In ovarian antral follicles cumulus cells (approximately 1,000/follicle) closely surround the oocyte, and mural granulosa cells (approximately 50,000/follicle) are distributed at the periphery. Previous work (Salustri, A., Yanagishita, M., and Hascall, V. C. (1990) Dev. Biol. 138, 26-32) showed that oocytes produce a factor(s) which stimulates hyaluronic acid (HA) synthesis by cumulus cells dur...

In vivo, resumption of oocyte meiosis occurs in large ovarian follicles after the preovulatory surge of luteinizing hormone (LH). The LH surge leads to the activation of a broad signaling network in mural granulosa cells equipped with LH receptors. The signals generated in the mural granulosa cells are further augmented by locally produced peptides or steroids and transferred to the cumulus cel...

In mammals, gonadotropins stimulate oocyte maturation via the epidermal growth factor (EGF) network, and the protein kinase C (PKC) signaling pathway mediates this process. Tumor necrosis factor-α converting enzyme (TACE) is an important protein responding to PKC activation. However, the detailed signaling cascade between PKC and TACE in follicle-stimulating hormone (FSH)-induced oocyte maturat...

BACKGROUND Successful oocyte in vitro maturation (IVM) would eliminate the need for hormonal stimulation used in assisted reproduction techniques. Unfortunately, oocytes matured in vitro have compromised developmental competence possibly due to disrupted oocyte-cumulus communication resulting from inappropriate levels of oocyte-secreted factors such as growth differentiation factor 9 (GDF9). He...

The two principal functions of ovarian follicles are developmental and endocrine. The cumulus cells surrounding the oocyte are specialized to serve the development of the oocyte and steroidogenesis is a principal role of mural granulosa cells that line the follicle wall. The findings in this report demonstrate that oocytectomy or treatment with an inhibitor of SMAD2/3 activation results in decr...

This study investigated the participation of MAPK in the resumption of meiosis [germinal vesicle breakdown (GVB)] in oocytes and cumulus expansion using oocyte-cumulus cell complexes (OCC) from Mos-null mice (Mos(tm1Ev)/Mos(tm1Ev), hereafter Mos(-/-)). MAPK activity was not detected in Mos(-/-) oocytes whether they matured in vivo or in vitro, with or without gonadotropin stimulation. Therefore...

oocyte maturation and embryo development are controlled by intra-ovarian factors such as steroid hormones. progesterone (p4) exists in the follicular fluid that contributes to normal mammalian ovarian function and has several critical functions during embryo development and implantation, including endometrial receptivity, embryonic survival during gestation and transformation of the endometrial...