Blastocyst development and birth after in-vitro maturation of human primary oocytes
, intracytoplasmic sperm injection and assisted hatching.
During this phase, follicular diameter increases from 20 to 400 [micro]m due largely to growth of the primary oocyte
growth (size ~ 25-270 [micro]m): The first phase of oocyte growth starts with the arrest of meiosis in diplotene.
At ovulation, usually only 1 primary oocyte
divides to produce a secondary oocyte.
Time-lapse cinematography study of the germinal vesicle behaviour in mouse primary oocytes
treated with activators of protein kinases A and C.
in the control group were oval-shaped cells with oval nucleus and large nucleolus.
An intermediate cell type in oogenesis arising from an oogonium and remaining in the first meiotic prophase until ovulation.
1-2, 3a-g; 11a), the ovarian germinal epithelium consists of somatic NPs and germ cells, including amitotic oogonia (AOs); irregularly or conically shaped residual vitellogenic primary oocytes
(RVPOs); and a few large residual ova (Os) (Fig.
Large numbers of primary oocytes
were presented in immature and inactive states of ovaries which showed no evidence of development towards the next stage.
From live selected animals, repeated recovery of primary oocytes
using ovum pick up procedures (OPU) is possible [7, 8].
The in vitro embryo production (IVEP) system includes three major steps, namely in vitro maturation (IVM) of the primary oocytes
, in vitro fertilization (IVF) of the matured oocytes and in vitro culture (IVC) of presumptive embryos, until transferred or cryopreserved for future use (Gandolfi et al.
2003), all oocytes that will be spawned during the upcoming season develop during these 2 stages, leaving a group of primary oocytes
as a reserve for the successive spawning season.
We recorded the reproductive state of adult females as follows: premature females (primary oocytes
small and not yet developed, white or translucent, with no yellow yolk), mature females before first laying (yellow yolk deposit in primary oocytes
; four classes according to the length of the primary oocytes
(= the first row of oocytes): <1/4, 1/4-1/2, 1/23/4, >3/4 of the maximal 6-mm length), postoviposition females (1st, 2nd or 3rd egg pod already laid, based on the number of white follicle resorption bodies at the base of each ovariole--Albrecht 1956, Launois-Luong 1978, Sundberg et al.
In vitro maturation of bovine cumulus enclosed primary oocytes
and their subsequent in vitro fertilization and cleavage.
Stage 1 (regressed or regressing) was the nonspawning condition consisting mainly of primary oocytes