Immunohistochemical localization of the bone morphogenetic protein receptors in the porcine ovary

Abstract

The bone morphogenetic protein (BMP) family is emerging as playing a crucial role in regulating normal follicle growth and determining ovulation rate. BMPs exert their effects via BMP receptors (BMPR-IA, -IB and -II). However, there is a paucity of information relating to the expression of the BMPRs within the ovary of large polyovular species such as the pig. Furthermore, there is a lack of information on the expression of BMPRs by fetal ovaries of any species. The purpose of this study was to investigate temporal and spatial expression of the BMPRs in the porcine ovary, at different developmental stages. Immunohistochemistry for BMPR-IA, BMPR-IB and BMPR-II was performed using sections from paraffin wax-embedded ovaries, obtained from fetal (n = 15), prepubertal (n = 3) and cycling postpubertal (n = 4) pigs. Results confirmed the presence of all three receptors in the fetal egg nests and in the granulosa cell layer of follicles ranging from primordial to late antral stages. Immunostaining was also observed in oocytes, theca layer, corpus luteum and ovarian surface epithelium. The expression of BMPRs by fetal ovaries may be related to follicle formation, whereas expression in pre- and post-pubertal animals indicates BMPs are involved in regulating porcine ovarian follicle growth.

Temporal regulation of BMP2, BMP6, BMP15, GDF9, BMPR1A, BMPR1B, BMPR2 and TGFBR1 mRNA expression in the oocyte, granulosa and theca cells of developing preovulatory follicles in the pig

“…Our findings confirmed observations made in the pig, sheep, goat and cow in which BMPR1A, BMPR1B and BMPR2 mRNA and/or protein were expressed in the oocyte and in both GC and TC of antral follicles (Wilson et al 2001, Souza et al 2002, Glister et al 2004, Quinn et al 2004, Fatehi et al 2005, Silva et al 2005, Feary et al 2007). …”

Hormonal regulation of expression of growth differentiation factor-9 receptor type I and II genes in the bovine ovarian follicle

“…Such signaling could well be the result of the action of GDF-9. The expression of ALK-3 and ALK-6 has been reported in rats (Shimasaki et al 1999), pigs (Quinn et al 2004), sheep (Souza et al 2002) and cattle (Glister et al 2004) GCs and TCs. In the early stages of rat follicular development the levels of ALK-3 and ALK-6 mRNA expressions in the GCs increased and abundant expression was maintained in the tertiary and dominant follicular stages (Erickson & Shimasaki 2003).…”

Effect of BMPRIB gene silencing by siRNA on apoptosis and steroidogenesis of porcine granulosa cells

“…The expression of BMPRIB has been reported in GCs of rats (Shimasaki et al, 1999), sheep (Souza et al, 2002), pigs (Quinn et al, 2004), and cattle (Glister et al, 2004). Zou and Niswander (1996) found that in limb mesenchyme expression of dominant negative, BMPRIB results in the increase of apoptosis.…”

“…Plenty of studies have found that the BMPRIB gene plays a crucial role not only in the differentiation and apoptosis of osteoblasts but also in the proliferation and differentiation of granulosa cells, as well as in the development of follicles and in the promotion of ovulation rate. Researches have demonstrated that BMPRIB is present in both granulosa cells and oocytes, respectively, in sheep and pigs (Wilson et al, 2001;Quinn et al, 2004). Souza et al (2001) and Wilson et al (2001) found that partial inactivation of the BMPRIB gene caused by gene mutation leads to an increase of ovulation rate and multiple births.…”