School of Life Sciences and Biotechnology & Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
Department of Histo-Embryology, Genetics and Developmental Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Cell Prolif. 2022 Jun;55(6):e13231. doi: 10.1111/cpr.13231. Epub 2022 May 18.
Early embryo development is dependent on the regulation of maternal messages stored in the oocytes during the maternal-to-zygote transition. Previous studies reported variability of oocyte competence among different inbred mouse strains. The present study aimed to identify the maternal transcripts responsible for early embryonic development by comparing transcriptomes from oocytes of high- or low- competence mouse strains.
In vitro fertilization embryos from oocytes of different mouse strains were subject to analysis using microarrays, RNA sequencing, real-time quantitative PCR (RT-qPCR) analysis, Western blotting, and immunofluorescence. One candidate gene, Prkce, was analysed using Prkce knockout mice, followed by a cRNA rescue experiment.
The fertilization and 2-cell rate were significantly higher for FVB/NJ (85.1% and 82.0%) and DBA/2J (79.6% and 76.7%) inbred mouse strains than those for the MRL/lpr (39.9% and 35.8%) and 129S3 (35.9% and 36.6%) strains. Thirty-nine differentially expressed genes (DEGs) were noted, of which nine were further verified by RT-qPCR. Prkce knockout mice showed a reduced 2-cell rate (Prkce 80.1% vs. Prkce 32.4%) that could be rescued by Prkce cRNA injection (2-cell rate reached 76.7%). Global transcriptional analysis revealed 143 DEGs in the knockout mice, which were largely composed of genes functioning in cell cycle regulation.
The transcription level of maternal messages such as Prkce in mature oocytes is associated with different 2-cell rates in select inbred mouse strains. Prkce transcript levels could serve as a potential biomarker to characterize high-quality mature oocytes.
早期胚胎发育依赖于母源信息在母-合子过渡期间储存于卵子中的调控。先前的研究报道了不同近交系小鼠品系的卵母细胞能力存在变异性。本研究旨在通过比较高或低能力的小鼠品系的卵母细胞转录组，来鉴定负责早期胚胎发育的母源转录本。
使用微阵列、RNA 测序、实时定量 PCR（RT-qPCR）分析、Western 印迹和免疫荧光对来自不同小鼠品系卵母细胞的体外受精胚胎进行分析。对一个候选基因 Prkce 进行分析，使用 Prkce 敲除小鼠进行分析，然后进行 cRNA 拯救实验。
FVB/NJ（85.1%和 82.0%）和 DBA/2J（79.6%和 76.7%）近交系小鼠的受精率和 2 细胞率显著高于 MRL/lpr（39.9%和 35.8%）和 129S3（35.9%和 36.6%）品系。注意到 39 个差异表达基因（DEGs），其中 9 个通过 RT-qPCR 进一步验证。Prkce 敲除小鼠的 2 细胞率降低（Prkce 80.1% vs. Prkce 32.4%），可通过 Prkce cRNA 注射挽救（2 细胞率达到 76.7%）。全转录组分析显示，敲除小鼠中有 143 个 DEGs，这些基因主要参与细胞周期调控。
成熟卵母细胞中母源信息如 Prkce 的转录水平与某些近交系小鼠品系的不同 2 细胞率有关。Prkce 转录本水平可作为鉴定高质量成熟卵母细胞的潜在生物标志物。
