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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Key Links
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
Additional Notes
Nucleotide change:


Reported nucleotide change:


Amino acid change:

F401I | Sh-PB; F389I | Sh-PC; F356I | Sh-PD; F401I | Sh-PE; F389I | Sh-PI; F389I | Sh-PJ; F389I | Sh-PL; F401I | Sh-PQ; M1I | Sh-PS; F401I | Sh-PT

Reported amino acid change:


Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype

Polytene chromosomes normal.

Nature of the lesion

Point mutation within the S5 region.

Missense mutation in the region connecting the proposed transmembrane segment S5 of the Sh K+ channel proteins.

Mutation in the V region of the Sh locus.

Nucleotide substitution: T to A. Amino acid replacement: F401I. In the leucine zipper region.

Nucleotide substitution of T to A in exon 14, which replaces a Phe with an Ile.

Point mutation.

sequenced by Lichtinghagen et al., 1990 phe371 to ile; relative to the deduced H37 protein (Kamb, Tseng-Crank and Tanouye, 1988).

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 ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

Sh5 homozygous adults exhibit locomotion defects, including increased movement time spent in the centre of a circular space (instead of movement mostly along the edges) and significantly increased velocities of head and hind-leg movements under ether anesthesia (the leg movements are continuous and do not stop immediately after severance from the body), as compared to controls.

Sh5 mutant flies display largely normal flight parameters, with wing beat frequency, DLM firing rate, and inter-spike-interval CV not differing significantly from wild-type.

Mutant flies exhibit a decrease in the daily sleep amount. This is mainly due to a decrease in the duration of sleep episodes rather than in their number. This phenotype is very sensitive to background modifiers.

The seizure threshold following short wavetrains of high-frequency electrical stimuli (0.5ms pulses at 200Hz for 300ms) is slightly increased in mutant flies (51.3 +/- 6.1 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.

The giant fiber following frequency (the maximum stimulation frequency that the giant fiber pathway can reliably follow) is reduced compared to wild type in mutant animals.

When exposed to 10mM paraquat for 48hr, mutants show 30% survival (wild type shows 97% survival).

Sh5 flies treated with sodium valproate (NaVP) do not show a reduction in body weight, in contrast to wild-type flies. Sh5 heterozygotes also show an increase in resistance to lethality caused by NaVP compared to wild type. Sh5 flies treated with phenytoin sodium show an increase in body weight, as is seen in wild-type flies.

Habituation of the giant fiber escape pathway occurs more rapidly in Sh5 flies than in wild-type. The long-latency response is delayed slightly. The short-latency response of the tergotrochanteral muscle is delayed. Habituation in Hk1 Sh5 double mutants is markedly retarded, as in Hk1 single mutants, rather than more rapid as in Sh5 single mutants.

Hemizygous males exhibit an anesthesia-induced leg shaking phenotype, females appear wild type.

Homozygous adults are more sensitive to paraquat than control flies. Homozygous adults have a reduced lifespan compared to wild-type flies.

The life expectancy of Sh5 hemizygous males is shortened, as compared to controls.

Application of serotonin failed to alter modulation of the potassium channel in a semi-intact preparation of the retina.

Homozygotes show increased sensitivity to chloroform and trichloroethylene, but not to halothane in an inebriometer assay (an assay of geotactic and postural behaviour) compared to wild-type flies.

Mutant flies show a shortened life span due to a normal, but accelerated, course of aging at 18oC and 25oC.

Two-electrode voltage clamp technique is used to measure end-plate currents in larval neuromuscular junctions. Currents are four fold larger than wild type, lack post-tetanic potentiation (PTP) but could undergo facilitation. PTPs could be restored by addition of Cd2+.

Vibration of appendages in spaced bursts. Double mutant combinations with tta1 show slight suppression of the Sh phenotype. Sh phenotype is enhanced by the presence of one extra copy of tta.

eag4PM Sh5 double mutant flies do not show spontaneous activity of the dorsal longitudinal and dorsoventral indirect flight muscles when at rest.

Heterozygotes show ether induced leg shaking. Hemizygous males show a reduced preference for sucrose compared to wild-type in feeding preference tests, probably due to a shift in the threshold of detection. Flies show an enhanced attraction to 100mM NaCl and an increased tolerance to 0.5M NaCl and 0.2M KCl compared to wild-type. The increased tolerance to 0.5M NaCl and 0.2M KCl is due to an increase in the threshold of repulsion. The firing patterns of the labellar chemosensory neurons in response to sucrose, NaCl and KCl are normal.

