Scientists Unveil RNA-Guided Mechanisms Driving Cell Fate
Published:26 Jul.2023 Source:Monash University
Researchers have characterised a critical time in mammalian embryonic development using powerful and innovative imaging techniques. Just a few days into the journey of embryogenesis, when turning into 16 cells, the embryo must make its first difficult decision -- which of its cells will give rise to the embryo or will become extra-embryonic tissue, for example, placenta. In this study, the research team has discovered how this decision-making process is facilitated by capturing the inner organisation of single cells of the early embryo.
Ribonucleic acid, RNA, plays a key role here. At the 16-cell stage, the different subtypes of RNA, named rRNAs, mRNAs and tRNAs, are sorted to the two ends of a cell called apical and basal side. The distribution of RNA subtypes determines what the next generation of cells of the embryo will become. Interestingly, while most mRNAs and tRNAs remain parked at the apical side, most rRNA molecules travel down to the basal side hitchhiking on organelles called lysosomes.
The crowded basal side is occupied predominantly with rRNAs. Daughter cells obtaining the more active protein factories of the apical side, are more transformable and specialise into the future placenta. This decision and many like it, which is known as cell fate, are important in development as it determines how these early cells reach their final cell type, such as skin cells, heart muscle cells and brain cells. As in real life, cells can influence the direction of their own future by getting organised early.