Comparative transcriptomic profile for meat tenderness in multibreed cattle raised in tropical environments

Abstract

Heat stress can compromise the physiology of several important traits in animals raised in tropical areas. One approach to mitigate the heat stress effect is to investigate introgression from thermotolerant breeds into more thermally sensitive breeds through crossbreeding. Researchers from the Department of Animal Science from the University of Florida has been evaluating several traits of interest in multi breed beef cattle of Brahman and Angus obtained by diallel mating system. In this context, the project aims to evaluate the transcriptome differences in the Longissimus dorsi (LD) muscle of Nellore cattle, crossbred Nellore-Angus (1/2), Brahman, Brahman-Angus (1/2) and Angus, associated with meat tenderness. LD muscle samples from each biological type were evaluated. The transcriptomic profile of mRNA were performed using the large-scale RNA sequencing technique in Brazil and in the USA Laboratories. For each one of the five genotypic composition groups, eight animals with higher Shear force values (HSF) and eight with lower Shear force values (LSF) will be evaluated. This strategy will allow two comparisons: comparison of animals "between" and "within" of the different genotypic combinations. We expect to identify potential causal genes, metabolic pathways, biological processes, and transcription regulatory factors associated with meat tenderness in order to understand the molecular differences between Bos taurus indicus, Bos taurus taurus and crossbreed cattle. This will increase our knowledge about the factors that regulate gene expression and that can influence the meat tenderness which will contribute to genetic breeding programs.