The Identification of Mutation in BMP15 Gene Associated with Litter Size in Xinjiang Cele Black Sheep.

Zhi-Gang Niu,Sen Tang,Xiang-Dong Ding,Hong-Cai Shi,Jin Qin,Yu-Gong Ding,Yao Jiang

doi:10.3390/ani11030668

Abstract

Simple SummaryThe gene for Bone Morphogenetic Protein 15 has multiple single-nucleotide polymorphism sites related to fertility in sheep. To increase fertility, a better understanding of the regulation of Bone Morphogenetic Protein 15 in sheep is essential. This work describes the phenotype and molecular characteristics of a mutation identified in the Bone Morphogenetic Protein 15 gene of Cele black sheep in Xinjiang, China. This mutation may affect the fertility of sheep, which is very useful for breeding purposes.The Bone Morphogenetic Protein 15 (BMP15) gene is known to have multiple single-nucleotide polymorphism sites associated with sheep fecundity. This study used gene sequence analysis and mutation detection assays for BMP15 by using 205 blood samples of ewes with known lambing records. Sequence analysis showed that mutation B1 missed the CTT base in exon 1 at positions 28–30, leading to a leucine deletion in the BMP15 protein. Litter size of ewes differed significantly between BB and B+ genotypes of B1 (p < 0.05); however, the differences between wild genotype (++) and homozygous (BB) or wild genotype (++) and heterozygous (B+) were not significant (p > 0.05). Another mutation, T755C, is a T-to-C base change at position 755 of exon 2, resulting in leucine replacement by proline at this position of the BMP15 protein (p.L252P). Two genotypes were identified in the flock: heterozygous (E+) and wild-type genotype (++). Ewes with heterozygous (E+) p.L252P had significantly larger litter sizes than those with the wild-type genotype (p < 0.05). Comprehensive analysis suggests that p.L252P is a mutation that affects fecundity in Cele black sheep.

Highlights

Cele black sheep are a prolific sheep breed in Xinjiang, China
We previously identified mutations in FecB of the bone morphogenetic protein receptor type IB (BMPR-IB) gene associated with increased litter sizes in Cele black sheep
This study showed that heterozygous (E+) ewes have larger litter sizes than wild-type (++) ewes (p < 0.05), suggesting that this mutation may have influenced the litter size by a change in the structure and function of the Bone Morphogenetic Protein 15 (BMP15) protein

Summary

Introduction

Cele black sheep are a prolific sheep breed in Xinjiang, China. This breed produces more lambs per litter and has more estrous cycles within a year than other breeds in the same area. The environment of Xinjiang is very harsh, with hot summers, cold winters, and windy as well as dry conditions all year round, ewes of this breed produce. Substantial progress has been made in the understanding of major genes for the prolificacy of sheep throughout the world. A number of studies showed that major genes offer the potential to significantly increase the reproductive performance of sheep flocks [1,2,3]. The following three classes of fecundity genes (Fec) have been identified in sheep: bone morphogenetic protein receptor type IB (BMPR-IB), known as FecB on chromosome 6, growth differentiation factor 9 (GDF9), known as FecG on chromosome

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