When meiosis is restored in early stages, the oocytes possess the visible nuclei, called germinal vesicles (GV) and this GV undergoes a germinal vesicles breakdown (GVBD
) (i.e., termination of the nuclear membrane) (Grondahl, 2008).
Induction of germinal vesicle break down (GVBD
) in vitro by metabolic hormones in frog (Euphlyctis cyanophlyctis) oocytes.
, microvilli surrounding MI oocytes are common and large in size.
Trypan blue (TB) staining, GVBD
, fertilization and hatching rates were submitted to a one-factor analysis of variance (one-way ANOVA) at 5% significance level.
GSI 31-45% Actively PG, GVM, GVBD
, Ovaries occupy all the volume of the spawning hydration, body cavity, opaque, gray, or pink.
This redistribution of mitochondria results in a burst of ATP production during oocyte maturation , the importance of which is highlighted by the fact that mitochondrial damage potently comprises GVBD
, formation of the meiotic spindles, chromosome segregation, and polar body extrusion .
Germinal vesicle (GV), germinal vesicle breakdown (GVBD
), Metaphase I (MI), Anaphase/Telophase I (ATI), and Metaphase II (MII) stages mouse oocytes were collected after being cultured in M16 medium for 0, 4, 8, 9.5, or 14 h, respectively.
The oocyte maturation begins with germinal vesicle migration (GVM, early hydration), going to germinal vesicle breakdown (GVBD
, middle hydration) and hydrated oocyte stage (HO, final hydration) when it is previous to spawning (Figure 2e-f).
in seawater, the egg envelope lifts slightly off the oocyte surface and becomes even more conspicuous following fertilization (Fig.
Related to the function of MAF, we have identified that, in culture, adrenomedullin (ADM), a multifunctional hormone that regulates cell growth, potently suppresses germinal vesicle breakdown (GVBD
), the initial morphologic change in the induction of oocytes.
On the other hand cryopreservation of an intermediate stage oocyte such as GVBD
has been thought to avoid some of the cryoinjuries associated with cryopreservation of GV or MII oocytes (Fuku et al.