bims-ciryme 2023-01-29 papers

Issue of 2023‒01‒29
two papers selected by
Gabriela Da Silva Xavier
University of Birmingham

Proc Natl Acad Sci U S A. 2023 Jan 31. 120(5): e2217532120

The microbiome stabilizes circadian rhythms in the gut.

Yueliang Zhang, Yongjun Li, Annika F Barber, Sara B Noya, Julie A Williams, Fu Li, Scott G Daniel, Kyle Bittinger, Jichao Fang, Amita Sehgal.

The gut microbiome is well known to impact host physiology and health. Given widespread control of physiology by circadian clocks, we asked how the microbiome interacts with circadian rhythms in the Drosophila gut. The microbiome did not cycle in flies fed ad libitum, and timed feeding (TF) drove limited cycling only in clockless per01 flies. However, TF and loss of the microbiome influenced the composition of the gut cycling transcriptome, independently and together. Moreover, both interventions increased the amplitude of rhythmic gene expression, with effects of TF at least partly due to changes in histone acetylation. Contrary to expectations, timed feeding rendered animals more sensitive to stress. Analysis of microbiome function in circadian physiology revealed that germ-free flies reset more rapidly with shifts in the light:dark cycle. We propose that the microbiome stabilizes cycling in the host gut to prevent rapid fluctuations with changing environmental conditions.

Keywords: circadian phase shifts; circadian rhythms; gut microbiome; timed feeding; transcriptome

DOI: https://doi.org/10.1073/pnas.2217532120

Proc Natl Acad Sci U S A. 2023 Jan 31. 120(5): e2214883120

Time series transcriptome analysis implicates the circadian clock in the Drosophila melanogaster female's response to sex peptide.

Sofie Y N Delbare, Sara Venkatraman, Kate Scuderi, Martin T Wells, Mariana F Wolfner, Sumanta Basu, Andrew G Clark.

Sex peptide (SP), a seminal fluid protein of Drosophila melanogaster males, has been described as driving a virgin-to-mated switch in females, through eliciting an array of responses including increased egg laying, activity, and food intake and a decreased remating rate. While it is known that SP achieves this, at least in part, by altering neuronal signaling in females, the genetic architecture and temporal dynamics of the female's response to SP remain elusive. We used a high-resolution time series RNA-sequencing dataset of female heads at 10 time points within the first 24 h after mating to learn about the genetic architecture, at the gene and exon levels, of the female's response to SP. We find that SP is not essential to trigger early aspects of a virgin-to-mated transcriptional switch, which includes changes in a metabolic gene regulatory network. However, SP is needed to maintain and diversify metabolic changes and to trigger changes in a neuronal gene regulatory network. We further find that SP alters rhythmic gene expression in females and suggests that SP's disruption of the female's circadian rhythm might be key to its widespread effects.

Keywords: Drosophila; circadian rhythm; gene regulatory network; sex peptide; time-course RNA-seq

DOI: https://doi.org/10.1073/pnas.2214883120