Ramirez George, Palomino Jaime, Aspee Karla, De Los Reyes Monica
Laboratory of Animal Reproduction, Department of Animal Production, Faculty of Veterinary Sciences, University of Chile, Santiago 8320000, Chile.
Animals (Basel). 2020 Mar 10;10(3):462. doi: 10.3390/ani10030462.
The competence to undergo expansion is a characteristic of cumulus cells (CCs). The aim was to investigate the expression of and mRNA in canine cumulus cells in relation to cumulus expansion and meiotic development over the estrous cycle. CCs were recovered from nonmatured and in vitro-matured (IVM) dog cumulus oocyte complexes (COCs), which were obtained from antral follicles at different phases of the estrous cycle. Quantitative real-time polymerase chain reaction (q-PCR) was used to evaluate the relative abundance of and transcripts from the CCs with or without signs of expansion. The results were evaluated by ANOVA and logistic regression. The maturity of the oocyte and the expansion process affected the mRNA levels in CCs. There were differences ( < 0.05) in and gene expression in CCs isolated from nonmatured COCs when comparing the reproductive phases. Lower mRNA levels ( < 0.05) were observed in anestrus and proestrus in comparison to those in estrus and diestrus. In contrast, when comparing mRNA levels in IVM COCs, no differences were found among the phases of the estrous cycle in expanded and nonexpanded CCs ( < 0.05). However, the highest ( < 0.05) gene expression in CCs that did not undergo expansion was exhibited in anestrus and the lowest ( < 0.05) expression was observed in estrus in expanded CCs. Although the stage of the estrous cycle did not affect the second metaphase (MII )rates, the expanded CCs obtained at estrus coexisted with higher percentages of MII ( < 0.05). In conclusion, the differential expression patterns of and mRNA transcripts might be related to cumulus expansion and maturation processes, suggesting specific regulation and temporal changes in their expression.
具备增殖能力是卵丘细胞（CCs）的一个特征。本研究旨在探讨犬卵丘细胞中与发情周期中卵丘扩展和减数分裂发育相关的 和 信使核糖核酸（mRNA）的表达情况。从发情周期不同阶段的有腔卵泡中获取未成熟和体外成熟（IVM）的犬卵丘卵母细胞复合体（COCs），并从中回收CCs。采用定量实时聚合酶链反应（q-PCR）评估有或无扩展迹象的CCs中 和 转录本的相对丰度。结果通过方差分析和逻辑回归进行评估。卵母细胞的成熟度和扩展过程会影响CCs中的mRNA水平。比较生殖阶段时，从未成熟COCs中分离出的CCs中 和 基因表达存在差异（P<0.05）。与发情期和间情期相比，在乏情期和发情前期观察到较低的mRNA水平（P<0.05）。相比之下，比较IVM COCs中的 mRNA水平时，在扩展和未扩展的CCs中，发情周期各阶段之间未发现差异（P<0.05）。然而，未发生扩展的CCs中 基因表达在乏情期最高（P<0.05），在扩展的CCs中发情期观察到最低表达（P<0.05）。尽管发情周期阶段不影响第二中期（MII）比率，但在发情期获得的扩展CCs与较高比例的MII共存（P<0.05）。总之， 和 mRNA转录本的差异表达模式可能与卵丘扩展和成熟过程有关，表明其表达存在特定调控和时间变化。
