Laboratory of Mammalian Molecular Embryology, College of Animal Sciences, Zhejiang University, Hangzhou, China.
Reproduction. 2023 Feb 8;165(3):325-333. doi: 10.1530/REP-22-0269. Print 2023 Mar 1.
The lineage specification during early embryonic development in cattle remains largely elusive. The present study determines the effects of trophectoderm-associated factors GATA3 and CDX2 on lineage specification during bovine early embryonic development.
Current understandings of the initiation of the trophectoderm (TE) program during mammalian embryonic development lack evidence of how TE-associated factors such as GATA3 and CDX2 participate in bovine lineage specification. In this study, we describe the effects of TE-associated factors on the expression of lineage specification marker genes such as SOX2, OCT4, NANOG, GATA6, and SOX17, by using cytosine base editor system. We successfully knockout GATA3 or CDX2 in bovine embryos with a robust efficiency. However, GATA3 or CDX2 deletion does not affect the developmental potential of embryos to reach the blastocyst stage. Interestingly, GATA3 deletion downregulates the NANOG expression in bovine blastocysts. Further analysis of the mosaic embryos shows that GATA3 is required for NANOG in the TE of bovine blastocysts. Single blastocyst RNA-seq analysis reveals that GATA3 deletion disrupts the transcriptome in bovine blastocysts. Altogether, we propose that GATA3 plays an important role in maintaining TE lineage program in bovine embryos and the functional role of GATA3 is species-specific.
牛早期胚胎发育过程中的谱系特化在很大程度上仍难以捉摸。本研究旨在确定滋养外胚层相关因子 GATA3 和 CDX2 对牛早期胚胎发育过程中谱系特化的影响。
目前对于哺乳动物胚胎发育中滋养外胚层（TE）程序启动的理解缺乏证据表明，像 GATA3 和 CDX2 这样的 TE 相关因子如何参与牛谱系特化。在这项研究中，我们使用胞嘧啶碱基编辑器系统描述了 TE 相关因子对谱系特化标记基因（如 SOX2、OCT4、NANOG、GATA6 和 SOX17）表达的影响。我们成功地以较高的效率敲除了牛胚胎中的 GATA3 或 CDX2。然而，GATA3 或 CDX2 的缺失并不影响胚胎达到囊胚阶段的发育潜力。有趣的是，GATA3 的缺失下调了牛囊胚中的 NANOG 表达。对嵌合体胚胎的进一步分析表明，GATA3 对于牛囊胚中滋养外胚层的 NANOG 是必需的。单个囊胚 RNA-seq 分析显示，GATA3 的缺失破坏了牛囊胚中的转录组。总的来说，我们提出 GATA3 在维持牛胚胎中滋养外胚层谱系程序中发挥重要作用，并且 GATA3 的功能作用具有物种特异性。
