engleski

Environmental stimuli induce remodelling of heterochromatin in insects

Conversion of environmental signals into epigenetic information is widely thought to occur but as yet has been poorly studied. It is proposed that environmental signals affect genome function by inducing the change in the expression of molecules involved in chromatin remodelling via histone or DNA modifications. Being the major heterochromatin constituents in beetle genera Tribolium and Palorus (Coleoptera), satellite DNA sequences are supposed to play important roles in heterochromatin regulation and remodelling. Their expression is strongly induced by heat shock and increased level of satellite-derived siRNAs is accompanied by increase of repressive epigenetic modifications of histones within heterochromatin. Upon recovery from heat stress expression of satellite DNA-associated siRNAs as well as histone modifications are restored. It can be hypothesized that transient reorganization of heterochromatin upon heat shock promoted by satellite DNA-derived siRNAs represents a part of a physiological gene expression program activated under stress conditions in insects.

epigenetics; satellite DNA; gene regulation

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