The Mos protein kinase is a key regulator of vertebrate oocyte maturation. Oocyte-specific Mos protein expression is subject to translational control. In the frog Xenopus, the translation of Mos protein requires the progesterone-induced polyadenylation of the maternal Mos mRNA, which is present in the oocyte cytoplasm. Both the Xenopus p42 mitogen-activated protein kinase (MAPK) and maturation-...

LSM family member 14 (LSM14) belongs to the RNA-associated protein (RAP) family that is widely expressed in different species, and whose functions include associating and storing mRNAs. In the present study, we found that LSM14b was essential for oocyte meiotic maturation. Lack of LSM14b caused oocyte meiotic arrest at metaphase, and misalignment of chromosomes, as well as abnormal spindle asse...

With fertilization, the paternal and maternal contributions to the zygote are not equal. The oocyte and spermatozoon are equipped with complementary arsenals of cellular structures and molecules necessary for the creation of a developmentally competent embryo. We show that the nucleolus is exclusively of maternal origin. The maternal nucleolus is not necessary for oocyte maturation; however, it...

The successful outcome of intracytoplasmic sperm injection (ICSI) with round-headed spermatozoa (globozoospermia) and ionomycin assisted activation oocytes is reported. A 30-year-old man with 100% globozoospermia underwent ICSI treatment. Real-time Polymerase Chain Reaction (PCR) detection indicates that the patient was DPY19L2 homozygous deletion. Nine metaphase II oocytes were injected with r...

BACKGROUND Oocyte maturation in fish involves numerous cell signaling cascades that are activated or inhibited during specific stages of oocyte development. The objectives of this study were to characterize molecular pathways and temporal gene expression patterns throughout a complete breeding cycle in wild female largemouth bass to improve understanding of the molecular sequence of events unde...

The HCO(3)(-)/Cl(-) exchanger is quiescent in the unfertilized mouse egg but is highly active in regulating intracellular pH in the early embryo and required for normal development. We show here that the HCO(3)(-)/Cl(-) exchanger is active in first meiotic prophase (GV) oocyte but inactivated during meiotic metaphase before the MI to MII transition. Reactivation does not occur until the activat...

BACKGROUND The LH surge promotes ovulation via activation of multiple signaling networks in the ovarian follicle. Studies in animal models have shown the importance of LH-induced activation of the epidermal growth factor (EGF)signaling network in critical peri-ovulatory events. We investigated the biological significance of regulatory mechanisms mediated by EGF-like growth factors during LH sti...

The aim of the present study was to investigate the effect of follicle stimulating hormone (FSH) on survival, activation and growth of ovine primordial follicles using histological studies. Pieces of ovine ovarian cortex were obtained and cultured for 6 days in Minimum Essential Medium supplemented with or without FSH (50 ng/mL). These fragments were then process to be used for histology compar...

The relationship between onset of the early cytoplasmic stages of oocyte activation (vitelline membrane separation and elevation) and nuclear meiotic maturation was investigated in starfish oocytes after their exposure to divalent ionophore (A-23187) or sperm. Meiotically mature oocytes, isolated in calcium-free seawater, underwent activation in response to sperm or ionophore as previously repo...

The oocyte is a remarkable haploid cell that carries all the information needed to undergo a complex maturation process to become a fertilizable egg and possesses the ability to initiate the early stages of development after fertilization. During the period of oocyte growth, mRNAs are synthesized and stored, and these mRNAs are very stable at this time, with a half-life of approximately 12 days...