Booroola BMPR1B mutation alters early follicular development and oocyte ultrastructure in sheep.

Booroola ewes homozygous (BB) for a mutation in the bone morphogenetic protein receptor-1b (BMPR1B) gene exhibit higher ovulation rates, have larger diameter oocytes at earlier stages of follicular development (i.e. Type 3) and smaller diameter follicles at ovulation than wild-type (++) sheep.

The role of IGFs in the regulation of ovarian follicular growth in the brushtail possum (Trichosurus vulpecula).

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro.

Expression of mRNAs encoding oestrogen receptor (ER) alpha and ERbeta, androgen receptor and progesterone receptor during gonadal and follicular development in the marsupial brushtail possum (Trichosurus vulpecula).

The objective of the present study was to determine which ovarian cells express mRNAs for oestrogen (ERalpha and ERbeta), androgen (AR) and progesterone (PR) receptors during ovarian and follicular development in the brushtail possum. Expression of ERalpha and/or ERbeta mRNA was observed from birth, initially in cells of the blastema, then in the medullary cords from Day 20. ERalpha was expressed in the oocytes and granulosa cells of secondary and antral follicles.

The role of bone morphogenetic proteins 2, 4, 6 and 7 during ovarian follicular development in sheep: contrast to rat.

The intraovarian roles of BMP family members such as BMP2, 4, 6 and 7 are not well understood, particularly in species with low ovulation rates such as sheep. Therefore, the objectives of these experiments were to determine the expression patterns of mRNAs encoding BMP2, 4, 6 and 7 during ovarian follicular development in sheep, and to determine the effects of these growth factors on ovine granulosa cell functions in vitro. For comparative purposes, the effects of these BMPs were also determined in rat granulosa cells since these factors have been most widely studied in this poly-ovulatory species.

The role of transforming growth factor-beta (TGF-beta) during ovarian follicular development in sheep.

Background: Recently, several members of the transforming growth factor-beta (TGF-beta) superfamily have been shown to be essential for regulating the growth and differentiation of ovarian follicles and thus fertility.

Methods: Ovaries of neonatal and adult sheep were examined for expression of the TGF-betas 1-3 and their receptors (RI and RII) by in situ hybridization using ovine cDNAs. The effects of TGF-beta 1 and 2 on proliferation and differentiation of ovine granulosa cells in vitro were also studied.