Final answer:
Pre-mRNA is not suitable for an in vivo translation assay because it requires modifications like 5' capping, 3' polyadenylation, and splicing to become mature mRNA, which is necessary for stability and proper translation by ribosomes.
Step-by-step explanation:
Pre-mRNA is not directly useful for an in vivo translation assay because it has not undergone the necessary post-transcriptional modifications that are required for stability and proper function. In eukaryotes, pre-mRNA must undergo 5' capping, 3' polyadenylation, and splicing to remove introns before it can be exported from the nucleus and used as a template for protein synthesis. Only mature mRNA that has been processed is suitable for translation by ribosomes.
In an in vivo translation assay, these modifications are critical for the mRNA to be recognized by the ribosomes and for the initiation of translation at the correct starting point. Additionally, the modifications help to stabilize the mRNA molecule and protect it from degradation, ensuring that it remains intact for efficient translation. The use of pre-mRNA would likely result in nonsense or incomplete protein products, if translated at all.
Eukaryotic translation involves various factors including mRNA, ribosomes, tRNAs, and enzymes. Translation begins at the 5' cap and proceeds at the initiation AUG codon, further emphasizing the importance of full mRNA maturation for a successful in vivo translation assay.