A conserved odor detection pathway via modulation of chromatin and cellular gene expression

ABSTRACT: Odorants in the environment that can cross the cell membrane are likely important detection targets for a conserved pathway and using one such odorant, diacetyl, we show that the ancient family of histone deacetylase enzymes (HDACs) can act as an atypical odorant detection pathway. Based on our testing we demonstrate that this response meets 6 characteristics of an odor-sensing pathway to odorant exposure: (1) a highly specific response to volatile compounds by altering gene expression, (2) differential modulation of different HDACs, (3) dose-dependent response in vitro, (4) dose-dependent response in vivo, (5) reversible to some degree, and (6) highly conserved across eukaryotes such as invertebrates, vertebrates and plants. We observe that exposure to diacetyl vapors modulates gene expression over a period of days in the Drosophila antenna. The up-regulated genes significantly overlap with genes altered by known histone deacetylase inhibitors administered in the food. In vitro assays with purified human proteins showed that different members of class I HDACs are differentially inhibited. Moreover exposure to diacetyl increased histone H3K4 acetylation in a human cell line. Organisms spanning multiple taxa can respond to diacetyl volatiles by altering gene expression, presumably in part via inhibition of histone deacetylase proteins causing epigenetic changes. Our finding reveals a highly conserved and slow-acting pathway for responding to odorants beyond the fast-acting neuronal activation via transmembrane receptors, and raises questions about the effects of this odorant detection pathway on physiology and health of organisms.

ORGANISM(S): Mus musculus Arabidopsis thaliana Drosophila melanogaster

PROVIDER: GSE116502 | GEO | 2020/07/28

REPOSITORIES: GEO