FlyBase Allele Report: Dmel\gbb[2]

General Information

Symbol

Dmel\gbb²

Species

D. melanogaster

Name

FlyBase ID

FBal0098239

Feature type

allele

Associated gene

Dmel\gbb

Associated Insertion(s)

Carried in Construct

Key Links

Genomic Maps

JBrowse

Allele class

amorphic allele - genetic evidence

Mutagen

Nature of the Allele

Allele class

amorphic allele - genetic evidence

(Ray and Wharton, 2001, Wharton et al., 1999)

Mutagen

Progenitor genotype

Cytology

Description

Amino acid replacement: W368term.

(Wharton et al., 1999)

Coordinates as in FBrf0054935.

(Wharton et al., 1999)

Nucleotide substitution: G1509A.

(Wharton et al., 1999)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

point_mutation

2R:23,852,858..23,852,858 [+]

Nucleotide change:

G23852858A

Reported nucleotide change:

G1509A

Amino acid change:

W368term | gbb-PA; W368term | gbb-PB

Reported amino acid change:

W368term

Comment:

TGG to TGA

(Wharton et al., 1999)

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 ( 0 )

Disease

Evidence

References

Modifiers Based on Experimental Evidence ( 1 )

Disease

Interaction

References

ameliorates Huntington's disease

modeled by Hsap\HTT^{Q138.UAS.mRFP1}

(Akbergenova and Littleton, 2017)

Comments on Models/Modifiers Based on Experimental Evidence ( 1 )

gbb² used in trans to gbb¹ ameliorates the phenotype of Hsap\HTT^{Q138.UAS.mRFP1}.

(Akbergenova and Littleton, 2017)

Disease-implicated variant(s)

Phenotypic Data

Phenotypic Class

Phenotype Manifest In

bouton (with gbb¹), with gbb^UAS.cKa

(McCabe et al., 2003)

embryonic/larval anterior midgut | embryonic stage

(Wharton et al., 1999)

embryonic/larval cuticle

(Wharton et al., 1999)

embryonic/larval posterior spiracle

(Wharton et al., 1999)

embryonic midgut constriction 1

(Wharton et al., 1999)

fat body

(Wharton et al., 1999)

imaginal disc

(Wharton et al., 1999)

larva

(Wharton et al., 1999)

NMJ bouton (with gbb¹)

(James et al., 2014)

posterior crossvein

(Wharton et al., 1999)

stigmatophore

(Wharton et al., 1999)

synapse (with gbb¹), with gbb^UAS.cKa

(McCabe et al., 2003)

synapse & neuromuscular junction (with gbb¹), with gbb^UAS.cKa

(McCabe et al., 2003)

telson

(Wharton et al., 1999)

terminal bouton (with gbb¹)

(Sulkowski et al., 2014)

wing

(Wharton et al., 1999)

wing vein

(Wharton et al., 1999)

wing vein | ectopic

(Wharton et al., 1999)

wing vein L2

(Wharton et al., 1999)

wing vein L4

(Wharton et al., 1999)

wing vein L5

(Wharton et al., 1999)

Detailed Description

Statement

Reference

The amplitude of spontaneous miniature excitatory junction potentials (mEJPs) at the neuromuscular junction is not significantly different from controls in gbb¹/gbb² larvae, while the mEJP frequency is significantly decreased. There is a significant decrease in evoked EJP amplitude and in quantal content in the mutant larvae.

gbb¹/gbb² larvae show defects in synaptic vesicle cycling (as assayed using uptake and unloading of the dye FM1-43), showing modest defects in endocytosis and more marked defects in exocytosis.

(James et al., 2014)

gbb¹/gbb² mutant larvae have a reduced number of NMJ boutons compared to controls.

(Sulkowski et al., 2014)

The evoked synaptic current amplitude recorded in aCC/RP2 neurons is significantly smaller in gbb² homozygotes compared with heterozygous controls.

(Baines, 2004)

Very few gbb¹/gbb² animals survive to the 3rd instar larval stage. Synapse size and bouton density are greatly reduced at neuromuscular junctions in gbb¹/gbb²; P{UAS-gbb.K}9.9 larvae compared to wild-type. There is a severe decrease in the amplitude of evoked excitatory junctional potentials (EJP) in this mutant combination when compared to wild-type. The mutants also show a small increase in mini-EJP amplitude and a reduction in the frequency of spontaneous release when compared to wild-type. Measurements of quantal content of these mutant synapses shows that they release 4-fold less neurotransmitter than wild-type synapses.

