GSE210559
Diurnal small RNA expression and post-transcriptional regulation in young and old Drosophila melanogaster heads
MicroRNAs are a class of small (~22nt) endogenous RNAs that regulate target transcript expression post-transcriptionally. Previous studies characterized age-related changes in diurnal transcript expression but it is not understood how these changes are regulated, and whether they may be attributed in part to changes in microRNA expression or activity with age. Diurnal small RNA expression changes with age were not previously studied. To interrogate changes in small RNA expression with age, we collected young (5 day) and old (55 day) Drosophila melanogaster around-the-clock and performed deep sequencing on size-selected RNA from whole heads. We find several microRNAs with changes in rhythmicity after aging, and we investigate microRNAs which are differentially expressed with age. We find that predicted targets of differentially expressed microRNAs have RNA-binding and transcription factor activity. We use a previously published method to identify mRNA transcripts which show evidence of microRNA targeting that is altered after aging, and find several that are involved in muscle development and maintenance. Finally, we identify novel microRNAs using the random-forest-based method miRWoods, which surprisingly also discovered transfer RNA-derived fragments. Overall design: RNA-sequencing and analysis of small RNA from Drosophila melanogaster heads, collected every 4 hours over 24 hours