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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
Additional Notes
Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype
Nature of the lesion

Coding region sequence indicates identical 2bp deletion to eas2, suggesting that the two isolates may actually represent the same mutation.

Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 1 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

There is a drastic increase in DLM firing frequency in eas1 mutants following electroconvulsive seizures (ECS). The temporal characteristics of the ECS-induced wing buzzing shows a gross discrepancy with the DLM firing pattern. Unlike in wild-type, the wing beat frequency in these mutants does not appear to be temporally coupled with the DLM firing episode. Instead, an abrupt termination of wing beats occurs during DLM firing, followed by quiescence prior to a second bout of wing beats when DLM firing is terminated.

Injection of 25mM valproate saline solution greatly increases the seizure threshold of eas1 mutants (i.e. suppresses the seizure phenotype), although this is still below wild-type levels.

Rapid acute exposure to 100% CO[[2]], N[[2]] or He causes seizure-like activity in eas1 mutants. Seizure-like activity is characterized by violent spinning of the flies accompanied by rapid uncoordinated movement of the wings, legs and abdomen. The initial bout of seizure-like activity, which usually occurs within 10 seconds of the onset of gas exposure, is followed by a period of paralysis in which the flies lay motionless. The paralysis is interrupted by bouts of delayed seizure-like activity that begins 30 to 60 seconds following the initial seizure-like activity. The delayed seizure-like activity is much more variable than the initial activity, as it often consists of multiple bouts of activity interspersed with periods of paralysis.

Repeat exposure to CO[[2]] reduced the severity of seizure-like activity. eas1 flies that are exposed to a second round of CO[[2]] exposure as soon as they recover from an initial acute exposure to CO[[2]], a process that takes approximately 3 minutes, are immobilized by the exposure but the amount of seizure-like activity is reduced. For example, following the first exposure, 83% of bss1 flies display delayed seizure-like activity while following the second exposure only 58% of the flies display this activity.

Exposure of eas1 flies to a 50/50 mix of CO[[2]] and O[[2]] results in initial and delayed seizure-like activity, indicating that hypercapnia is sufficient to trigger seizure-like activity in these flies as they have more than twice the level of atmospheric oxygen during exposure to the 50/50 mix. These flies are also susceptible to CO[[2]] induced anesthetization.

Mixtures of 95% N[[2]] and 5% O[[2]] or 95% He and 5% O[[2]] do not trigger seizure-like activity in eas1 flies. In fact, at 98% N[[2]] or He and 2% O[[2]], these flies do not exhibit seizure-like activity, although they do become sluggish. When the amount of O[[2]] is reduced even further to 1% or less, the flies begin to become anesthetized and in many cases exhibit seizure-like activity.

Exposure of eas1 to pure CO[[2]], He or O[[2]] for 2-5 minutes results in initial seizure-like activity but fails to generate the delayed seizure-like activity seen following acute exposure. After the initial seizure-like activity, the flies remain motionless throughout the duration of the 2- to 5-minute gas exposure. Once the gas exposure ends, the flies gradually recover normal function without displaying any delayed seizure-like activity.

The giant fiber(GF)-dorsal longitudinal indirect flight muscle (DLM) neuronal circuit is more sensitive to seizure induction in mutants than in wild-type flies; seizures can be induced with high-frequency brain stimulation of shorter or less intensity in the mutant animals. The mutant animals show predominantly type II seizures, although type I seizures are also commonly observed.

The seizure threshold following short wavetrains of high-frequency electrical stimuli (0.5ms pulses at 200Hz for 300ms) is reduced in mutant flies (3.4 +/- 0.5 V) compared to controls.

The threshold for activation of the giant fiber in mutant animals following single stimulus pulses (0.2ms duration, 0.5Hz) is not significantly different from that of wild type.

Bang sensitive paralytic mutant.

Brief paralysis following exposure to mechanical shock; this phenotype suppressed by mlenap-ts1 mutation at its permissive temperature; release of neurotransmitter at larval neuromuscular junction is apparently normal.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
NOT Enhanced by

eas1 has behavior defective phenotype, non-enhanceable by Df(2L)TW1/+

Suppressed by

eas1 has paralytic | drug conditional phenotype, suppressible | partially by Mdr65MI00104

NOT suppressed by

eas1 has behavior defective phenotype, non-suppressible by Df(2L)TW1/+

Phenotype Manifest In
Additional Comments
Genetic Interactions

A Mdr65MI00104 background partially suppresses the seizure phenotype in eas1 flies.

Df(2L)TW1/+ does not significantly alter the seizure phenotype of eas1 hemizygotes.

shakB2 partially suppresses the reduced seizure threshold of eas1 flies following high-frequency electrical stimuli.

Xenogenetic Interactions
Complementation and Rescue Data
Images (0)
Stocks (0)
Notes on Origin

No apparent defect in the larval neuromuscular junction preparation. Behavioral phenotype suppressed by mlenap-ts1, even at permissive temperatures.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
References (10)