Abstract
AbstractThe appropriate growth of the neurons, accurate organization of their synapses, and successful neurotransmission are indispensable for sensorimotor activities. These processes are highly dynamic and tightly regulated. Extensive genetic, molecular, physiological, and behavioural studies have identified many molecular players and investigated their roles in various neuromuscular processes. In this paper, we show that Beadex (Bx), theDrosophilaLIM only (LMO) protein, is required for motor activities and neuromuscular growth ofDrosophila.Bx7, a null allele, adult flies are flightless, with reduced walking and jumping activities. The larvae ofBx7, and the RNAi-mediated neuronal-specific knockdown ofBxshow drastically reduced crawling behaviour, a diminished synaptic span of the neuromuscular junctions and an increased spontaneous neuronal firing with altered motor patterns in the central pattern generators (CPGs). Microarray studies identified multiple targets of Beadex that are involved in different cellular and molecular pathways, including those associated with the cytoskeleton and mitochondria, that could be responsible for the observed neuromuscular defects. With genetic interaction studies, we further show thatHighwire(Hiw), a negative regulator of synaptic growth at the NMJs, negatively regulatesBx, as the latter’s deficiency was able to rescue the phenotype of theHiwnull mutant,HiwDN. Thus, our data indicates that Beadex functions downstream of Hiw to regulate the larval synaptic growth and physiology.
Publisher
Cold Spring Harbor Laboratory