The effects of different types of media on in vitro maturation outcomes of human germinal vesicle oocytes retrieved in intracytoplasmic sperm injection cycles / 대한생식의학회지

OBJECTIVE: Optimizing in vitro maturation (IVM) media to achieve better outcomes has been a matter of interest in recent years. The aim of this prospective clinical trial was to investigate the effects of different media on the IVM outcomes of immature oocytes at the germinal vesicle (GV) stage. METHODS: A total of 400 immature oocytes at the GV stage with normal morphology were retrieved from 320 infertile women aged 31±4.63 years during stimulated intracytoplasmic sperm injection (ICSI) cycles. They were divided into groups of homemade IVM medium (I, n=100), cleavage medium (II, n=100), blastocyst medium (III, n=100), and Sage IVM medium (IV, n=100) and cultured for 24 to 48 hours at 37℃. ICSI was performed, and the rates of fertilization and embryo formation were compared across the four groups. RESULTS: In the 400 retrieved GV oocytes, the total maturation rates showed significant differences in groups I to IV (55%, 53%, 78%, and 68%, respectively, p<0.001). However, there were no significant differences in the fertilization, embryo formation, or arrest rates of metaphase II oocytes across these groups. In all groups, GV maturation was mostly completed after 24 hours, with fewer oocytes requiring 48 hours to mature (p<0.01). Moreover, the rate of high-quality embryos was higher in group IV than in the other groups (p=0.01). CONCLUSION: The quality of the IVM medium was found to affect clinical IVM outcomes. Additionally, blastocyst medium may be a good choice in IVM/ICSI cycles as an alternative IVM medium.

Role of 1 4-3-3εand Cdc25B in GV-stage arrest of mouse oocytes / 吉林大学学报(医学版)

Objective:To study the role of 14-3-3εand Cdc25B in germinal vesicle (GV)-stage arrest of mouse oocytes,and to pay foundation for further study on the molecular mechanism of PKA/Cdc25B/14-3-3εpathway in GV-stage arrest of mouse oocytes.Methods:The eukaryotic expression vectors of pcDNA3.1-ZEO-HA-14-3-3ε, pcDNA3.1-MYC-Cdc25B-WT, pcDNA3.1-MYC-Cdc25B-S321A, and pcDNA3.1-MYC-Cdc25B-S321D were transcribed into mRNA invitro.The mouse GV-stage oocytes were collected after superovulation and divided into no injection group,TE buffer microinjection group,14-3-3εmRNA injection group,14-3-3εmRNAs + Cdc25B-WT mRNA injection group,and 14-3-3εmRNA + Cdc25B-S321A mRNA injection group,14-3-3εmRNA+Cdc25B-S321D mRNA injection group.The protein expression levels of HA-14-3-3εand MYC-Cdc25B and the phosphorylation status of Cdc2-pTyr15 were observed by Western blotting method.The morphological changes and germinal vesicle breakdown (GVDB)rates of mouse oocytes were observed under phase-contrast microscope. Results:None of the oocytes in no injection group, TE buffer microinjection group, 14-3-3εmRNA injection group,14-3-3εmRNA + Cdc25B-WT mRNAs injection group and 14-3-3εmRNA + Cdc25B-S321D mRNA were able to undergo GVBD until at least 20 h after injection (P>0.05 );the GVBD rates of oocytes in 14-3-3εmRNA+Cdc25B-S321A mRNA group at 1 h (5.00%±0.68%),2 h (62.00%±3.56%)and 3 h (100.00%± 0.00%)after injection were significantly higher than those in no injection group and TE buffer injection group (P<0.01);the oocytes in 14-3-3εmRNA+ Cdc25B-Ser321A mRNA group at 20 h (79.00%±2.80%)after injection progressed to MII (P<0.01).Conclusion:14-3-3εcan regulate the transition from GV to GVBD of mouse oocytes by means of phosphorylation and dephosphorylation of S321-Cdc25B.

