Light induced injury in mouse embryos revealed by single-cell RNA sequencing

We adopt mouse pre-implantation embryos to evaluate the effects of different exposure time and illumination intensity. The damage-causing time and intensity is chosen to treat embryos at 2-cell stage. Single-cell transcriptomes from 2-cell to blastocyst stage are analyzed under both control and high-intensity light conditions. These data show that embryo cells at each embryonic stage can be categorized into different light conditions. Further analyses of differentially expressed genes and relative GO terms reveal the light-induced injury as well as the potential repair response after high-intensity illumination treatment. Maternal-to-zygote transition is also affected through the failure of removing maternal RNAs and deactivating zygotic genomes. In conclusion, our work revealed integrated response of high-intensity light, involving the long-lasting injury effects, damage repair mechanism and blastocyst morphology changes.

本研究以小鼠植入前胚胎为实验材料，评估不同暴露时长与光照强度对胚胎的影响。本研究选取可造成损伤的光照时长与强度，对2细胞期胚胎进行处理。分别在对照组与高强度光照条件下，分析2细胞期至囊胚期的单细胞转录组数据。结果显示，各胚胎发育阶段的细胞可依据光照条件进行聚类区分。进一步对差异表达基因及相关基因本体（Gene Ontology, GO）条目进行分析，揭示了高强度光照诱导的细胞损伤，以及光照处理后潜在的修复应答机制。母源-合子转换过程亦受影响，具体表现为母源RNA清除失败与合子基因组激活受阻。综上，本研究揭示了高强度光照引发的整体性应答反应，涵盖持续存在的损伤效应、损伤修复机制以及囊胚形态学变化。