Pre-mRNA Processing: A Crucial Step in Gene Expression Regulation

What is the initial transcript synthesized during transcription in eukaryotic cells?

A. mRNA

B. tRNA

C. pre-mRNA

D. rRNA

Answer:

Pre-mRNA has to be "tailed" before it migrates to the cytoplasm, option C is correct.

Pre-mRNA is the initial transcript synthesized during transcription in eukaryotic cells. Before it can be transported from the nucleus to the cytoplasm for translation, the pre-mRNA molecule undergoes a process called RNA processing or RNA splicing. This process involves the removal of non-coding regions called introns and the joining together of coding regions called exons. Once the pre-mRNA has undergone splicing, it is converted into mature mRNA, which can then be transported to the cytoplasm for translation.

Pre-mRNA processing is a crucial step in gene expression regulation in eukaryotic cells. After transcription, the pre-mRNA molecule contains both introns and exons. Introns are non-coding regions that do not contain instructions for protein synthesis, while exons are the coding regions that contain the protein-coding sequences. This process ensures that only the necessary protein-coding sequences are included in the final mRNA molecule.