) and SMLA (P<0.0001). The difference between TTCC and CCGG haplotypes was 0.70 inches for SFD and 0.624 marbling scores for SMLA. Interestingly, the former haplotype produced higher promoter activities than the latter one by 43%-49% in three cell lines (P<0.05). In addition to Rett syndrome and breast/ovarian cancer observed in other studies, we report evidence for the first time that overexpression of UQCRC1 might affect mitochondrial morphology and/or physiology and lead to development of obesity and related conditions.