Polymorphism Detection of GDF9 Gene and Its Association with Litter Size in Luzhong Mutton Sheep (Ovis aries).

Fengyan Wang,Lin Tao,Linxiang Pan,Xiangyu Wang,Ran Di,Yongfu La,Lin Ma,Rensen Zhang,Xiaoyun He,Mingxing Chu

doi:10.3390/ani11020571

Abstract

Simple SummaryGDF9 and BMPR1B are two important reproduction genes. In this study, the whole coding region of GDF9 was sequenced, of which the mutations were detected in Luzhong mutton sheep. The results suggested that two single nucleotide polymorphisms (SNPs), g.41768501A > G and g.41768485 G > A in GDF9 gene were associated with litter size. The g.41768485 G > A is a missense mutation which is predicted to affect the tertiary structure of the protein. Thus, these two mutations may be potential effective genetic markers to improve the litter size in sheep.Litter size is one of the most important economic traits in sheep. GDF9 and BMPR1B are major genes affecting the litter size of sheep. In this study, the whole coding region of GDF9 was sequenced and all the SNPs (single nucleotide polymorphisms) were determined in Luzhong mutton ewes. The FecB mutation was genotyped using the Sequenom MassARRAY®SNP assay technology. Then, the association analyses between polymorphic loci of GDF9 gene, FecB, and litter size were performed using a general linear model procedure. The results showed that eight SNPs were detected in GDF9 of Luzhong mutton sheep, including one novel mutation (g.41769606 T > G). The g.41768501A > G, g.41768485 G > A in GDF9 and FecB were significantly associated with litter size in Luzhong mutton ewes. The g.41768485 G > A is a missense mutation in the mature GDF9 protein region and is predicted to affect the tertiary structure of the protein. The results preliminarily demonstrated that GDF9 was a major gene affecting the fecundity of Luzhong mutton sheep and the two loci g.41768501A > G and g.41768485 G > A may be potential genetic markers for improving litter size.

Highlights

To determine the polymorphism of growth differentiation factor 9 (GDF9) gene in Luzhong sheep with different litter sizes, the entire coding sequence of GDF9 gene in 154 ewes were sequenced. By comparing their coding sequence with the known sequence of GDF9 gene in Rambouillet sheep (GenBank NC_040256.1), eight mutation loci were identified in the GDF9 gene, of which one mutation
The GDF9 gene coding sequence in Luzhong mutton sheep was shown in File S1
The present study identified eight SNPs, including one novel mutation in the GDF9 gene of Luzhong sheep

Summary

Introduction

Litter size is one of the most important economic traits and is closely related to the economic benefits of modern sheep farming. The growth differentiation factor 9 (GDF9) gene, encoding one member of the transforming growth factor β (TGF-β) superfamily, has important functions in the reproduction of ewes [1]. Many mutations in the gene were identified in Belclare sheep (FecGF ) [4] of Europe, Iranian Afshari sheep (G2, G3, and G4) [5] and Fat-Tailed sheep (G1, G2, G3, and G4) [6] of Middle Eastern origin, and Rahmani sheep (FecGH ) [7] of Africa. It was reported that c.978A>G and c.994G>A, FecGH , c.1040T>C (Phe 347 Ser) were associated with litter size in Araucana creole, Rahmani, and Mongolia sheep [7,8,9], respectively

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