Chronobiology
Author: Chiara Costa | Email: chcostapetrillo@gmail.com
Chiara Costa1°2°, Martina Radice1°2°, Esteban J. Beckwith1°2°, Nicolás Pírez1°2°
1° 1 Instituto de Fisiología, Biología Molecular y Neurociencias; UBA-CONICET, Argentina
2° Departamento de Fisiología, Biología Molecular y Celular; Facultad de Ciencias Exactas y Naturales; Universidad de Buenos Aires, Argentina.
To dissect the impact of social interactions on the circadian organization of locomotor activity of the fly Drosophila melanogaster, we performed experiments using two fly populations entrained to different light schedules, one advanced 6hs from the other. After a week of social interactions in constant darkness in a ratio 70:30, the activity of the flies was individually recorded during 4 days. We observed no differences in the phase of the locomotor activity peak after the interaction, and both groups kept their previous rhythmicity. These results suggest that in our experimental conditions the social context did not affect the circadian rhythm. To characterize the circadian clock of the pacemaker neurons at the molecular level, we analyzed in real time the oscillation of the clock protein TIM. For this purpose, we used genetically modified animals that present an insertion of the fluorescent reporter TOMATO in the clock protein TIM, allowing the analysis of the molecular clock by ex vivo confocal microscopy. We measured timTOMATO for a period of 24hs in the small ventral-lateral neurons (s-LNvs), the main pacemaker neuronal cluster in the fly brain. This experiment allowed us to observe if the phase of locomotor activity of the flies matches with the oscillation of proteins from the molecular clock in the pacemaker neurons.