FlyBase Allele Report: Dmel\Mhc[S1]

General Information

Symbol

Dmel\Mhc^S1

Species

D. melanogaster

Name

FlyBase ID

FBal0191167

Feature type

allele

Associated gene

Dmel\Mhc

Associated Insertion(s)

Carried in Construct

Also Known As

Samba¹

Key Links

Genomic Maps

JBrowse

Allele class

Mutagen

ethyl methanesulfonate

Nature of the Allele

Allele class

Mutagen

ethyl methanesulfonate

(Montana and Littleton, 2004)

Progenitor genotype

Cytology

Description

Amino acid replacement: V235E.

(Montana and Littleton, 2004)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

point_mutation

2L:16,770,812..16,770,812 [+]

Nucleotide change:

T16770812A

Amino acid change:

Reported amino acid change:

V235E

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

(Montana and Littleton, 2004)

Variant Molecular Consequences

Associated Sequence Data

DDBJ / EMBL / GenBank

DNA sequence

Protein sequence

UniProtKB/Swiss-Prot

UniProtKB/TrEMBL

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

model of myopathy

CEA

(Montana and Littleton, 2006)

Modifiers Based on Experimental Evidence ( 0 )

Disease

Interaction

References

Comments on Models/Modifiers Based on Experimental Evidence ( 0 )

Disease-implicated variant(s)

Phenotypic Data

Phenotypic Class

abnormal behavior | recessive | heat sensitive

(Montana and Littleton, 2004)

abnormal locomotor behavior | adult stage | dominant

(Pronovost et al., 2013)

abnormal neurophysiology | dominant | heat sensitive

(Montana and Littleton, 2004)

flightless | dominant

(Montana and Littleton, 2004)

lethal | recessive

(Montana and Littleton, 2004)

Phenotype Manifest In

adult external thorax

(Clark et al., 2007)

adult thorax | dorsal

(Pronovost et al., 2013)

dorsal longitudinal indirect flight muscle cell | heat sensitive

(Montana and Littleton, 2004)

indirect flight muscle cell

(Pronovost et al., 2013, Montana and Littleton, 2004)

mesothoracic femur

(Montana and Littleton, 2004)

mesothoracic leg | heat sensitive

(Montana and Littleton, 2004)

muscle attachment site

(Montana and Littleton, 2004)

Detailed Description

Statement

Reference

Heterozygous adults have poor climbing ability. Hypercontraction of the indirect flight muscles can be seen in these animals and 39% have indentations in the dorsal thorax.

(Pronovost et al., 2013)

Mhc^S1/+ flies have indented thorax.

(Clark et al., 2007)

Mhc^S1 adults exhibit dominant temperature-sensitive behavioural defects that include a rapid onset of seizure-like behaviour and temperature-sensitive loss of mesothoracic leg function. This behaviour is readily evident in all flies by 1 min of exposure to 38^oC. Mhc^S1/+ flies are flightless, with thoracic indentations but do not show abnormal behaviour at 38^oC. Mhc^S1 mutants also display defects at permissive temperatures. Homozygous Mhc^S1 mutants are lethal, although some rare Mhc^S1 escapers with femur hypercontraction defects can be found. Correlating with the behavioural defects, abnormal spiking activity in the dorsal longitudinal muscles is observed at restrictive temperatures (38^oC) in Mhc^S1/+ mutants. Mhc^S1/+ mutants exhibit birefringence at muscle attachment sites, with loss of birefringence in the middle of the indirect flight muscles. Type I glutamatergic motor neurons innervation is not altered in Mhc^S1/+ mutant third instar larvae. However, ectopic type II synapse innervation is more frequent in Mhc^S1/+ mutants, increasing from 4.1% to 15.9%. Mutant Mhc^S1/+ muscle fibers exhibit a statistically significant decrease in miniature excitatory junction potential amplitude, excitatory junction potential amplitude, miniature frequency and resting potential compared to wild-type. However, the observed spontaneous muscle movement does not resemble action potential-induced contraction events. Instead, a slow, cyclic activity that does not use the full contractile potential of the muscle cell is continuously observed in Mhc^S1 mutants. Spontaneous contractions are still observed in Ca²⁺-free saline, also regardless of neuronal activity.

(Montana and Littleton, 2004)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Suppressed by

Statement

Reference

Mhc^S1 has abnormal locomotor behavior | dominant | adult stage phenotype, suppressible by rhea^Ubi.PB

(Pronovost et al., 2013)

Mhc^S1 has abnormal locomotor behavior | dominant | adult stage phenotype, suppressible by stck^wt.Tag:FLAG

(Pronovost et al., 2013)

Mhc^S1 has lethal phenotype, suppressible by Tm2^D53

(Montana and Littleton, 2004)

Mhc^S1 has lethal phenotype, suppressible by Swg^X118/Swg[+]

(Montana and Littleton, 2004)

Mhc^S1 has abnormal neurophysiology | heat sensitive phenotype, suppressible by para^ts1

(Montana and Littleton, 2004)

NOT suppressed by

Statement

Reference

Mhc^S1 has abnormal locomotor behavior | dominant | adult stage phenotype, non-suppressible by by^GFP

