dnc1/dncM14 adults show a significant reduction in performance index in an aversive olfactory learning assay compared to control flies.
In contrast to wild type, type II neuromuscular junctions do not show an increase in the number of natural synaptopods in response to octopamine in homozygous third instar larvae.
dncM14 homozygous and dncM14/dncML heterozygous mutants exhibit an increase in the number of naturally occuring synaptopods at the type II endings. This increase is eliminated in a Dp(1;2)51b background.
Application of 10υM octopamine fails to increase the number of synaptopods in dncM14 homozygous neuromuscular junctions.
dncM14 mutants display decreased locomotor speed and no response to starvation.
dnc1/dncM14 mutant flies show decreased avoidance of high temperatures.
Nurse cell dumping is incomplete in egg chambers from homozygous and dnc2/dncM14 females. Egg chambers have severely truncated dorsal appendages or the dorsal appendages fail to form altogether. Egg chamber degeneration is detected in stage 6 egg chambers and by stages 10 and 11, 88% of egg chambers are degenerating. Homozygous females lay only an occasional egg.
Nurse cell nuclei are enlarged compared to wild type in dncM14/Df(1)N-64i16 and dnc225/dncM14 females. Rare egg chambers containing 32 cells are seen. Females show egg retention.
Synaptic terminals of axons 1 and 2 (from neurons RP3 and 6/7b respectively) at the neuromuscular junction of muscles 6 and 7 of third instar dncM14/Y larvae have less dense presynaptic and postsynaptic membranes than control synaptic terminals. A similar number of synapses per unit length of terminal is seen compared to controls. Axon 2 terminals show an increase in synapse size. A much greater variability in synapse area is seen compared to controls. The ratio of docked to undocked vesicles is higher than in wild type in axon 1 synapses.
Neurons with a slowly inactivating outward current and down-modulated by cAMP are absent in homozygous larval brains in contrast to wild-type. Neurons with an outward current dominated by a rapidly inactivating outward current and not modulated by cAMP are more abundant in homozygous larval brains compared to wild-type.
The RP3 and 6/7b neurons which innervate longitudinal muscles 6 and 7 have overgrown terminals in dncM14 mutant larvae and establish a larger terminal surface over the muscles than in wild-type larvae.
Virgin females injected with sex peptide (SP) show no decline in receptivity towards courting males, no inhibition of remating associated with the transfer of any non-sperm components at mating (the 'copulation effect') but did show a loss of receptivity due to the receipt of sperm (the 'sperm effect'). There is no significant difference in lifespan between females that have mated once and virgin females. Twice mated females have a significantly shorter lifespan.
Increased bouton number and branching (due to down-regulation of synaptic Fas2 expression) and an increase in quantal content. Expression of CrebB-17Ab.hs does not alter the increase in synaptic structure but does reduce the quantal content to wild type levels. Another characteristic of the dnc phenotype is an alteration of synaptic modulation, wild type facilitation is replaced by depression at stimulation frequencies above 10Hz. Expression of CrebB-17Ab.hs significantly suppresses this aspect of the phenotype.
Mutant increases cAMP synthesis and moderately increases the rate of habituation (using the jump-and-flight escape response). Habituation is extremely rapid in dnc rut double mutants.
Growth cone exploratory movement is nearly arrested. Phenotype can be mimicked by normal neurons when perfused with db-cAMP (dibutyryl cAMP) or forskolin. Motility is also restored by counterbalancing the effects in rut dnc double mutants.
Number of boutons is increased compared to wild type due to reduction in Fas2 expression, but the mean quantal content or the quantal size is not altered reflecting no change in synaptic strength. Bouton number does not increase when Fas2Scer\UAS.cLa is expressed from Scer\GAL4E62-2 in dncM14 larvae.
Heterozygotes with dnc64j15 and dnc69h9 display reduced female fertility, numerous eggs laid generating some progeny. Heterozygotes with dnc81l6 are female sterile, no eggs are laid.
The voltage-activated transient K+ current (IA) in the larval muscle fibres of dncM14 animals is increased compared to wild-type. The amplitude of the transient and delayed plateau outward K+ currents (IT and IS respectively) in the larval muscle fibres of dncM14 animals are increased compared to wild-type. The amplitude of these currents is drastically reduced, to almost normal levels, if the fibres are treated with caffeine.
Transheterozygote females dncM14/rut2 and dncM14/rut3 deposit eggs that lack germ cells and display discrete morphological defects.
Mutants exhibit enhanced motor terminal aborization, this suggests cAMP levels influence the size of motor axon projections.
rut2 dncM14 flies learn about half as well as wild-type controls.