Assaying the Drosophila negative feedback loop with RNA interference in S2 cells

Area of Science:

• * Molecular biology
• * Chronobiology
• * Genetics

Background:

• * Circadian rhythms are governed by transcriptional negative feedback loops, essential for molecular and behavioral oscillations.
• * In Drosophila, CLOCK/CYCLE (CLK/CYC) activate period (per) transcription, while PER protein represses it.
• * PER phosphorylation by Doubletime (DBT) and casein kinase II (CKII) influences stability and nuclear localization, impacting rhythmicity.

Purpose of the Study:

• * To investigate the role of DBT and CKII in PER-mediated transcriptional repression.
• * To establish and utilize the Drosophila S2 cell line with RNA interference (RNAi) for studying gene expression.
• * To differentiate direct repression effects from indirect subcellular localization effects.

Main Methods:

• * Employed Drosophila S2 cell line for studying PER repression activity.
• * Utilized RNA interference (RNAi) to knock down specific gene expression.
• * Applied immunocytochemistry and leptomycin treatment to analyze subcellular localization and direct repression effects.

Main Results:

• * Established protocols for PER repression assays in S2 cells using RNAi.
• * Developed methods to distinguish direct transcriptional repression from indirect effects on protein localization.
• * Discussed the generation of stable S2 cell lines for future research.

Conclusions:

• * The study provides a framework for dissecting the molecular mechanisms of circadian gene regulation in Drosophila.
• * The methods described enable detailed analysis of protein function in transcriptional repression and localization.
• * Stable S2 cell lines will facilitate further investigation into the components of circadian feedback loops.