The increased number of boutons on neuromuscular junctions observed in third instar larvae heterozygous for any of the following alleles: Arpc1Q25sd, Arpc1Q25st or Blos1ex65 is restored to wild-type levels in both Arpc1Q25sd/+;Blos1ex65/+ and Arpc1Q25st/+;Blos1ex65/+ double heterozygotes.
The reduced number of dendritic branches in class IV dendritic arborizing neurons characteristic for Blos1ex65 heterozygous larvae is mildly enhanced in Blos1ex65;Arpc1Q25sd double heterozygotes but the total dendrite length per neuron remains unchanged.
One copy of Dysbe01028 suppresses the dominant changes in mEJP amplitude and quantal content seen in Blos1ex65/+ mutant NMJs. The increase in bouton number seen in Blos1ex65/+ NMJs is also suppressed. Dysbe01028 Blos1ex65 double heterozygotes exhibit deficits in short term olfactory habituation. This phenotype is not observed in either heterozygote alone.