The depolarisation of the Sh5 current steady-state inactivation curve is enhanced compared to wild-type in cells from the thoracic ganglia of very late stage pupae.

Flies manifest chronic vibration of their appendages as well as abnormal action potentials.

The I-V relation and kinetics of IA are altered in homozygous third larval instar muscles, probably indicating altered properties of the IA channel. IA is much lower than predicted by simple gene-dosage dependence in Sh5/Sh14 or Sh5/Sh7 flies.

The voltage required to activate and inactivate the A1 channel is increased by approximately 20mV, and the steepness of the voltage dependence of steady-state inactivation is decreased in cultured embryonic Sh5 myotubes.

A-type current is altered but not abolished.

Sh5 males show no conditioning of courtship behaviour. Sh5 mlenap-ts1 double mutant males or Sh5 males treated with tetrodotoxin are essentially normal in their acquisition of conditioned courtship behaviour, but are defective in retention of the conditioned response.

Ether-dependent leg shaking and wing scissoring. Chloroform, ethyl acetate and carbon dioxide etherization does not elicit shaking behavior, though nitrogen and triethylkamine etherization does. Unetherized, older flies show uncoordinated walking behavior, and stand quivering on the bottom of the culture bottle.

Hemizygous males show a 18% reduction in lifespan. Heterozygous females show only a slight reduction in lifespan.

abnormal leg shaking under ether anesthesia; abnormal A-type potassium currents in larval muscle and/or pupal flight muscle; abnormal action potentials in the adult cervical giant fiber; abnormal synaptic transmission at the larval neuromuscular junction and multiple firing of larval motoneurons.

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

Sh5 has hyperactive phenotype, enhanceable by qvr1

Sh5 has chemical sensitive phenotype, enhanceable by qvr1

NOT Enhanced by

Sh5 has visible phenotype, non-enhanceable by qvr1

Enhancer of

Sh5 is an enhancer of chemical sensitive phenotype of qvr1

Sh5 is an enhancer of hyperactive phenotype of qvr1

NOT Enhancer of

Sh5 is a non-enhancer of visible phenotype of qvr1

Phenotype Manifest In
Suppressed by

Sh5 has phenotype, suppressible by paralk5

NOT Enhancer of

Sh5 is a non-enhancer of wing phenotype of Hk1

Additional Comments
Genetic Interactions

No wings down phenotype was observed for qvr1 in combination with Sh21, Sh5 or Sh16 though leg shaking is more vigorous in these double mutants than in either of the Sh of qvr single mutants alone.

eag1 Sh5 and eag24 Sh5 double mutants exhibit vigorous leg-shaking behaviour under ether anaesthesia. Many exhibit a wings down phenotype. High frequency, spontaneous EJPs of a greater amplitude are seen at larval neuromuscular junctions and spontaneous discharges of EJPs or action potentials can be recorded in adult flight muscles.

The leg shaking phenotype is suppressed by paralk5.

Xenogenetic Interactions
Complementation and Rescue Data
Images (0)
Stocks (2)
Notes on Origin



The reduced lifespan focus appears to map to the anterior ventral region of the blastoderm, possibly to the anterior part of the thoracic ganglion. This focus is domineering; mosaic flies containing one mutant and one wild-type focus have a reduced lifespan.

Phenotype suppressed by mlenap-ts1, even at permissive temperatures. Shaking and suppressed phenotypes are evident in severed legs as well as in the whole organism.

Mutation site is identical to that of Sh7 and Sh14.

Allelic series of Sh defects: Sh7 > Sh14 > Sh16 > Sh5 > Sh9.

Sh14 and Sh5 are not separable by recombination so are suggested to be closely linked point mutations.

Kinetic analysis of single Sh5 channels shows that the transition rates into and out of the open state are not significantly affected by the Sh5 mutation, but the latency until the channel opens following a voltage step is increased at low voltages.

The severity of the sucrose preference defect shows the following order: Sh8 > Sh5 = Sh7 > Sh25 > T(1;Y)V7 > Sh14. The degree of tolerance to 0.5M NaCl shows the order: Sh8 > Sh7 = Sh5 > T(1;Y)V7 = Sh25 > Sh14. The degree of tolerance to 0.2M KCl shows the order: Sh8 = Sh7 = Sh14 > T(1;Y)V7 > Sh5.

Mutation shifts the voltage dependence of the mutated channel.

Electrophysiological analysis reveals repetitive firings of burst-shaped action potentials.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (1)
References (50)