The genetic polymorphisms of TGFβ superfamily genes are associated with litter size in a Chinese indigenous sheep breed (Hu sheep)

Weimin Wang; Yongfu La; Xiang Zhou; Xiaoxue Zhang; Fadi Li; Bang Liu

doi:10.1016/j.anireprosci.2017.12.003

The genetic polymorphisms of TGFβ superfamily genes are associated with litter size in a Chinese indigenous sheep breed (Hu sheep)

Anim Reprod Sci. 2018 Feb:189:19-29. doi: 10.1016/j.anireprosci.2017.12.003. Epub 2017 Dec 16.

Authors

Weimin Wang¹, Yongfu La², Xiang Zhou³, Xiaoxue Zhang⁴, Fadi Li⁵, Bang Liu⁶

Affiliations

¹ Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China; College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
² College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
³ Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China.
⁴ College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; Engineering Laboratory of Sheep Breeding and Reproduction Biotechnology in Gansu Province, Minqin 733300, China.
⁵ College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; The State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; Engineering Laboratory of Sheep Breeding and Reproduction Biotechnology in Gansu Province, Minqin 733300, China.
⁶ Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: liubang@mail.hzau.edu.cn.

PMID: 29274749
DOI: 10.1016/j.anireprosci.2017.12.003

Abstract

Litter size, which is a complex economic trait in sheep, is affected by polygenes. Hu sheep are a prolific native breed in China and also an ideal resource for studying the genetic mechanism that controls litter size in sheep. In this study, we investigated the genetic effects of candidate genes on litter size in a large experimental population (n = 2021) of Hu sheep. A total of 23 single nucleotide polymorphisms (SNPs) including six reported major mutations (FecB, FecX^I, FecX^B, FecX^H, FecG^I, and FecG^H) and 17 novel SNPs in 10 candidate genes involved in reproduction were genotyped using KASPar technology. Genotyping showed that Hu sheep carry the FecB mutation, but not the FecX^I, FecX^B, FecX^H, FecG^H, and FecG^I mutations. Among the remaining 18 SNPs, 16 tagged SNPs were selected based on the HAPLOVIEW program. Analysis of single marker association indicated a significant association between litter size in Hu sheep and three mutations in the TGFβ superfamily (FecB, GDF9 and TGFBR2 genes). Quantitative trait modes (QTMs) analysis revealed that the FecB and GDF9 mutations exerted an additive effect, while the mutation located within TGFBR2 gene was dominant. Linear regression analysis of the association between multiple markers and litter size indicated a correlation between homozygous ewes with the GG/AA/TT genotype and larger litter size than any of the other genotypes. In conclusion, the FecB, GDF9, and TGFBR2 polymorphisms were implicated as genetic markers of potential importance in marker-assisted selection (MAS) strategies to improve litter size in Hu sheep.

Keywords: FecB; GDF9; Hu sheep; KASPar; Litter size; TGFBR2.

MeSH terms

Animals
China
Gene Expression Regulation / physiology
Genetic Markers
Genotype
Haplotypes
Litter Size / genetics*
Multigene Family / genetics*
Multigene Family / physiology
Polymorphism, Genetic*
Sheep / physiology*
Transforming Growth Factor beta / genetics*

Substances

Genetic Markers
Transforming Growth Factor beta