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Effect of Gnmt overexpression on rhythmic gene expression in Drosophila melanogaster photoreceptor cells

ABSTRACT: Nearly half of the genes in the eye are regulated through the molecular circadian clock, a transcription-translation feedback loop that is governed by environmental stimuli. In aging, vision loss correlates with perturbations to the circadian clock. Rhythmic gene expression is substantially altered in the aging Drosophila melanogaster eye in that over 1/3 of genes have differential rhythmic expression. H3K4me3 is important for transcriptional activation of genes regulated by the circadian clock and is globally decreased in aging photoreceptors. It is unknown what mechanism underlies decreased H3K4me3. Glycine-N-methyltransferase (Gnmt) regulates the availability of the universal methyl donor S-adenosyl methionine (SAM) by methylating glycine to produce sarcosine and S-adenosylhomocysteine (SAH), a potent inhibitor of histone methyltransferase activity. Both Gnmt and SAH are increased in the aging eye, therefore we hypothesize that an age-dependent increase of Gnmt contributes to disruption of rhythmic gene expression. To test this hypothesis, nuclear RNA-seq was performed on photoreceptor nuclei that were collected every four hours from flies outcrossed to wild type or with overexpression of either active or partially active Gnmt

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE267056 | GEO | 2026/03/16

REPOSITORIES: GEO

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