Post-Transcriptional and Translational Control of Eukaryotic Gene Expression, Select the letter from the key which BEST fits each statement below, regarding eukaryotic post-transcriptional and translational control.

Post-Transcriptional and Translational Control of Eukaryotic Gene Expression

Post-transcriptional and translational control of gene expression is a critical mechanism of gene regulation in eukaryotic cells. Post-transcriptional control refers to the modifications, processing and degradation of mRNA after transcription and before translation. Translational control is the regulation of protein synthesis from mRNA. Both post-transcriptional and translational control play important roles in gene regulation, allowing for the fine-tuning of gene expression. Post-transcriptional control can involve the splicing of introns from pre-mRNA, the processing of 5′ and 3′ untranslated regions (UTRs), the addition of a 5′ cap and 3′ poly-A tail, and the degradation of mRNA molecules. These processes influence the stability, localization and translation of mRNA. For example, the presence of certain UTRs can influence the translation rate of mRNA (Komarova et al., 2016). In addition, the presence of specific elements in the 3′ UTR can affect mRNA decay rates (Wang et al., 2018). Translational control is mainly achieved through the binding of regulatory proteins to mRNA at the initiation stage of protein synthesis. These regulatory proteins can either stimulate or repress translation, depending on the context. For example, specific microRNAs can regulate translation through the binding to the 3′ UTRs (Liu et al., 2019). Cont…