Study on candidate gene for fecundity traits in Xingjiang Cele black sheep

Abstract

The aim of the present study is to find a potential candidate gene for high fecundity in Cele black sheep. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology was used to detect single nuclear polymorphism (SNP) of four candidate genes (BMPR-IB, BMP15, GDF9, and ESRα) in Cele black sheep. The results showed that (i) A-G mutation was found at 746 bp in BMPR-IB in which the frequencies of homozygote (BB), heterozygote (B+) and wild type (++) were 0.113, 0.471, and 0.416, respectively. Significant differences were observed in litter size between ++ and B+ (P < 0.01) and between ++ and BB of individuals (P < 0.05). (ii) C-G mutation was found at exon 1 of ESRα in which the frequencies of homozygote, heterozygote and wild type were 0.047, 0.321 and 0.631, respectively. No significant difference was observed in litter size among the genotypes of ESRα (P > 0.05). (iii) No polymorphism was found in four mutation sites (FecX^G, FecX^B, FecX^I, FecX^H) of BMP15 and in one mutation site (FecG^H) of GDF9 gene. The results indicate that fecundity characteristic was positively correlated to BMPR-IB. However, there was no relation between fecundity characteristic and detected SNP sites of ESRα, BMP15 and GDF9 genes. These preliminary results showed that the BMPR-IB gene is either a major gene that influences the prolificacy in Cele black sheep or a molecular genetic marker in close linkage with such a gene.

Key words: Cele black sheep, fecundity candidate gene, BMPR-IB, BMP15, GDF9, ESRα.