A BMP retrograde signal shapes a key circadian pacemaker circuit

GOROSTIZA, EA; CERIANI M.FERNANDA

JOURNAL OF NEUROSCIENCE

SOC NEUROSCIENCE

Lugar: Washington; Año: 2013 vol. 33 p. 687 - 696

0270-6474

The neuropeptide pigment-dispersing factor (PDF) synchronizes molecular oscillations within circadian pacemakers in the Drosophila brain. It is expressed in the small and large ventral Lateral Neurons (sLNvs and lLNvs), the former being indispensable for maintaining behavioral rhythmicity under free-running conditions. How PDF circuits develop the specific connectivity traits that endow such global behavioral control remains unknown. Here we show that mature sLNv circuits require PDF signaling during early development, acting through its cognate receptor PDFR at postsynaptic targets.  Yet, axonal defects by PDF knockdown are presynaptic and become apparent only after metamorphosis, highlighting a delayed response to a signal released early on. Postsynaptic expression of constitutively active bone morphogenetic protein (BMP) receptors prevents pdfr mutants miss-routing phenotype, while sLNv-restricted downregulation of BMP signaling components phenocopied pdf01. Thus, we have uncovered a novel mechanism that provides an early ?tagging? of synaptic targets that will guide circuit refinement later in development.