Effect of Myostatin (MSTN) g+6223G>A on Production and Carcass Traits in New Zealand Romney Sheep

Abstract

Myostatin, which is also known as growth and differentiation factor 8 (GDF8), has been reported to act as a negative regulator of skeletal muscle development. Variation in the myostatin gene (MSTN) has been associated with variation in muscularity in certain meaty sheep breeds. Polymerase Chain Reaction-Single Strand Conformational Polymorphism (PCR-SSCP) analysis was used to investigate allelic variation in the previously described g+6223G>A single-nucleotide polymorphism (SNP) in the 3' untranslated region (3'UTR) of MSTN. The sheep studied were 79 New Zealand (NZ) Romney lambs derived from a single sire heterozyous for g+6223G>A, which is in itself notable as this polymorphism has not been described previously in this breed. Allelic variation was observed to be associated with an abnormal gender ratio (p = 0.046) in the progeny. The presence of allele A was observed to have an effect (p<0.05) on birth weight, mean loin yield, proportion yield loin and total muscle yield. Allelic variation did not significantly affect mean shoulder yield, leg yield, proportion yield shoulder and proportion yield leg. This preliminary result suggests that while the A allele at MSTN g+6223 appears to improve some valuable traits in NZ Romney sheep, further research is required to understand if and how it may affect other traits.