Genetic basis of muscle-related traits in sheep: A review

Sheep is a major contributor to global food production among livestock and one of the great sources of red meat for human consumption. Several QTL and numerous genes with major and minor effects have been identified in association with the muscle characteristics in sheep breeds worldwide. Understanding the genetic background of growth and carcass-related traits in sheep is a major factor in increasing muscle growth, muscle hypertrophy and, eventually, meat production. This review concisely shows how major signaling pathways control skeletal muscle growth. Herein we aimed to discuss and summarize different research findings on genomic regions related to carcass traits and meat production in sheep. Several causative mutations with major effects on different muscle-related traits have been reported in various sheep breeds. A general overview of the studies on main candidate genes showed that some alleles have major phenotypic effects in different breeds with commercial and farm level usability. However, numerous genes with minor effects were also reported regarding the polygenic nature of muscle-related traits. The knowledge of the candidate genes involved in growth traits and their effects provides valuable information for breeding and selection of muscularity traits.