In Df(1)Ten-a homozygous mutant adults, the antennal lobe glomeruli VA1lm and Dl4 display morphological defects in a majority and a minority of cases, respectively, and the associated olfactory receptor neurons (or47b neurons in the case of the glomerulus Va1lm) show significant decreases in the number and density of pre-synaptic sites, as assessed by an active zone marker, despite of similar axon volume, as compared to controls; the adult antennal lobe projection neurons DA1 lPN and VA1d adPN present significant decreases in the number and density of post-synaptic sites, but similar dendrite volume, as compared to controls; antennal lobe glomeruli neurons present a significant reduction in the average numbers of T-bars, the majority of which also display morphological defects, including continuous, multiple, membrane-detached and misshapen T-bars.

Homozygous viable.

Homozygous DA1 projection neurons (generated using MARCM) show mismatching of their dendrites with Or47b-expressing olfactory receptor neuron (ORN) axons. Homozygous VA1d/DC3 projection neurons (generated using MARCM) do not show mismatching of their dendrites to Or47b-expressing ORN axons.

Bouton number at the neuromuscular junction is reduced compared to controls in mutant larvae. Defects in T-bar ultrastructure, membrane organisation and apposition to contractile tissues are seen. The mean amplitude of the evoked excitatory postsynaptic potentials (EPSPs) is decreased by 28% in mutant larvae. Spontaneous miniature EPSPs show a 20% decrease in amplitude and a 46% decrease in frequency compared to wild type. These defects result in a 20% reduction in quantal content compared to controls.