ABSTRACT The objective of the present study was to evaluate effect lipopolysaccharide (LPS) administration on activation and apoptosis primordial follicles. There no difference in total number follicles as well different types Furthermore, LPS challenge didn’t modulate expression genes related with ovarian reserve (HAM), oocyte survival (Survivin), rate (Pten, KIT, KITL1, KITL2, AKT1, SIRT1), f...

Background: Chemical activation is the most frequently method for artificial oocyte activation, resultant in high fertilization rates. The aim of this prospective randomized controlled study is evaluating the effect of calcium ionophore on fertilization and pregnancy rate in infertile men suffering from teratoospermia. Materials and Methods: 38 women with teratoospermic partner were divided int...

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...

A transient increase in intracellular Ca(2+) is the universal signal for egg activation at fertilization. Eggs acquire the ability to mount the specialized fertilization-specific Ca(2+) signal during oocyte maturation. The first Ca(2+) transient following sperm entry in vertebrate eggs has a slow rising phase followed by a sustained plateau. The molecular determinants of the sustained plateau a...

We have measured the levels of cyclin mRNAs and polypeptides during oogenesis, progesterone-induced oocyte maturation, and immediately after egg activation in the frog, Xenopus laevis. The mRNA for each cyclin is present at a constant level of approximately 5 x 10(7) molecules per oocyte from the earliest stages of oogenesis until after fertilization. The levels of polypeptides show more comple...

Background: Parthenogenetic activation is a possible way to produce homogeneous embryos with the some ploidy. Probably such embryos could be used in other areas of biotechnology. Calcium signals are known as important regulators of oocyte activation. Extracellular calcium is required for initiation of meiotic resumption and development. Calcium ionophore A23187 is known to elevate intracellular...

Increased glucocorticoid levels, due to medical therapy or stress-related, may affect reproduction via the hypothalamus-pituitary-axis or directly at the oocyte level. We examined the effects of natural (corticosterone) or synthetic (dexamethasone) glucocorticoids on mouse oocyte maturation and underlying changes in extracellular signal-regulated kinase (ERK) phosphorylation patterns. Fertiliza...

Maturation (M-phase) promoting factor (MPF) plays a pivotal role in oocytes during their maturation. This review concentrates on its function at three important time-points. First, its activation during meiotic progression from prophase I arrest at germinal vesicle breakdown. Second, its role during the transition from meiosis I to meiosis II, a defining feature of meiosis involving segregation...

Gene silencing by double-stranded RNA is a widespread phenomenon called RNAi, involving homology-dependent degradation of mRNAs. Here we show that RNAi is established in the Drosophila female germ line. mRNA transcripts are translationally quiescent at the arrested oocyte stage and are insensitive to RNAi. Upon oocyte maturation, transcripts that are translated become sensitive to degradation w...

During the peri-ovulatory period, the gonadotropin LH triggers major changes in both the somatic and germ cell compartments of the ovarian follicle. The oocyte completes the meiotic cell cycle to become a fertilizable egg, and dramatic changes in gene expression and secretion take place in the somatic compartment of the follicle in preparation for follicular rupture and oocyte release. The conc...