In: Biology
You experimentally mutagenize mammalian cells and identify a mutant in which spliced mRNAs accumulate in the cytoplasm but are not translated by ribosomes. you find that the small and large ribosomal subunits are themselves not defective. propose a gene that may be disrupted to cause this phenotoype. explain.
Spliced mRNAs are the final mRNA from which translation can take place.
Small and large ribosomal subunits are made up of rRNA. So rRNA are produced efficiently.
It seems that there is mutation in tRNA genes. As a result no one can carry amino acid to the ribosome for translation (protein synthesis).
There are several reasons for which translation may not take place :
1. Absence of strat codon
2. Absence of the enzyme that load amino acid to the tRNA
3. Absence of the protein factors that help to assemble small and large subunits of ribosome