Cloning and spatio-temporal expression of bone morphogenetic proteins-2,-4 gene during ovarian development in New Zealand white rabbit

In the transforming growth factor-β(TGF-β) superfamily, bone morphogenetic proteins (BMPs) are one of the largest subfamily, among which BMP-2 and BMP-4 are the most powerful molecules in biological activities. They have been shown to be involved in follicle development of ovary in mammals. However, whether these factors are involved in folliculogenesis in rabbit is still unknown. This study was performed to determine the relationships between ovarian development and the expression of BMP (BMP-2,-4) mRNAs in rabbit. Ovaries were removed from different development stages of rabbits (30-, 60-, 120-, 180-day age and 6-day encyesis), and method of RT-PCR was used for the cloning. The relative transcript levels of BMP-2,-4 genes were measured by real-time quantitative PCR, with GAPDH as an internal control. Known from the results, the BMP-2,-4 genes showed similar but also different expression patterns during ovarian development; they both increased significantly (p < 0.05) in the ovary on 60-day compared with 120-day and 6-day encyesis, and the expression of BMP-2 was always higher than that of BMP-4. The expression law of BMP-2,-4 genes presented in this study may lay the theoretical foundation for the study of BMPs' biological function.