Expression analysis of BMPR1B, BMP15, and GDF9 in prolific and non-prolific sheep breeds during the follicular phase

Abstract

To elucidate how expression characteristics of BMPR1B, BMP15, and GDF9 are associated with sheep reproduction, tissue-specific mRNA expression of these genes in Small Tail Han (STH) ewes (a polytocous breed) and Sunite (SNT) ewes (a monotocous breed) in the follicular phase were investigated using transcription profiling and quantitative real-time PCR (qPCR). Expression levels of the three genes were all highest in ovaries of the two sheep breeds, and BMPR1B and GDF9 expression in the ovarian tissue was significantly higher in STH sheep compared with SNT sheep (P < 0.01), whereas BMP15 expression in pituitary, ovarian, oviduct, and uterine tissues was significantly lower in STH sheep compared with SNT sheep (P < 0.01). This study revealed that BMPR1B, BMP15, and GDF9 may play important roles in the hypothalamic-pituitary-gonadal axis, especially in the ovary, which may affect sheep prolificacy. BMPR1B and GDF9 expression might increase litter size, whereas BMP15 expression may decrease litter size. These results provide preliminary information regarding molecular regulatory mechanisms underlying sheep prolificacy.

Keywords

• tissue
• candidate gene
• transcription profiling
• qpcr
• prolificacy