The mechanisms that determine the organization and function of specific domains within chromatin
are still largely unclear. Plants have diversified the number of core histone H2A variants. These
variants index the major types of chromatin and our unpublished data has established that each H2A
variant combines with a specific set of histone modifications to define distinct chromatin states.
Computational analyses suggest that these chromatin states tightly control genomic functions. Here,
we propose to investigate the role of H2A variants in organizing chromatin states and regulating their
function. To answer this question using Arabidopsis we will first compare standard chromatin states
in somatic cells with reproductive cell types, which lack specific H2A variants. We will also study the
impact of the loss of specific H2A variants on chromatin states using specific genetic backgrounds in
Arabidopsis and a molecular evolutionary strategy based on model species of alga and bryophytes.
This project will establish how and to what degree H2A variants organize chromatin into functional
domains of the genome.
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