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General Information
Symbol
Dmel\sei1
Species
D. melanogaster
Name
FlyBase ID
FBal0015409
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
seits1
Key Links
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Nucleotide change:

A24050274T

Amino acid change:

K282term | sei-PA; K282term | sei-PB; K282term | sei-PC

Reported amino acid change:

K282term

Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference

The premature stop codon is before the first membrane-spanning segment.

The premature stop codon results in a protein that lacks the hydrophobic core that forms the transmembrane channel.

Amino acid replacement: K282term.

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 ( 1 )
Disease
Interaction
References
model of  epilepsy
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
Disease-implicated variant(s)
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Mutant flies show rapid paralysis in response to acute heat stress.

sei1 mutant flies are paralysed at elevated temperatures.

Intracellular recordings from mutant dorsal longitudinal muscles show bursts of spontaneous activity at 37[o]C.

sei1/sei2 mutants display abundant small boutons, termed 'satellites', budding from the larger primary boutons along the branch axis. Such aberrant outgrowth is found at both type Ib and Is neuromuscular junctions in different muscles, e.g. 6/7 and 4. Upon closer examination, two distinct types of satellites are observed, one without a clear constriction between satellites and primary boutons, resembling yeast budding (type B satellites) and the other with a short but clear constriction or 'neck' (type M satellites). Type M satellites are more abundant than type B satellites in these mutants. There is also an overall increase in synaptic bouton number and terminal branching in these mutants.

sei1 mutants display significantly enhanced branching patterns along with a robust increase in mature bouton numbers, indicating that sei mutants do not fully prevent type M satellites from entering the successive growth steps.

Exposure to high temperatures (29[o]C) for 2 hours during development fails to induce significant morphological changes in synaptic growth in sei1 mutants. However, numbers of both B- and M-type satellites are drastically reduced after 5 hours of high temperature. Wild-type synapses do not exhibit this behaviour.

Chronic high temperature treated (>5 hours) sei1 mutants exhibit an unusual population of terminal branches consisting of thin strings of type M (and occasionally type B) satellites that are absent in controls. These unusual terminal branches contribute to the increased branching complexity in sei1 mutants. These mutants also exhibit a decrease in primary bouton number.

sei1 mutants display a 60% increase in bouton number at 31[o]C compared with 25[o]C.

sei1 flies do not show a significantly shortened lifespan. At day 37, these flies exhibit sporadic vacuoles throughout the central nervous system. Exposing these mutants to 40oC for 3 minutes results in seizures that last for up to a minute followed by paralysis. The severity of the phenotype progresses with age and daily exposure to the restrictive temperature.

sei1 mutants show behavioral convulsions after brief exposure to elevated temperature.

The courtship song parameters interpulse interval, cycles per pulse, interpulse frequency and amplitude of sound are normal in homozygous males at 25oC.

Substantial enhancement of spontaneous neural activity.

Heat induced expression of seihs.PW in adults is sufficient to restore normal locomotor function.

Homozygous larvae raised at the restrictive temperature (37oC for 6 hours/day from late embryogenesis through to third larval instar) show an increased frequency of ectopic neuromuscular synapses. Embryos raised at 18oC or 34oC show an increased frequency of immature filopodial contacts on muscle fibres 6 and 7 ("collateral sprouts") compared to wild-type embryos raised at the same temperature.

The delivery of an electrical buzz (50-400 msec) to the brain has no significant effect on sei1 mutant flies.

Spontaneous dorsal longitudinal muscle responses increase in frequency as the temperature is increased.

At temperatures >40oC, sei2 causes spontaneous activity in recordings from dorsal longitudinal flight muscles, to appear coincidentally with the heat-induced paralysis.

sei2 is semidominant in this respect and behavior of hyperploid adults exhibits dose dependence: sei2/sei2/+ flies become paralyzed, at 40oC, slightly less rapidly than homozygous mutants; sei2/+/+ paralyzed more slowly than sei2/+ but faster than wild-type.

Recordings of action potentials in the adult giant-fiber pathway reveal no decrement in sei2 at 40oC.

temperature-sensitive

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement
Reference

sei1 has abnormal neuroanatomy phenotype, enhanceable by sei1

Suppressed by
Statement
Reference

sei1 has paralytic | adult stage phenotype, suppressible | partially by Csas[+]/CsasMB04236

sei1 has abnormal neuroanatomy | temperature conditional phenotype, suppressible by Syt4BA1

Enhancer of
Statement
Reference

sei1 is an enhancer of abnormal neuroanatomy phenotype of sei1

NOT Enhancer of
Statement
Reference

sei1/sei[+] is a non-enhancer of short lived | dominant phenotype of AtpαDTS1

Suppressor of
Statement
Reference

sei1/sei[+] is a suppressor | partially of paralytic | adult stage phenotype of CsasMB04236

sei1 is a suppressor of abnormal neuroanatomy phenotype of slo1

Phenotype Manifest In
Enhanced by
Statement
Reference

sei1 has NMJ bouton | increased number phenotype, enhanceable by sei1

sei1 has neuromuscular junction phenotype, enhanceable by sei1

sei1 has phenotype, enhanceable by e(sei)1

Suppressed by
Statement
Reference

sei1 has neuromuscular junction | temperature conditional phenotype, suppressible by Syt4BA1

sei1 has NMJ bouton | temperature conditional phenotype, suppressible by Syt4BA1

Enhancer of
Statement
Reference

sei1 is an enhancer of NMJ bouton | increased number phenotype of sei1

sei1 is an enhancer of neuromuscular junction phenotype of sei1

Suppressor of
Statement
Reference

sei1 is a suppressor of NMJ bouton | increased number phenotype of slo1

sei1 is a suppressor of neuromuscular junction phenotype of slo1

Additional Comments
Genetic Interactions
Statement
Reference

One copy of sei1 partially suppresses the paralytic phenotype seen in CsasMB04236 mutant flies in response to elevated temperatures.

One copy of CsasMB04236 partially suppresses the paralytic phenotype seen in sei1 mutant flies in response to elevated temperatures.

daob4 sei1/daog1 sei1 double mutants show the same time to paralysis on shifting to the restrictive temperature as either single mutant.

When compared with single mutants, the combined mutational effects of sei1/slo1 are not simply additive, with a further enhancement of some slo, but not sei phenotypes. Satellite abundance is less extreme in sei1/slo1 double mutants compared to sei1 mutants. There is a slight, but not significant, reduction in the numbers of both types B and M satellites. In contrast, the numbers of type M (but not type B) satellites and mature boutons are significantly greater in double mutants compared to slo single mutants.

sei1 ; Syt4BA1 double mutants exhibit no significant change in bouton number between 25[o]c and 31[o]C.

sei1/+; AtpαDTS1/+ double mutants have a similar lifespan to AtpαDTS1/+ single mutants.

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

Reduced level of saxitoxin binding in head membrane extracts and a decreased sodium current density in cultured embryonic neurons.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (23)