Genomic approaches to economic trait loci and tissue expression profiling: application to muscle biochemistry and beef quality.

Genetic and environmental factors profoundly alter the phenotypes of animals. Nowadays, genomics allows large-scale analysis of gene characteristics (structural genomics) and expression (functional genomics). Genome mapping, comparative genomics and identification of quantitative trait loci and polymorphisms are the subject of active investigation to gain a better knowledge of the structure and function of genes. Gene expression profiling using DNA microarrays and proteomics holds great promise for the study of regulatory events which control the final biological functions. Combined with classical genetics and muscle biochemistry to form an integrative biology, these new approaches will bring a better understanding of complex traits and physiological processes. Major applications in meat science could be, for cattle, (1) the identification of new predictors of quality traits (for instance, tenderness), (2) the monitoring of beef quality (including traceability) through the production systems (nutrition level, growth path, grass-feeding), and (3) the improvement of animal selection (markers and gene assisted selection) which may also include quality traits.