Influence of stages anestrous and diestrus in chromatin configuration in germinal vesicle of canine oocytes / Influência das fases de anestro e diestro sobre a configuração da cromatina em vesícula germinativa de oócitos caninos

In canine specie, oocyte maturation rates are low and the percentage of oocytes that remain in the stage of germinal vesicle (GV) regardless of culture conditions is high. During maturation oocyte undergoes modification and the GV chromatin remodeling manifested by changes in the configuration and positioning. The objective of this work is to evaluate the configuration and positioning of chromatin of oocytes in GV stage during anestrus and diestrus bitches. The ovaries of 33 females (20 bitches in anestrous and 13 in diestrus) were isolated, sliced and only cumulus-oocyte complexes (COCs) grade 1 were subjected to solution of 0.2% hyaluronidase for release in cumulus cells. After this process, the selected oocytes were stained and evaluated. From a total of 920 oocytes, 566 were classified as grade 1 and the stages of chromatin configuration identified as GV-1, GV-2, GV-3 and GV-4. The observed changes in chromatin configuration been characterized as a transition dispersed chromatin (GV-1, GV-2) for partially condensed (GV-3) until it reaches a fully condensed stage (GV-4). The data analyzed from the chromatin configuration showed a significant difference between the stages with a higher proportion of GV-1 and GV-2 for the anoestrus and GV-3 and GV-4 during diestrus. There is need for further studies to be able to have a proper understanding of the influence of chromatin configuration of oocytes in GV stage in resumption of meiosis and consequently in oocyte meiotic competence...

Na espécie canina as taxas de maturação oocitária são baixas e a porcentagem de oócitos que permanecem em estagio de vesícula germinativa (VG), independente das condições de cultivo, e alta. Durante a maturação oocitária, a VG sofre modificação e remodelamento da cromatina, que se manifesta por alterações na sua configuração e posicionamento. Assim, o objetivo deste trabalho e avaliar a configuração e o posicionamento da cromatina de oócitos em estagio de VG durante o anestro e diestro de cadelas. Os ovários de 33 fêmeas (20 cadelas em anestro e 13 em diestro) foram isolados, fatiados e os complexos cumulus-oócitos (COCs) foram submetidos à solução de hialuronidase 0,2% para a liberação das células do cumulus. Apos esse processo, os oócitos selecionados foram corados, avaliados e apenas COCs grau 1 foram utilizados. De um total de 920 oócitos, 566 foram classificados como grau 1 e os estágios de configuração da cromatina identificados como VG-1, VG-2, VG-3 e VG-4. As alterações observadas na configuração da cromatina foram caracterizadas como transição de uma cromatina dispersa (VG-1, VG-2) para parcialmente condensada (VG-3) ate atingir um estagio totalmente condensado (VG-4). Os dados analisados da configuração da cromatina mostraram uma diferença significativa entre as fases de anestro e diestro, com maior proporção de VG-1 e VG-2 durante o anestro e de VG-3 e VG-4 durante o diestro. Ha necessidade de novos estudos para uma compreensão adequada da influencia da configuração da cromatina de oócitos no estagio de VG na retomada da meiose e na competência meiótica do oócito...

Comparing Results with Immature Germinal Vesicle Oocytes From Different In-vitro Fertilization Cycles / 中山大学学报(医学科学版)

[Objective] This study compared outcomes of in vitro maturation (IVM) and in vitro fertilization (IVF) intracytoplasmic sperm injection (ICSI) cycles after IVM of immature germinal vesicle (GV) oocytes.[Methods] ICSI was performed on metaphase II (MII) oocytes retrieved in 163 IVF-ICSI cycles (group I;n ＝ 987) or matured from GV stage oocytes in IVF-ICSI ( group II;n ＝ 132) and 37 IVM cycles ( group III;n ＝ 235).Fertilization and cleavage rates and embryo quality were compared among the three groups.[Results] The fertilization rate,cleavage rate and top quality embryos rate were higher in group I than group II and group III (84.9%,98.1%,and 61.6%;72.0%,90.5% and 22.1%l;75.3%,94.4%,and 25.1%,respectively).Blastomere numbers and morphology scores were highest in group I (P ＜ 0.05),but no significant differences existed between group II and group III.[Conclusion] The morphology of embryos developed from in vivo MII oocytes was superior to those from in vitro matured MII oocytes.No significant difference was observed in embryo morphology from immature GV oocytes in IVF and IVM cycles.