The technique of Western blotting can be used to detect proteins that are translated from a particular mRNA. This method is described in Chapter 20 and also in experimental question E5.
Let's suppose a researcher was interested in the effects of mutations on the expression of a protein-encoding gene that encodes a protein we will call protein X. This protein is expressed in skin cells and contains 572 amino acids. Its molecular mass is approximately 68,600 Da, or 68.6 kDa. Make a drawing that shows the expected results of a Western blot using proteins isolated from the skin cells obtained from the following individuals:
Lane 1: A normal individual
Lane 2: An individual who is homozygous for a deletion, which removes the promoter for this gene
Lane 3: An individual who is heterozygous in which one gene is normal and the other gene has a mutation that introduces an early stop codon at codon 421
Lane 4: An individual who is homozygous for a mutation that introduces an early stop codon at codon 421
Lane 5: An individual who is homozygous for a mutation that changes codon 198 from a valine codon into a leucine codon