IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
DPP signaling contributes to set basic properties of the PDF circuit in Drosophila
Autor/es:
ESTEBAN J. BECKWITH; JIMENA BERNI; M. FERNANDA CERIANI
Lugar:
Destin
Reunión:
Congreso; 12th Biennial Meeting Society for Research on Biological Rhythms; 2010
Institución organizadora:
Society for Research on Biological Rhythms
Resumen:
Living organisms use circadian rhythms to maintain internal temporal order and anticipate daily environmental changes. Clocks employ self-sustained biochemical oscillators and manifest at molecular, physiological and behavioral levels. In Drosophila, a group of neuronsexpressing the Pigment Dispersing Factor (PDF) represent the “central oscillator” of the fly brain.As a result of a missexpression screen using the GAL4/UAS system we identified a fly strain that causes period lengthening of the daily activity rhythms. The transposon landed within schnurri (shn), a nuclear component of the decapentaplegic (dpp) pathway. shnoverexpression in the PDF circuit was necessary and sufficient to generate a 25.5h period of locomotor behavior. Interestingly, constitutive overexpression of activated receptors that initiate the DPP signalling cascade also gave rise to long period phenotypes, in agreementwith those observed upon shn overexpression. In contrast, downregulation of the endogenous receptors also impacted circadian rhythmicity leading to arrhythmicity A detailed analysis of PER subcelular localization showed a delayed PER nuclear entry in the mutantcompared to that of wild type flies, pointing to a specific effect of shn deregulation on the core clock mechanism. shn overexpression in the PDF circuit led to a reduction in the PDF inmunoreactivity at the dorsal termini, which is not due to transcriptional downwnregulation.Concomitantly, shn overexpression associated efects in the structure of the PDF circuit accompanied by a defect in the branching phenotype that leading to shorter circuits.Recently, the DPP pathway has been shown to operate as a retrograde signal that sets synaptic properties and, in combination with other cellular clues, establishes the peptidergic fate of a specific circuit in the fly brain. Ongoing experiments will explore whether this pathwayis relevant in the assembly and maintenance of PDF circuit integrity.