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General Information
Symbol
Dmel\dnc2
Species
D. melanogaster
Name
FlyBase ID
FBal0002714
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference
Expression Data
Reporter Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Information
Statement
Reference

Immunolocalization of dnc protein to thin sections of adult brain shows that it is largely concentrated in the mushroom bodies. Within mushroom bodies, the γ lobes stain more intensely than the α or β lobes, peduncle staining intensity varies with position and calyx expression is uniform. An intermediate level of staining is seen in most neuropil structures including the inner optic lobe neuropil, protocerebrum, suboesophageal ganglion, antennal lobes, and central complex. A conspicuous lack of staining is found in the photoreceptor cell layer, lamina, antennal nerve, and median bundle. The pattern of dnc2 protein was indistinguishable in heads from the wild type pattern.

 
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 0 )
Disease
Interaction
References
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Mutant males lack 30-minute courtship memory after 1 hour of conditioning in a courtship conditioning assay.

The average amplitudes of synaptic currents recorded in dnc2 mutant aCC and RP2 motorneurons are significantly larger than in wild type and the resting potential of these neurons is depolarized relative to wild type. However, the frequency of synaptic currents is not significantly different. Tetrodotoxin abolishes evoked excitatory currents so that currents elicited from the spontaneous release of vesicles in the presynaptic interneurons can be observed. In the presence of tetrodotoxin, the amplitude distribution and frequency of spontaneous currents is not significantly different between dnc2 mutants and wild type. The ability of aCC/RP2 to fire action potentials (APs) in response to an injection of constant current is decreased in dnc2 mutants compared to wild type; the duration between successive APs and the duration of the APs is increased in the mutant. Input resistance is not significantly different. Voltage-clamp analysis of aCC/RP2 neurons shows a significant reduction in peak current density of voltage-dependent inward Na+ current, a small, insignificant reduction of inward K+ current and no change in inward Ca2+ current in dnc2 mutants compared to wild type. There is an increase in the amount of current required to fire an equal number of APs following treatment with tetrodotoxin, although this is less marked than in wild-type.

Nurse cell dumping is incomplete in egg chambers from homozygous females. 70% of stage 10B and 11 egg chambers are degenerating. Nurse cell dumping is incomplete in egg chambers from 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.

The average miniature EPSC (mEPSC) frequency in dnc2 neurons in culture is significantly higher than in wild-type neurons. The amplitude and kinetic properties of the mEPSCs are similar to wild type.

The frequency of spontaneous release (miniature excitatory junctional currents) at the neuromuscular junction is reduced compared to wild type.

Acetylcholine (ACh) currents are reduced in peak amplitude in cultured dnc2 "giant" neurons. There are events with markedly slower kinetics of rise compared to wild-type neurons. The frequency of spontaneous ACh release in these neurons is similar to wild type. The release frequency is greatly enhanced by repetitive neuronal activity in cultured dnc2 neurons, in contrast to wild type.

The peak dihydropyridine (DHP)-sensitive current in dnc2 larval muscles is significantly increased (126.6 +/- 5.2% of wild-type value) compared to wild type. The peak current is inhibited to 80.5 +/- 3.3% of wild type by 10 μm H-89 (a PKA inhibitor).

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.

Hypomorphic dnc2 mutation appears to disrupt learning more than the amorphic dncM11 mutation.

The voltage-activated transient K+ current (IA) in the larval muscle fibres of both heterozygotes and homozygotes is increased compared to wild-type. The voltage-activated delayed K+ current (IK) in the larval muscle fibres of homozygotes is increased compared to wild-type, but is almost normal in the larval muscle fibres of heterozygotes.

Hemizygous and homozygous flies have a learning index of 0.3 immediately after training, which rapidly falls to approximately 0.1 and remains at this value for at least 6 hours.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
NOT suppressed by
Statement
Reference
Suppressor of
Statement
Reference
Phenotype Manifest In
Suppressed by
Statement
Reference

dnc2/dncM14 has egg chamber phenotype, suppressible | partially by Gprk2[+]/Gprk206936

dnc2 has egg chamber phenotype, suppressible | partially by Gprk2[+]/Gprk206936

Suppressor of
Statement
Reference

dnc2/dnc[+] is a suppressor | partially of nurse cell & nucleus phenotype of Gprk206936

Additional Comments
Genetic Interactions
Statement
Reference

DopEcRc02142 restores 30-minute courtship memory in a courtship conditioning assay in dnc2 males.

Males expressing DopEcRKK111211 under the control of Scer\GAL4αTub84B.Switch.PK in a dnc1 background in the presence of RU486 show 30-minute courtship memory in a courtship conditioning assay.

The egg laying and hatching defects of Gprk206936 homozygous females are partially suppressed by a single copy of dnc2. The defect in tethering of the nurse cell nuclei seen in Gprk206936 homozygous egg chambers is partially suppressed by a single copy of dnc2. dnc2/dnc2 females carrying Gprk206936/+ lay 1.3 eggs/female/hour (wild-type value is 2.9 eggs/female/hour) of which 32.3% hatch. dnc2/dncM14 females carrying Gprk206936/+ lay 1.5 eggs/female/hour of which 31.6% hatch. The egg chamber degeneration of dnc2 homozygotes and dnc2/dncM14 females is partially suppressed by Gprk206936/+.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Comments
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer

Byers.

Comments
Comments

Enzyme activity is 15% of wild-type.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (2)
Reported As
Symbol Synonym
Name Synonyms
Secondary FlyBase IDs
    References (20)