PUBLIC LECTURE: Epigenetics Explained

Tremendous progress has been made in our understanding of genetics over the last century.

This lecture will discuss the groundbreaking ideas of Mendel and Darwin, Watson and Crick’s search for the molecular basis of genetics and the recent sequencing of the human genome.

The challenge now is to understand how the DNA sequence shapes our physical appearance. Phenotype results from the interaction between genotype and environment. However, in laboratory animals where genetic variability is reduced (by using inbred strains) and environmental influences are standardised, random variation in biological traits is still observed. This has been termed “intangible variation” or “developmental noise”. Up to 80% of phenotypic variability in mouse body weight has been found to be caused by a component other than genotype or environment (Gartner, 1990). Although it is thought that this variability is established in early development, its origin is unknown. We propose that the molecular basis of developmental noise lies in the epigenetic state of the genome.

Epigenetics is the study of heritable changes in gene expression that occur without a change in DNA sequence. The field of epigenetics, introduced by Waddington in the 1940s, is undergoing a renaissance. Recent advances in this discipline will be discussed in this lecture.