2025/09/12 by Deirdre Hatton, Claire Marquilly, Caitlin Hanrahan +7 · 1 voice
Biochemistry, Genetics and Molecular Biology · Neuroscience · #Cellular transport and secretion #Neurobiology and Insect Physiology Research #Plant Reproductive Biology
paper · pdf · doi:10.1242/dev.204786
openalex publication_date 2025/09/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Dendrites form arbors whose size, shape and complexity define how neurons cover their receptive territories. Actin dynamics contribute to growth and remodeling of dendrite arbors. Here, we have examined how Spire, a conserved actin nucleation factor, promotes the formation of new branches in vivo. In live imaging of Drosophila class IV dendritic arborization (c4da) neurons, Spire was observed at new sites of branch initiation, where it assembled new actin polymer in a burst immediately before filopodial outgrowth. For dendrite arborization, Spire required intact structural domains to nucleate actin and target the secretory network, and interacted with Rab11 GTPase, a key regulator of recycling endosomes. Together, these findings support a model in which Spire cooperates with Rab11 to promote new dendrite branches by linking localized actin dynamics with intracellular trafficking of endosomes that deliver lipids and cargoes to fuel protrusive outgrowth of nascent dendrites.