The specification of cell fates along the dorsoventral axis of the Drosophila embryo is dependent on the asymmetric distribution of proteins within the egg and within the egg's outer membranes. Such asymmetries arise during oogenesis and are dependent on multiple cell-cell interactions between the developing oocyte and its neighboring somatic follicle cells. The earliest known such interaction ...

Background: The biochemical characteristics of the follicular fluid (FF) play essential role in oocyte quality, the subsequent fertilization potential and embryo development. The oocyte quality and metabolism largely depends on follicular microenvironment. Present study aimed to investigate the relationship between oocyte quality and FF homocysteine (Hcy) level in women undergoing to IVF treatm...

The mammalian oocyte undertakes a highly complex journey to maturity during which it successively acquires a series of characteristics necessary for fertilization and the development of a healthy embryo. While the contribution of granulosa cells to oocyte development has been studied for many years, it has recently become apparent that the oocyte itself plays a key role in directing its own fat...

The epigenetic factors causing competence differences between SN (surrounded nucleolus) and NSN (non-surrounded nucleolus) oocytes, the significance for the increased histone acetylation and methylation in SN oocytes, and whether chromatin configuration or histone modification determines oocyte competence, are unclear. This study has addressed these issues by using the ovary-holding (OH) stress...

The inhibitor CEP-33779 is a specific selective inhibitor of JAK2. In most somatic cells, JAK2 plays essential roles in cellular signal transduction and in the regulation of cell cycle. Little is known regarding the effects of JAK2 on mammalian oocyte maturation. In the present study, we investigated the effects of CEP-33779 on mouse oocytes meiosis and possible mechanisms of JAK2 during mouse ...

We describe a cell-free extract derived from the oocytes of Xenopus laevis. The oocyte extract is capable of decondensing sperm chromatin and of replicating single-stranded DNA in a semiconservative, aphidicolin-sensitive manner. In addition, oocyte extract supports the elongation phase of DNA synthesis in nuclei that have been preinitiated for replication. All of these properties are shared by...

I N the adult hen each oocyte is surrounded by a capsule of follicle cells and all the raw materials that enter the oocyte must pass through this capsule. It is not surprising, therefore, that the morphological relationships between the follicle and the oocyte are of a highly specialized nature. Several workers have studied them, mainly by light microscopy, but their findings have not been unan...

Oocyte quality is the resultant of multifactor interactions that should be carefully taken into account either for in vitro embryo production technologies or for studying follicle dynamics. Different approaches may be used to perform an analysis of variables related to oocyte quality which may focus on the ovary, the follicle, the cumulus-oocyte complex and, finally, the oocyte. The information...

Wen-Shiun Yueh and Ching-Fong Chang (2000) Morphological changes and competence of maturing oocytes in the protandrous black porgy, Acanthopagrus schlegeli. Zoological Studies 39(2): 114-122. The study objectives aimed to investigate the morphological changes of oocytes during final oocyte maturation and ovulation, and the maturational competence of oocytes to respond to maturation-inducing ste...

Ovarian folliculogenesis is regulated by both endocrine and intraovarian mechanisms that coordinate the processes of oocyte growth and somatic cell proliferation and differentiation. Within the follicle, paracrine interactions between the oocyte and surrounding granulosa cells are critical for normal cell development and function. This review focuses on the role of paracrine interactions during...