Rhythmic expression of the cycle gene in a hematophagous insect vector

Area of Science:

• Chronobiology
• Molecular Biology
• Vector Biology

Background:

• Circadian clocks enable organisms to adapt to environmental cycles.
• In Drosophila, the cycle gene is crucial for the molecular clock's feedback loops.
• The molecular clock in insect vectors remains poorly understood.

Purpose of the Study:

• To investigate the sequence, genomic organization, and circadian expression of the cycle gene in the sandfly Lutzomyia longipalpis.
• To compare the cycle gene's characteristics in sandflies with those in Drosophila melanogaster.

Main Methods:

• Sequence analysis of the cycle gene in Lutzomyia longipalpis.
• Analysis of genomic organization and circadian expression patterns.
• Comparison of deduced amino acid sequences and expression profiles with Drosophila.

Main Results:

• Sandfly cycle gene encodes a protein with a conserved C-terminal transactivation domain, absent in Drosophila.
• An alternative transcript form was identified in sandflies.
• Cycle gene expression is rhythmic in sandfly heads (males and females) but constitutive in female bodies, contrasting with constitutive expression in Drosophila.

Conclusions:

• The cycle gene in Lutzomyia longipalpis displays distinct features compared to Drosophila.
• These differences suggest that hematophagous vectors may serve as novel models for insect circadian clock research.