Chromatin genes and disease

Published on September 3, 2014   34 min

Other Talks in the Series: Molecular Genetics of Human Disease

This talk is on chromatin genes and disease. And my name is Richard Gibbons. And I'm a clinical geneticist and molecular biologist working in the MRC molecular hematology unit, and the Weatherall Institute of Molecular Medicine, which is part of the University of Oxford. My particular interests are in how genes are regulated. That's how they're turned on and off. And in the field of epigenetics.
So what does this term mean? It accounts for differences in the phenotype type of cells, or organisms that are genetically identical. It's involved in alterations in gene expression. And also, the important thing is, this pattern of gene expression is maintained on cell division.
For instance, these different organisms here, the caterpillar, the chrysalis, and the butterfly, are genetically identical. But they're phenotypically different.
Here we see a tortoiseshell cat. And the different coat color it has, the orange and black stripes, are from cells that are genetically identical, but they produce the different colors. And this is because the coat color genes are on the X chromosome, although this female has two X chromosomes. And in any one cell, any one of those Xs is active. It's called X inactivation. So if the paternal X encodes for the black color, and maternal X encodes for the orange color, in any one cell, only one will be active. And the progeny of those cells will have the same pattern. So you give rise to this mosaic pattern of coloring, depending on which X is active. But the important thing is, those cells are genetically identical, but epigenetically different.