Impact of two myostatin (MSTN) mutations on weight gain and lamb carcass classification in Norwegian White Sheep (Ovis aries)

Inger A Boman,Gunnar Klemetsdal,Thor Blichfeldt,Dag I Våge,Ola Nafstad

doi:10.1186/1297-9686-42-4

Inger A Boman, Gunnar Klemetsdal + Show 3 more

Open Access

https://doi.org/10.1186/1297-9686-42-4

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Abstract

BackgroundOur aim was to estimate the effect of two myostatin (MSTN) mutations in Norwegian White Sheep, one of which is close to fixation in the Texel breed.MethodsThe impact of two known MSTN mutations was examined in a field experiment with Norwegian White Sheep. The joint effect of the two MSTN mutations on live weight gain and weaning weight was studied on 644 lambs. Carcass weight gain from birth to slaughter, carcass weight, carcass conformation and carcass fat classes were calculated in a subset of 508 lambs. All analyses were carried out with a univariate linear animal model.ResultsThe most significant impact of both mutations was on conformation and fat classes. The largest difference between the genotype groups was between the wild type for both mutations and the homozygotes for the c.960delG mutation. Compared to the wild types, these mutants obtained a conformation score 5.1 classes higher and a fat score 3.0 classes lower, both on a 15-point scale.ConclusionsBoth mutations reduced fatness and increased muscle mass, although the effect of the frameshift mutation (c.960delG) was more important as compared to the 3'-UTR mutation (c.2360G>A). Lambs homozygous for the c.960delG mutation grew more slowly than those with other MSTN genotypes, but had the least fat and the largest muscle mass. Only c.960delG showed dominance effects.

Highlights

Our aim was to estimate the effect of two myostatin (MSTN) mutations in Norwegian White Sheep, one of which is close to fixation in the Texel breed
In Norwegian White Sheep (NWS), two myostatin (MSTN) mutations affecting conformation and fat classes are segregating: the 3’-UTR mutation creating an illegitimate microRNA site (c.2360G>A) that was identified in Texel sheep [1] and a frameshift mutation explained by a deletion of one base pair in nucleotide position 960 (c.960delG), identified in NWS [2]
The number of homozygous c.960delG ewes was low (Table 1), and their progeny were omitted from the analysis

Summary

Introduction

Our aim was to estimate the effect of two myostatin (MSTN) mutations in Norwegian White Sheep, one of which is close to fixation in the Texel breed. In Norwegian White Sheep (NWS), two myostatin (MSTN) mutations affecting conformation and fat classes are segregating: the 3’-UTR mutation creating an illegitimate microRNA site (c.2360G>A) that was identified in Texel sheep [1] and a frameshift mutation explained by a deletion of one base pair in nucleotide position 960 (c.960delG), identified in NWS [2]. The aim of the current study was to investigate the effect of the c.960delG mutation on growth and carcass traits in NWS under ordinary commercial management conditions. Since the Texel breed is one of the NWS founder breeds [3,4], the ongoing study was expanded in order to include this new mutation. We present data on how the two mutations affect weight gain and lamb carcass classification

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