Epigenetics and DNA Methylation
Genetics & Genomics
1975
Discoverers: Robin Holliday, Arthur Riggs
Overview
Proposal that methylation of cytosine bases in DNA can regulate gene expression without altering the underlying sequence, introducing epigenetic inheritance.
Significance
Demonstrated that gene activity can be heritably modified by chemical marks, explaining phenomena like X-chromosome inactivation and genomic imprinting.
Methodology
Biochemical analysis of 5-methylcytosine distribution and restriction enzyme sensitivity patterns in mammalian DNA.
Impact
- Explained heritable gene silencing
- Linked environmental factors to gene expression changes
- Opened the field of epigenomics