Relative in vitro effectiveness of 17α,20β-dihydroxy-4-pregnen-3-one and other pregnene derivatives on germinal vesicle breakdown in oocytes of ayu (Plecoglossus altivelis), amago salmon (Oncorhynchus rhodurus), rainbow trout (Salmo gairdneri), and goldfish (Carassius autatus)

1983 ◽  
Vol 51 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Yoshitaka Nagahama ◽  
Keiji Hirose ◽  
Graham Young ◽  
Shinji Adachi ◽  
Keiko Suzuki ◽  
...  
1992 ◽  
Vol 12 (7) ◽  
pp. 3192-3203 ◽  
Author(s):  
K M Pickham ◽  
A N Meyer ◽  
J Li ◽  
D J Donoghue

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.


Zygote ◽  
2005 ◽  
Vol 13 (4) ◽  
pp. 303-308 ◽  
Author(s):  
H. Iwata ◽  
T. Hayashi ◽  
H. Sato ◽  
K. Kimura ◽  
T. Kuwayama ◽  
...  

During ovary storage oocytes lose some of their developmental competence. In the present study, we maintained storage solutions of phosphate-buffered saline (PBS) at various temperatures (20 or 35 °C) or supplemented them with magnesium (Mg), raffinose and sucrose. Subsequently, we examined the kinetics of electrolytes in the follicular fluid (FF) during the ovary storage period (9h), the survival rate of granulosa cells in the follicles, and the developmental competence of oocytes after the storage. Lowering the temperature from 35 to 20 °C increased the total cell number of blastocysts that developed at 7 days after in vitro maturation and in vitro fertilization of oocytes. In stock solution with supplements of 15 mM Mg or a combination of 5 mM Mg and 10 mM raffinose or sucrose, a significantly higher number of oocytes developed into blastocysts with a large number of cells in each blastocyst, and a significantly higher number of living granulosa cells were obtained as compared with stock solutions without any supplements. During ovary storage, the concentrations of potassium and chloride in the FF were increased, and the addition of Mg to the stock solution increased the concentration of Mg in the FF. Germinal vesicle breakdown in oocytes that were collected from ovaries stored in the solution supplemented with 15 mM Mg or a combination of 5 mM Mg and 10 mM of raffinose occurred at a slower rate than that in oocytes collected from ovaries stored in PBS alone. On the other hand, the oocytes collected from ovaries stored in the solution supplemented with 15 mM Mg or a combination of 5 mM Mg and 10 mM raffinose reached the metaphase II (MII) stage more rapidly than the oocytes collected from ovaries stored in the PBS alone. In conclusion, the modification of stock solution by the addition of Mg and raffinose improved the developmental competence of oocytes obtained from ovaries preserved for a long period.


Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 223-231 ◽  
Author(s):  
Wei Shen ◽  
Lan Li ◽  
Zhaodai Bai ◽  
Qingjie Pan ◽  
Mingxiao Ding ◽  
...  

Little is known about the mechanisms underlying primordial follicular formation and the acquisition of competence to resume meiosis by growing oocytes. It is therefore important to establish anin vitroexperimental model that allows one to study such mechanisms. Mouse follicular development has been studiedin vitroover the past several years; however, no evidence has been presented showing that mature oocytes can be obtained from mouse fetal germ cells prior to the formation of primordial follicles. In this study, a method has been established to obtain mature oocytes from the mouse fetal germ cells at 16.5 days postcoitum (dpc). From the initiation of primordial follicular formation to the growth of early secondary follicles, ovarian tissues from 16.5 dpc fetal mice were culturedin vitrofor 14 days. Subsequently, 678 intact secondary follicles were isolated from 182 mouse fetal ovaries and cultured for 12 days. A total of 141 oocytes inside antral follicles were maturedin vitro, and 102 oocytes underwent germinal vesicle breakdown. We found that 97 oocytes were fertilized and 15 embryos were able to form morula–blastocysts. We also analyzed various genomic imprinting markers and showed that the erasure of genomic imprinting markers in the parental generation was also imposed on the oocytes that developed from fetal germ cells. Our results demonstrate that mouse fetal germ cells are able to form primordial follicles with ovarian cells, and that oocytes within the growing follicles are able to mature normallyin vitro.


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