The maturation of fish oocytes is a well-characterized system induced by progestins via non-genomic actions. In a previous study, we demonstrated that diethylstilbestrol (DES), a non-steroidal estrogen, induces fish oocyte maturation via the membrane progestin receptor (mPR). Here, we attempted to evaluate the effect of DES as an environmental endocrine disrupting chemical (EDC) upon fish oocyt...

The normal differentiation of follicles from the preantral to the antral stage is regulated by the synthesis and secretion of several important growth factors. Moreover, the proper growth and development of the oocyte and its surrounding somatic granulosa-cumulus cells is accomplished through the activation of paracrine pathways that form a specific cross-talk between the gamete and somatic cel...

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...

Background: Polarized cells are key to the process of differentiation. Xenopus oocyte is a polarized cell that has complete blue-print to differentiate 3 germ layers following fertilization, as key determinant molecules (Proteins and RNAs) are asymmetrically localized. The objective of this work was to localize Na+, K+-ATPase activity along animal-vegetal axis of polarized Xenopus oocyte and fo...

Efforts have intensified to successfully mature and inseminate oocytes in vitro and then culture ensuing embryos to transferable stages from a large number of mammalian species. Success varies, but generally even for the most successful species it is only possible to obtain a maximum of a 40 to 50% development of zygotes to the blastocyst stage. Reduced oocyte developmental competence is sugges...

The causes of embryonic arrest during pre-implantation development are poorly understood. Attempts to correlate patterns of oocyte gene expression with successful embryo development have been hampered by the lack of reliable and nondestructive predictors of viability at such an early stage. Here we report that zygote viscoelastic properties can predict blastocyst formation in humans and mice wi...

Genes involved in the echinoderm block to polyspermy are synthesized primarily in the oocyte. Their expression begins early in oogenesis and continues until germinal vesicle breakdown, when the transcript is rapidly turned over, leaving only traces of the active transcript. These oocyte-specifi c genes encode proteins in the egg extracellular matrix and the cortical granules, secretory vesicles...

Hydrogen sulfide (H2S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H2S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observ...

During mammalian oocyte maturation there are marked changes in the distribution of mitochondria that supply the majority of the cellular ATP. Such redistribution of mitochondria is critical for oocyte quality, as oocytes with a poor developmental potential display aberrant mitochondrial distribution and lower ATP levels. Here we have investigated the dynamics of mitochondrial ATP production thr...