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General Information
Symbol
Dmel\comt6
Species
D. melanogaster
Name
FlyBase ID
FBal0001760
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
comttp7, comatosetp7
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
point mutation
Nucleotide change:
C13260669T
Amino acid change:
P398S | comt-PA; P398S | comt-PB
Reported amino acid change:
P398S
Comment:
Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference
Amino acid replacement: P398S. The mutation is within the D1 domain.
Amino acid replacement: P398S.
Expression Data
Reporter Expression
Additional Information
Statement
Reference
 
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 1 )
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
comt6/comt6 mutants exhibit severely reduced lifespans when reared at 29[o]C, and a milder reduced lifespan phenotype when reared at 22[o]C; display neurodegeneration, as assessed by presence of vacuoles in the neuropil, after 48-hr exposure to 29[o]C; display a moderate climbing defect when reared at 22[o]C, and loss of climbing ability after shifting to 29[o]C; decreased survival during prolonged starvation during adulthood at 22[o]C, as compared with wild type flies.
Both the on- and off-transients of the electroretinogram are lost in comt6 flies incubated at 38[o]C for 1 minute. Upon transfer to the permissive temperature of 21[o]C, the transients do not return before 40 minutes.
Synapse strength (neurotransmitter release per action potential) is increased compared to wild type at muscle 6/7 neuromuscular junctions in mutant larvae.
After a 4 minute exposure to 350C, comt6 mutants have convulsions that last over one hour at room temperature. At 200C, comt6 mutants show wild-type levels of DLM firing activity. However, after 4 minutes of exposure to non-permissive temperatures, these mutants show a greater increase in strong, spontaneous activity for at least one hour.
Rare escapers of the lethality show the same uncoordination phenotype as those of comtclp and comt3-13-3. Hemizygous male larvae take much longer than wild type to roll from lying on their dorsal surface to their ventral surface.
Mutant flies are paralysed at 35oC.
Electroretinograms taken from the retina at 38oC reveal losses of on/off transients in mutants.
comt6 shows complete lethality if it is shifted to the restrictive temperature (33[o]C) at 72 hours after egg laying. comt6 animals raised at 30[o[]C show normal development until pupariation, but all adults are incapable of eclosion and how seizure-like behaviour.
Homozygous flies paralyse within 1 minute at 38oC after a burst of activity and recover at 20oC in 30 minutes. comt6 parats2 double homozygotes paralyse within 15 seconds at 38oC (a time course similar to parats2 single homozygotes). A burst of activity preceeding paralysis (as seen in comt6 single homozygotes) does not occur in the double mutants. After shifting to 20oC, the double mutant flies appear to recover immediately and after a period of 10 seconds into recovery, almost all the flies are upright. During this period, increased activity is observed, but by 30 seconds, more than half the upright flies paralyse again, and this paralysis is complete by 1 minute. Recovery after this second round of paralysis proceeds in a manner similar to that of comt6 single mutant flies, albeit somewhat faster. The dorsal longitudinal muscles of comt6 flies show hardly any spontaneous firing at 20oC, but show a characteristic spontaneous burst of activity at 36oC. This firing continues for up to 2 minutes at 36oC, followed by a progressive reduction in spike amplitude and eventual quiescence. No further activity is detected on cooling to 32oC. The burst of spontaneous activity seen at 36oC in the dorsal longitudinal muscles of comt6 single mutant flies is completely suppressed in comt6 parats2 double homozygotes. On cooling to 32oC, a robust comt6-like burst of spontaneous firing is seen in the double mutant flies (this is not seen in comt6 single mutant flies).
The action potentials of the dorsal longitudinal flight muscle (DLM) are indistinguishable from wild-type at the permissive temperature. At the restrictive temperature an activity-dependent reduction in the DLM action potential and postsynaptic potential is seen. The number of docked vesicles per active zone is higher than wild-type in the neuromuscular synapses of the coxal muscles (at the restrictive temperature).
In ERG assay, mutants lose the on/off transients at 38oC, though over a slower time course than for Syx1A3-69. Recovery of transients at 20oC is slower than for Syx1A3-69. ERG phenotypes correlate with paralytic phenotypes: time course of paralysis and recovery for Syx1A mutants is more rapid than for comt mutants.
Sub-anaesthetic concentration of carbon dioxide fails to suppress the paralytic phenotype.
