BME 130 – Genomes
Lecture 19
The histone code
Figure 7.1 Genomes 3 (© Garland Science 2007)
Figure 10.13 Genomes 3 (© Garland Science 2007)
H3H4H2AH2B
CHiP-Seq
DNADNA-binding proteins
(histones, e.g)
crosslink
Immuno-precipitate and fragment DNA
Immuno-precipitateand fragment DNA
Reverse cross-links and sequence
ChIP-Seq and ChIP-chip comparison of two histone marks
Lower background & tighter peaks in ChIP-Seq (better contrast)
trxG(activation)
PcG(repression)
Promoter classeshigh CpG
gene
gene
genelow CpG
intermediate CpG
CpG
Highly expressed, housekeeping genes; other genesN=11,410
Genes with high tissue-specificityN=3,014
Mixture of genesN=3,338
NPC=neural progenitor cells MEF=embryonic fibroblastsES = embryonic stem cells
Highly dynamic histone modification during differentiation
H3K36me3 marks gene bodies (may prevent aberrant transcriptional initiation)
Imprinting is reflected in H3K36me3 state
Nucleosome positioning and gene structure
Histone modification in cell division
HaspinH3 H3
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plex A
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