Cytologically, heterochromatin is defined as condensed chromosomal regions that are differentially stained, while molecularly, it has a broad impact on chromosome segregation, recombination and gene expression. Transposable elements are an integral part of heterochromatin in most if not all eukaryotes, but their role in chromatin modification is poorly understood. We will examine the proposition that heterochromatin silences genes by virtue of transposon mediated gene regulation, using Arabidopsis thaliana and the fission yeast S. pombe as model systems. We will use genomic tiling microarrays to assay DNA and histone modification, as well as transcription, along Arabidopsis chromosome 4. We have demonstrated that the chromatin remodeling mutant decrease in DNA methylation 1 (ddml) has major effects on the relative distribution of histoneH3 methylated on lysine 4 and lysine 9 in an isolated, transposon-laden region of heterochromatin. We will use forward and reverse mutagenesis to identify novel loci that have similar effects on different classes of transposons. In fission yeast, we have shown that heterochromatic centromere repeats are transcribed, and that the transcripts are substrates for RNA interference. Mutants in RNAi are defective in centromere silencing and function, and they fail to recruit histone H3 methyl lysine 9 (a hallmark of heterochromatin) to the centromeric repeats. We will investigate the molecular and cytological basis for this effect in fission yeast. Preliminary data suggests this mechanism is conserved in Arabidopsis. We will use each system to explore the ancient role of heterochromatin in chromosome biology.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM067014-04
Application #
7100282
Study Section
Genetics Study Section (GEN)
Program Officer
Carter, Anthony D
Project Start
2003-08-01
Project End
2008-07-31
Budget Start
2006-08-01
Budget End
2008-07-31
Support Year
4
Fiscal Year
2006
Total Cost
$331,034
Indirect Cost
Name
Cold Spring Harbor Laboratory
Department
Type
DUNS #
065968786
City
Cold Spring Harbor
State
NY
Country
United States
Zip Code
11724
Borges, Filipe; Parent, Jean-Sébastien; van Ex, Frédéric et al. (2018) Transposon-derived small RNAs triggered by miR845 mediate genome dosage response in Arabidopsis. Nat Genet 50:186-192
Underwood, Charles J; Choi, Kyuha; Lambing, Christophe et al. (2018) Epigenetic activation of meiotic recombination near Arabidopsis thaliana centromeres via loss of H3K9me2 and non-CG DNA methylation. Genome Res 28:519-531
Underwood, Charles J; Henderson, Ian R; Martienssen, Robert A (2017) Genetic and epigenetic variation of transposable elements in Arabidopsis. Curr Opin Plant Biol 36:135-141
Ziolkowski, Piotr A; Underwood, Charles J; Lambing, Christophe et al. (2017) Natural variation and dosage of the HEI10 meiotic E3 ligase controlArabidopsiscrossover recombination. Genes Dev 31:306-317
Chomet, Paul; Martienssen, Rob (2017) Barbara McClintock's Final Years as Nobelist and Mentor: A Memoir. Cell 170:1049-1054
Schorn, Andrea J; Gutbrod, Michael J; LeBlanc, Chantal et al. (2017) LTR-Retrotransposon Control by tRNA-Derived Small RNAs. Cell 170:61-71.e11
Ingouff, Mathieu; Selles, Benjamin; Michaud, Caroline et al. (2017) Live-cell analysis of DNA methylation during sexual reproduction in Arabidopsis reveals context and sex-specific dynamics controlled by noncanonical RdDM. Genes Dev 31:72-83
Quadrana, Leandro; Bortolini Silveira, Amanda; Mayhew, George F et al. (2016) The Arabidopsis thaliana mobilome and its impact at the species level. Elife 5:
Fransz, Paul; Linc, Gabriella; Lee, Cheng-Ruei et al. (2016) Molecular, genetic and evolutionary analysis of a paracentric inversion in Arabidopsis thaliana. Plant J 88:159-178
Borges, Filipe; Martienssen, Robert A (2015) The expanding world of small RNAs in plants. Nat Rev Mol Cell Biol 16:727-41

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