Taxol, a drug which promotes microtubule assembly, was used to assess the microtubule nucleating activity of pericentriolar material (PCM) in mouse oocytes prevented from undergoing germinal vesicle breakdown (GVBD), compared with oocytes allowed to proceed normally through GVBD and also in nucleate and anucleate oocyte fragments. Both immunofluorescence staining and ultrastructural analysis re...

Criollo high Andean cattle are of family economic importance for rural dwellers and contribute to food security. The objective this study was evaluate the quantity, quality, nuclear status ovarian oocytes according body condition cows. Groups cows were formed (1=emaciated, 5=obese): low (≤1.5), moderate (2 2.5) (≥3). Ovaries (n=212) obtained from slaughterhouse. Oocytes recovered by follicular ...

Empty follicle syndrome (EFS) is a condition in which no oocytes are obtained after an apparently successful ovarian stimulation. Genuine EFS (GEFS) is differentiated from false EFS by an optimal level of human chorionic gonadotropin on the day of oocyte retrieval. Some believe that GEFS does not exist and that it is only a reflection of the margin of error attendant upon the procedure of oocyt...

It has been suggested that nucleus replacement (transfer) may be used as an efficient oocyte therapy in order to prevent transmission of mutated mitochondrial DNA from mother to offspring in humans. The essential and not yet answered question is how mitochondria surrounding the karyoplast will be distributed in the newly reconstructed oocytes. In our model experiments, we have evaluated the dis...

in order to determine the most effective hormones on the in vitro oocyte maturation (germinal vesicle breakdown - gvbd) in a hybrid sturgeon bester, ovarian follicles were incubated at the migratory nucleus stage in the presence of several steroids, gonadotropin preparations and forskolin. occurrence of gvbd and 17,20β-dihydroxy-4-pregnen-3 -one (dhp) production were followed during an expe...

Eggs of most animal species are fertilized by a single sperm and fusion of these two cells is essential for the activation of the developmental program of the zygote. Cases in which multiple sperm fertilize an egg, a condition known as polyspermy, the supernumerary paternal centrioles and chromosomes usually create aberrant cell divisions that result in death. Thus, eggs have evolved mechanisms...

The establishment of DNA methylation patterns in oocytes is a highly dynamic process marking gene-regulatory events during fertilization, embryonic development, and adulthood. However, after epigenetic reprogramming in primordial germ cells, how and when DNA methylation is re-established in developing human oocytes remains to be characterized. Here, using single-cell whole-genome bisulfite sequ...

Histological examination of gonadotrophin stimulated Macaca fascicularis ovaries removed at mid-follicular phase showed that germinal vesicles (GV) could exhibit different configurations in follicles greater than 1000 microns in diameter. We describe 3 types of nuclear organization called GV1 (dispersed and filamentous chromatin), GV2 (clumped and filamentous chromatin) and GV3 (perinucleolar c...

In the brachiopod Terebratalia transversa, each ovarian follicle consists of (i) a prophase-arrested oocyte with an enlarged nucleus (= the germinal vesicle, or GV), and (ii) a surrounding sheath of follicle cells that attach to the oocyte by means of junctional complexes. Within about 80 min after removing a follicle from the ovary, the follicular sheath undergoes a microfilament-mediated retr...