What are the biological roles of non-coding RNA (ncRNAs)?

ncRNAs are involved in regulating various cellular processes. These processes include embryonic development, cellular differentiation, epigenetic regulation, and the modulation of gene expression.

During embryonic development, ncRNAs regulate gene expression through various mechanisms. These include microRNAs (miRNAs) targeting mRNAs for degradation and long noncoding RNAs (lncRNAs) modifying chromatin structure. NcRNAs also play pivotal roles in multiple aspects of embryogenesis, such as the transition from maternal to zygotic gene expression, organizing body axes, specifying cell types, maintaining pluripotency, and shaping organ morphogenesis. ncRNAs are essential for guiding cellular differentiation; during this process, ncRNAs regulate the expression of lineage-specific genes, directing cells towards specific cell fates. In epigenetic regulation, certain ncRNAs such as lncRNAs and Piwi-interacting RNAs (piRNAs) are involved in establishing and maintaining epigenetic marks that control gene expression. They can target specific genomic loci to induce changes in chromatin structure, thus influencing gene transcription. ncRNAs regulate gene expression at multiple levels, including transcriptional, post-transcriptional, and translational regulation. For example, lncRNAs can interact with chromatin-modifying complexes to regulate the transcriptional activity of target genes.