066 | Exploring the contribution of circadian structural plasticity to seasonal adaptation


Author: Micaela Rodríguez Caron | Email: mmicarodrigueez@gmail.com

Micaela Rodríguez-Caron , Ivana L. Bussi , M. Fernanda Ceriani

1° Fundación Instituto Leloir – Instituto de Investigaciones Bioquímicas de Buenos Aires

Daily rhythms in animal physiology are typically coordinated by central pacemakers located within the brain, which involve a dozen of so-called clock genes. In Drosophila melanogaster, clock genes are expressed in 150 neurons that are clustered in functional groups according to their anatomical location and transcriptional profiling. Under constant conditions, circadian activity largely depends on the activity of the small lateral ventral neurons (sLNvs), which undergo circadian remodeling of their axonal projections. The morphology of their processes change throughout the day, displaying a highly elaborated arbor in the subjective morning and a less branched structure in the early subjective night. Thus, structural plasticity could modify the way in which the network is wired, but how these changes contribute to network response to environmental challenges and which are the molecular mechanisms underlying this process is less clear. If structural plasticity were recruited to mediate the adjustment to a changing photoperiod, a phase-locked relationship between the molecular clock and this cellular output would be anticipated. To explore the relationship between photoperiodic adaptation and structural remodeling we analyzed the profile of wild type flies at the molecular, cellular and behavioral levels. This approach uncovered an unexpected connection between light and structural plasticity that was further dissected under different light and temperature paradigms.