The germinal vesicle of the mature Chaetopterus egg is invested by an envelope which can be seen in electron micrographs to contain "pores" in its bilaminar structure. While under continuous microscopic observation, individual germinal vesicles were isolated in various test solutions by an extremely gentle method. Repeated measurements of nuclear diameter and of optical path differences with an...

Mitochondria are responsible for the production of ATP, which drives cellular metabolic and biosynthetic processes. This is the first study to quantify the mtDNA copy number across all stages of oogenesis in a large monovulatory species, it includes assessment of the activity of mitochondria in germinal vesicle (GV) and metaphase II (MII) oocytes through JC1 staining. Primordial to early antral...

In the present study, the response of Nili Ravi buffalo oocytes to recombinant human follicle stimulating hormone (rhFSH) (Organon) on meiotic maturation in vitro was examined. Oocytes were matured in vitro in medium containing either 0 or 0.05 IU/ ml rhFSH and the stage of nuclear maturation recorded after 24 hours. The percentage of oocytes in the control group undergoing germinal vesicle bre...

Tosti, Elisabetta, Raffaele Boni, and Annunziata Cuomo. Ca current activity decreases during meiotic progression in bovine oocytes. Am J Physiol Cell Physiol 279: C1795–C1800, 2000.—By using the whole cell voltage-clamp technique, we studied changes in plasma membrane permeability at different meiotic stages of bovine oocytes. Follicular oocytes were matured in vitro and activated by Ca ionopho...

The amorphous nucleoplasm of the germinal vesicle nucleus of Xenopus laevis oocytes has been selectively extracted under conditions which leave the nuclear formed elements morphologically intact. The nucleoplasm contains about 97% of the total nuclear proteins and on SDS-polyacrylamide gels some 68 polypeptides can be distinguished. On the basis of solubility differences, the nucleoplasmic prot...

Cyclin J is a cyclin family member that appears to have evolved before the metazoan radiation. Its evolutionary conservation argues for an important role but functional characterizations of Cyclin J have remained very limited. In Drosophila, Cyclin J is expressed only in females. Using transgenic Drosophila lines expressing Cyclin J versions with N- or C-terminal GFP extensions, we demonstrate ...

The SUN (Sad-1/UNC-84) and KASH (Klarsicht/ANC-1/Syne/homology) proteins constitute the linker of nucleoskeleton and cytoskeleton (LINC) complex on the nuclear envelope. To date, the SUN1/KASH5 complex is known to function as meiotic-specific factors. In this study, gene-silencing methods were used to explore the roles of SUN1 and KASH5 in mouse oocytes after prophase. SUN1 was detected through...

OBJECTIVE Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). METHODS We evaluated the loss-of-function of ...

In many eukaryotes, condensins I and II associate with chromosomes in an ordered fashion during mitosis and play nonoverlapping functions in their assembly and segregation. Here we report for the first time the spatiotemporal dynamics and functions of the two condensin complexes during meiotic divisions in mouse oocytes. At the germinal vesicle stage (prophase I), condensin I is present in the ...

Background Salvia officinalisL. has been used since ancient times but there are little data about effects of this herb on normal reproductive cells. Objective To investigate the toxicity effects of Salvia officinalis L. on granulosa cells (GCs) and maturation of oocytes. Materials and Methods GCs and oocytes were extracted from superovulated ovaries of immature mice. The cells were treated ...