Effects of Intronic SNPs in the Myostatin Gene on Growth and Carcass Traits in Colored Polish Merino Sheep.

Ewa Grochowska,Bronisław Borys,Sławomir Mroczkowski

doi:10.3390/genes11010002

Abstract

Myostatin acts as a negative regulator of muscle growth; therefore, its role is important with regard to animal growth and meat production. This study was undertaken with the objective to detect polymorphisms in the first intron and c.*1232 position of the MSTN gene and to analyze effects of the detected alleles/genotypes on growth and carcass traits in Colored Polish Merino sheep. In total, 23 traits were analyzed, i.e., seven describing lamb growth and 16 carcass traits. Single nucleotide polymorphisms (SNPs) in the first intron and the c.*1232 position were identified using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods, respectively. The MIXED procedure of the SAS software package was used to analyze allelic and genotypic effects of the MSTN gene on growth and carcass traits. Polymorphisms were only detected in the first intron of the MSTN gene. All investigated sheep were monomorphic G in the c.*1232 position. The MSTN genotype was found to have significant effect on body weight at 2nd day of life (BW2) and loin and fore shank weights. Significant allelic effects were detected with respect to BW2, scrag, leg, fore, and hind shank weights. These results suggest that polymorphisms in the first intron of the MSTN gene are relevant with respect to several carcass traits and BW2 in Colored Polish Merino sheep.

Highlights

Constant improvement of lamb growth and meat yield of lamb carcasses is of high interest for sheep breeders due to direct benefits from breeding of faster growing animals with higher final body weight as well as carcass weight
These results suggest that the negative effect of the myostatin gene (MSTN)-A allele on leg weigh or yield could be similar in different sheep breeds raised in divergent environments, what may drove to conclusion that, with respect to this trait, genetic effect could be more relevant than environment
Polymorphisms in the MSTN gene are associated with increased muscle mass and decreased fatness [13,15]; we regarded this gene as genetic marker in selecting for better meat performance in Merino lambs

Summary

Introduction

Constant improvement of lamb growth and meat yield of lamb carcasses is of high interest for sheep breeders due to direct benefits from breeding of faster growing animals with higher final body weight as well as carcass weight. One of them is a marker-assisted selection, which seems to be convenient choice, especially for less numerous indigenous sheep populations. This relatively cheap approach has a potential to increase rates of genetic gain for certain growth and carcass traits in different sheep populations. Myostatin, being a member of the transforming growth factor-β super-family, acts as a negative regulator of muscle growth. This protein is a homodimer, which is primary synthesized in skeletal muscle as a 375-amino acid propeptide. This propeptide is proteolytically processed at the RSRR (263) site to give rise to a 26-kDa active processed peptide, which binds to receptor to elicit biological function [1,2]

Methods

Results

Discussion

Conclusion