Lecture23-24-2011-summer

Lecture23-24-2011-summer - Epigenetics; DNA, RNA and...

Info iconThis preview shows pages 1–21. Sign up to view the full content.

View Full Document Right Arrow Icon
Epigenetics; DNA, RNA and Histones
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Outline Historical Background Mechanisms of Epigenetics DNA methylation Histone codes non coding RNA More unknown
Background image of page 2
First use and re-define Conrad Waddington (1942) - the study of the relationship between genotype and phenotype
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
First use and re-define Robin Holliday (1987) - the changes in gene activity during development are generally referred to as epigenetic
Background image of page 4
First use and re-define Robin Holliday (1987) - the changes in gene activity during development are generally referred to as epigenetic Heritable changes?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
First use and re-define Robin Holliday (1994) - Nuclear inheritance which is not based on differences in DNA sequence
Background image of page 6
First use and re-define 90’s Heritable changes which are not explained by Mendelian genetics
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Non-Mendelian Genetics? Mendel’s Experiment on Hieracium (Hawkweed) was non-Mendelian - parthenogenesis (Nogler, 2006)
Background image of page 8
First use and re-define Wu & Morris (2001) - the study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chromatin history Walther Flemming coined term “chromatin” ca 1880 Described mitosis Subsequent work revealed that chromatin is composed of nucleic acid and protein Mendel rediscovered ca 1900
Background image of page 10
DNA is genetic material (Gonick & Wheelis, 1983)
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
DNA structure (1953) Hershey-Chase (1952) DNA is genetic material
Background image of page 12
Not just A, T, G, C ! Hotchkiss (1948) Existence of methylcytosine
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
DNA methylation as regulatory function Holliday & Pugh, 1975; Riggs, 1975 – DNA methylation as a regulatory function Clark et. al ., 1994 - the bisulphite method
Background image of page 14
DNA methylation as regulatory function (Issa, 2003) Roles in development, carcinogenesis, maintenance of heterochromatin etc.
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
DNA methylation as regulatory function Not all organisms have DNA methylation Major role in the regulation: Mammals, Neurospora No DNA methylation: S. cerevisiae, C. elegans Very little: Drosophila No developmental role: Arabidopsis (only generationally stable ones)
Background image of page 16
1970’s Nucleosome discovered Electron micrograph Felsenfeld (1976), Kornberg (1977), Olins (1978)
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chromatin in early 90s’ DNA Exciting Genetic material (encodes proteins) Short sequences bind regulatory proteins Histones Boring Package DNA in repetitive structure Interfere with transcription
Background image of page 18
Transcription factors can modify Histones Gcn5p, associated with activation, has histone acetyltransferase activity CBP co-activator is histone acetyltransferase - Bannister and Kouzarides, 1996 Rpd3p, associated with repression, has histone deacetylase activity - Taunton, Hassig, and Schreiber, 1996
Background image of page 19

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Histones
Background image of page 20
Image of page 21
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 140

Lecture23-24-2011-summer - Epigenetics; DNA, RNA and...

This preview shows document pages 1 - 21. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online