Question: How has the analysis of genetic mutants been used in the study of DNA repair pathways? Use specific examples in your answer

Expert answer

SECTION B QUESTION 1.1 BRIEF ANSWER: The analysis of genetic mutants has been used extensively in the study of DNA repair pathways. For example, mutations in the genes encoding the proteins involved in DNA repair can lead to increased susceptibility to cancer. In addition, mutations in these genes can also affect the efficiency of DNA repair and thus influence the outcome of treatment with DNA-damaging agents such as chemotherapy drugs.

Section A QUESTION 1.2 BRIEF ANSWER: DNA methylation is a chemical modification of DNA that can have a profound impact on gene expression. Methylation can silence genes, making them inaccessible to the proteins that normally switch them on or off. This process is thought to play an important role in cancer, as well as a range of other diseases.

Recent advances in DNA sequencing technology have allowed researchers to map the methylation patterns of entire genomes. This has revealed that methylation is much more widespread than previously thought, and that it plays a role in many different biological processes.

Methylation also appears to be involved in human genetic disease. For example, mutations in the gene MECP2 are known to cause Rett syndrome, a severe neurological disorder. These mutations lead to changes in methylation patterns, which in turn disrupt the normal function of MECP2.

While the role of DNA methylation in human disease is still being elucidated, it is clear that this process plays a significant role in many different disorders. Understanding the mechanisms by which methylation affects gene expression will be crucial for developing new treatments for these conditions.