Slowpoke functions in circadian output cells to regulate rest:activity rhythms

Area of Science:

• Chronobiology
• Neuroscience
• Molecular Biology

Background:

• The circadian system regulates ~24-hour biological rhythms via central clock neurons.
• Circadian rhythms require output pathways to transmit timing information to downstream neurons.
• The Drosophila pars intercerebralis (PI) is a key circadian output center.

Purpose of the Study:

• To identify genes involved in circadian output pathways.
• To investigate the role of the slowpoke (slo) potassium channel in circadian output.

Main Methods:

• Single-cell RNA sequencing (scRNAseq) of PI cells.
• Cell-specific RNA interference (RNAi) to knock down candidate genes in PI.
• Analysis of circadian rest:activity rhythms in Drosophila.

Main Results:

• scRNAseq identified potential circadian output genes in PI cells.
• Knockdown of the slo potassium channel in PI cells reduced circadian rhythm strength.
• Slo function in both clock neurons and PI output cells is necessary for robust rhythms.

Conclusions:

• The slo potassium channel plays a critical role in circadian output pathways, specifically within PI cells.
• Slo contributes to generating daily neuronal activity rhythms essential for circadian information flow.
• Circadian behavioral rhythms depend on the function of slo in multiple circuit components.