(Pronovost et al., 2013)

Mhc^S1 has abnormal locomotor behavior | dominant | adult stage phenotype, non-suppressible by mys^{Ubi-p63E.Venus}

(Pronovost et al., 2013)

Mhc^S1 has abnormal locomotor behavior | dominant | adult stage phenotype, non-suppressible by Scer\GAL4^how-24B/Zyx^UAS.EGFP

(Pronovost et al., 2013)

Other

Statement

Reference

Brkd^J29, Mhc^S1 has lethal phenotype

(Montana and Littleton, 2004)

Mhc^S1, up¹⁰¹ has lethal phenotype

(Montana and Littleton, 2004)

Mhc^S1, wupA^hdp-2 has lethal phenotype

(Montana and Littleton, 2004)

Brkd[+]/Brkd^J29, Mhc^S1 has lethal phenotype

(Montana and Littleton, 2004)

Phenotype Manifest In

Suppressed by

Statement

Reference

Mhc^S1 has adult thorax | dorsal phenotype, suppressible by stck^wt.Tag:FLAG

(Pronovost et al., 2013)

Mhc^S1 has indirect flight muscle cell | heat sensitive phenotype, suppressible by para^ts1

(Montana and Littleton, 2004)

Mhc^S1 has indirect flight muscle cell phenotype, suppressible by Tm2^D53

(Montana and Littleton, 2004)

NOT suppressed by

Statement

Reference

Mhc^S1 has indirect flight muscle cell phenotype, non-suppressible by stck^wt.Tag:FLAG

(Pronovost et al., 2013)

Mhc^S1 has indirect flight muscle cell phenotype, non-suppressible by rhea^Ubi.PB

(Pronovost et al., 2013)

Mhc^S1 has adult thorax | dorsal phenotype, non-suppressible by rhea^Ubi.PB

(Pronovost et al., 2013)

Mhc^S1 has adult external thorax phenotype, non-suppressible by Df(3R)Mlp84B^P8/+

(Clark et al., 2007)

Other

Statement

Reference

Mhc^S1, wupA^hdp-2 has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Mhc^S1, Swg^X118/Swg[+] has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Mhc^S1, up[+]/up¹⁰¹ has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Mhc^S1, wupA[+]/wupA^hdp-2 has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Mhc^S1, Swg^X118 has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Mhc^S1, up¹⁰¹ has mesothoracic femur phenotype

(Montana and Littleton, 2004)

Additional Comments

Genetic Interactions

Statement

Reference

stck^{wt.T:Zzzz\FLAG} partially but significantly rescues the poor climbing ability of Mhc^S1 heterozygous adults. Hypercontraction of the indirect flight muscles is not rescued in these animals. Only 2% of the rescued animals have indentations in the dorsal thorax.

The poor climbing ability of Mhc^S1 heterozygous adults is also modestly suppressed if the flies are also carrying rhea^Ubi.PB but neither the hypercontraction of the indirect flight muscles nor the indentations in the dorsal thorax are rescued.

The climbing deficit of Mhc^S1 heterozygotes is not suppressed by combination with either by^T:Avic\GFP or mys^{Ubi-p63E.T:Avic\GFP-YFP.Venus} or by expression of Zyx^{Scer\UAS.T:Avic\GFP-EGFP} under the control of Scer\GAL4^how-24B.

(Pronovost et al., 2013)

Mhc^S1/+; Df(3R)Mlp84B^P8/+ animals are viable and phenotypically indistinguishable from Mhc^S1/+ flies. Similarly to Mhc^S1/+ flies, they have an indented thorax.

(Clark et al., 2007)

Double heterozygotes of Mhc^S1 and Swg^X118 are semi-lethal with escapers having hypercontracted femurs. Hemizygous flies for up¹⁰¹ and heterozygous for Mhc^S1 are synthetic lethal, whereas double heterozygous females have femur hypercontraction defects. Hemizygous flies for wupA^hdp-2 and heterozygous for Mhc^S1 are synthetic lethal, whereas double heterozygous females have femur hypercontraction defects. Double heterozygotes of Mhc^S1 and Brkd^J29 are synthetic lethal. Mhc^S1/+ structural defects are partially suppressed in Tm2^D53 mutants, as the indirect flight muscles of double mutants display less degradation despite the presence of indented thoraces compared to similarly aged Mhc^S1/+ flies. Tm2^D53 suppresses the recessive lethality of Mhc^S1, increasing homozygote viability from 2.38% to 80.92%. Suppression of Mhc^S1 seizure activity is observed in para^ts1; Mhc^S1/+ double mutant males at 38^oC.

(Montana and Littleton, 2004)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Comments

Images (0)

Mutant

Wild-type

Stocks (0)

Notes on Origin

Discoverer

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (3)

Reported As

Symbol Synonym

Mhc^S1

(Guss et al., 2023, Montana and Littleton, 2006)

Mhc^Samba1

(Pronovost et al., 2013)

Samba¹

(Pronovost et al., 2013, Montana and Littleton, 2004)

Name Synonyms

Samba1

(Clark et al., 2007)

Secondary FlyBase IDs

References (5)

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