Dissecting the circuits that control circadian oviposition in Drosophila

SABRINA RIVA; GUADALUPE CASCALLARES; PAULA DRAUSAL; SEBASTIAN RISAU GUSMAN; PABLO GLEISER; M. FERNANDA CERIANI; D. LORENA FRANCO

Valparaiso

Simposio; XIV Latin American Symposium on Chronobiology; 2017

In Drosophila the circadianclock is controlled by interlocked transcriptional feedback loops present inneuronal and non-neuronal tissues. The oviposition or egg-layingbehavior is a physiological process that is under the control of thecircadian clock. The periodicity in oviposition is one of the less studiedrhythms in Drosophila and many important aspects related with the role ofthe molecular clock remain to be elucidated. We study the molecular clockparticipation on egg-laying behavior by analyzing oviposition in control fliesas well as in per and tim null mutants, which lack afunctional clock. In contrast to controls, no rhythmic oviposition was detectedin mutant flies. To test the neuronal control of oviposition, we downregulated per expression exclusively on neurons. Ourresults showed an arrythmic oviposition phenotype when per was downregulated in neurons. Furthermore,to elucidatethe central vs. peripheral control of circadian oviposition, we downregulated per expression in the brain smalllateral ventral neurons. Circadian oviposition was observed on mutant flies,indicating no role of these neurons on rhythmic egg-laying behavior. Furtherexperiments will be designed to dissect the role and hierarchy of differentcentral and peripheral neurons.