External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement
Reference
comt6 has paralytic | heat sensitive phenotype, enhanceable by E(comt[6])21E[+]/E(comt6)21E21E
comt6 has paralytic | heat sensitive phenotype, enhanceable by E(comt6)E32E32/E(comt[6])E32[+]
NOT Enhanced by
Statement
Reference
comt6 has paralytic | heat sensitive phenotype, non-enhanceable by awdCM47
comt6 has paralytic | heat sensitive phenotype, non-enhanceable by awdMSF15
comt6 has paralytic | heat sensitive phenotype, non-enhanceable by awdMSM95
comt6 has paralytic | heat sensitive phenotype, non-enhanceable by stnB6/stnA6
Suppressed by
Statement
Reference
comt6 has paralytic | heat sensitive phenotype, suppressible by su(comt6)S14S14/su(comt6)S14S14
comt6 has paralytic | heat sensitive phenotype, suppressible by Atal[+]/AtalS13
comt6 has neurophysiology defective | adult stage | heat sensitive phenotype, suppressible by Atal[+]/AtalS13
comt6 has paralytic | heat sensitive phenotype, suppressible by Scer\GAL4elav-C155/Nsf2UAS.cGa
Other
Phenotype Manifest In
NOT Enhanced by
Statement
Reference
Suppressed by
Other
Additional Comments
Genetic Interactions
Statement
Reference
E(comt6)21E21E/+ enhances the temperature sensitive paralytic phenotype of comt6. The time taken for flies to paralyse at 34.5[o]C is significantly decreased and the time taken for complete recovery after exposure to 38[o]C for 1 minute is prolonged. comt6 E(comt6)21E21E/+ flies paralyse within 3 minutes at 32[o]C (comt6 single mutants do not paralyse under these conditions). E(comt6)E32E32/+ enhances the temperature sensitive paralytic phenotype of comt6. The time taken for flies to paralyse at 34.5[o]C is significantly decreased and the time taken for complete recovery after exposure to 38[o]C for 1 minute is prolonged. comt6 E(comt6)E32E32/+ flies paralyse within 3 minutes at 32[o]C (comt6 single mutants do not paralyse under these conditions). su(comt6)S14S14 is a recessive suppressor of the temperature sensitive paralytic phenotype of comt6. The time taken for complete recovery after exposure to 38[o]C for 1 minute is shortened. AtalS13/+ suppresses the temperature sensitive paralytic phenotype of comt6. The time taken for complete recovery after exposure to 38[o]C for 1 minute is shortened. AtalS13/+ reduces the time taken for on- and off-transients of the electroretinogram to return from 40 minutes to 10 minutes when comt6 flies are shifted to 21[o]C after being incubated at 38[o]C for 1 minute.
comt6 Ca-P60AKum170 double mutants exhibit increased synapse growth and transmitter release. Scer\GAL4OK6-driven motor neuron-limited expression of NFATEP19579 or NFATEP1508 completely abolishes increased synapse growth and transmitter release observed in comt6 Ca-P60AKum170 double mutants.
comt6 Ca-P60AKum170 double mutant flies show increased locomotor activity compared to wild-type controls. The average number of synaptic boutons at the muscle 6/7 neuromuscular junction is increased in comt6 Ca-P60AKum170 larvae compared to controls. In addition, synapse strength (neurotransmitter release per action potential) is increased compared to wild type, as is seen in each single mutant. Expression of ShEKO.Scer\UAS.T:Avic\GFP-GL under the control of Scer\GAL4futsch-C380 suppresses the increased synaptic growth and transmitter release observed at the neuromuscular junction in comt6 Ca-P60AKum170 larvae. Expression of either Ras85DN17.Scer\UAS or phlDN.Scer\UAS.cUa in motor neurons under the control of Scer\GAL4unspecified suppresses the increased synaptic growth and transmitter release observed at the neuromuscular junction in comt6 Ca-P60AKum170 larvae. Expression of either kayFbz.Scer\UAS or CrebB-17AScer\UAS.b.cYa in motor neurons under the control of Scer\GAL4unspecified suppresses the increased synaptic growth and transmitter release observed at the neuromuscular junction in comt6 Ca-P60AKum170 larvae.
comt6; Ca-P60AKum170 double mutants show an increase in strong, spontaneous DLM activity in response to restrictive temperatures that is similar to comt6 single mutants. comt6 parats1; Ca-P60AKum170 triple mutants do not show spontaneous DLM firing activity at 330C like comt6 and Ca-P60AKum170 single mutants, but these triple mutants do show an increase of activity when shifted to 400C, the restrictive temperature for parats1 mutants.
Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Rescued by
Partially rescued by
Comments
Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
Siddiqi.
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (8)
References (19)