Department of Animal Sciences, Genetics Institute, University of Florida, Gainesville, FL, USA.
Colorado Center for Reproductive Medicine, Lone Tree, CO, USA.
Biol Reprod. 2024 Jul 12;111(1):11-27. doi: 10.1093/biolre/ioae031.
Profiling bovine blastocyst transcriptome at the single-cell level has enabled us to reveal the first cell lineage segregation, during which the inner cell mass (ICM), trophectoderm (TE), and an undefined population of transitional cells were identified. By comparing the transcriptome of blastocysts derived in vivo (IVV), in vitro from a conventional culture medium (IVC), and in vitro from an optimized reduced nutrient culture medium (IVR), we found a delay of the cell fate commitment to ICM in the IVC and IVR embryos. Developmental potential differences between IVV, IVC, and IVR embryos were mainly contributed by ICM and transitional cells. Pathway analysis of these non-TE cells between groups revealed highly active metabolic and biosynthetic processes, reduced cellular signaling, and reduced transmembrane transport activities in IVC embryos that may lead to reduced developmental potential. IVR embryos had lower activities in metabolic and biosynthetic processes but increased cellular signaling and transmembrane transport, suggesting these cellular mechanisms may contribute to improved blastocyst development compared to IVC embryos. However, the IVR embryos had compromised development compared to IVV embryos with notably over-active transmembrane transport activities that impaired ion homeostasis.
在单细胞水平上对牛囊胚转录组进行分析，使我们能够揭示第一次细胞谱系分离，在此过程中鉴定了内细胞团（ICM）、滋养外胚层（TE）和未定义的过渡细胞群。通过比较体内（IVV）、传统培养（IVC）和优化的低营养培养（IVR）获得的囊胚的转录组，我们发现 IVC 和 IVR 胚胎中 ICM 的细胞命运决定出现延迟。IVV、IVC 和 IVR 胚胎之间的发育潜力差异主要由 ICM 和过渡细胞贡献。对这些非 TE 细胞在组间的途径分析表明，IVC 胚胎中代谢和生物合成过程高度活跃，细胞信号减少，跨膜转运活性降低，这可能导致发育潜力降低。IVR 胚胎的代谢和生物合成过程活性较低，但细胞信号和跨膜转运增加，表明与 IVC 胚胎相比，这些细胞机制可能有助于改善囊胚发育。然而，与 IVV 胚胎相比，IVR 胚胎的发育受到损害，其跨膜转运活性明显过度活跃，破坏了离子平衡。
