Expression Analysis of the Prolific Candidate Genes, BMPR1B, BMP15, and GDF9 in Small Tail Han Ewes with Three Fecundity (FecB Gene) Genotypes

Abstract

The expression characteristics of the prolific candidate genes, BMPR1B, BMP15, and GDF9, in the major visceral organs and hypothalamic–pituitary–gonadal (HPG) axis tissues of three FecB genotypes (FecB BB, FecB B+, and FecB ++) were explored in STH ewes using RT-PCR and qPCR. The results were as follows, BMPR1B was expressed in all FecB BB genotype (Han BB) tissues, and GDF9 was expressed in all selected tissues, but BMP15 was specifically expressed in the ovaries. Further study of ovarian expression indicated that there was no difference in BMPR1B expression between genotypes, but the FecB B+ genotype (Han B+) had greater expression of GDF9 and BMP15 than Han BB and FecB ++ genotype (Han ++) (p < 0.05, p < 0.01). BMP15 expression was lower in the ovaries of Han BB than in Han ++ sheep, but the reverse was shown for GDF9. The gene expression in non-ovarian tissues was also different between genotypes. Therefore, we consider that the three genes have an important function in ovine follicular development and maturation. This is the first systematic analysis of the tissue expression pattern of BMPR1B, BMP15, and GDF9 genes in STH sheep of the three FecB genotypes. These results contribute to the understanding of the molecular regulatory mechanism for ovine reproduction.