(McCabe et al., 2003)

Less than 10% of mutants dies as embryos. Mutant larvae are lethargic and flaccid. Imaginal discs are dramatically reduced. Fat body morphology is abnormal, giving rise to transparent phenotype. Cuticle exhibits defects in the telson region. In severe cases posterior spiracles do not protrude from the larval bosy and the stigmatophores are partially fused and more dorsally situated. In embryogenesis, formation of the anterior midgut constriction starts but fails to reach completion, giving rise to a bulbous anterior midgut. The position of the other constrictions is shifted. In gbb²/gbb⁴, wings are small, and more pointed than wild type. Posterior crossveins are absent. Regions of L4 and L5 are lost. The extent of vein loss depends on the strength of the allelic combination. Some mutant combinations show a slight thickening of distal L2 sometimes with ectopic flanking vein material.

(Wharton et al., 1999)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

NOT Enhanced by

Statement

Reference

gbb²/gbb¹ has abnormal neuroanatomy phenotype, non-enhanceable by Neto[+]/Neto³⁶

(Sulkowski et al., 2014)

Suppressed by

Statement

Reference

gbb² has visible | somatic clone phenotype, suppressible by Dp(2;2)DTD48

(Ray and Wharton, 2001)

Suppressor of

Statement

Reference

gbb²/gbb[+] is a suppressor of abnormal locomotor behavior | third instar larval stage phenotype of Timp^S1

(Shilts and Broadie, 2017)

Phenotype Manifest In

NOT Enhanced by

Statement

Reference

gbb²/gbb¹ has terminal bouton phenotype, non-enhanceable by Neto[+]/Neto³⁶

(Sulkowski et al., 2014)

Suppressed by

Statement

Reference

gbb² has wing vein L5 | distal | somatic clone phenotype, suppressible by Dp(2;2)DTD48/Dp(2;2)DTD48

(Ray and Wharton, 2001)

gbb² has wing vein L5 | somatic clone phenotype, suppressible by Dp(2;2)DTD48/Dp(2;2)DTD48

(Ray and Wharton, 2001)

gbb² has wing | somatic clone phenotype, suppressible by Dp(2;2)DTD48/Dp(2;2)DTD48

(Ray and Wharton, 2001)

NOT suppressed by

Statement

Reference

gbb² has posterior crossvein | somatic clone phenotype, non-suppressible by Dp(2;2)DTD48/Dp(2;2)DTD48

(Ray and Wharton, 2001)

Suppressor of

Statement

Reference

gbb²/gbb[+] is a suppressor | partially of NMJ bouton | increased number | third instar larval stage phenotype of Timp^S1

(Shilts and Broadie, 2017)

Additional Comments

Genetic Interactions

Statement

Reference

The increased number of bouton at neuromuscular junctions along with the peristaltic contraction defects (longer wave duration, variable frequency pattern) observed in Timp^S1 third instar larvae is significantly ameliorated by gbb² heterozygosity.

(Shilts and Broadie, 2017)

The ability of gbb^Scer\UAS.cKa expressed under the control of Scer\GAL4^Toll-6-D42 to rescue the electrophysiological defects seen at the neuromuscular junction in gbb¹/gbb² larvae is impaired but not completely abolished if the larvae are also homozygous for cmpy^Δ8.

(James et al., 2014)

One copy of Neto³⁶ does not enhance the reduction in NMJ bouton number seen in gbb¹/gbb² mutant larvae.

(Sulkowski et al., 2014)

Two copies of Dp(2;2)DTD48 are able to rescue the distal tip of vein L5 in gbb² homozygous clones in the posterior compartment of the wing. The posterior crossvein is not rescued. Anterior gbb² homozygous wing clones show rescue of both wing size and loss of vein L5.

(Ray and Wharton, 2001)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Rescued by

gbb²/gbb¹ is rescued by gbb^UAS.cKa/Scer\GAL4^Toll-6-D42

(James et al., 2014)

Partially rescued by

gbb²/gbb¹ is partially rescued by Scer\GAL4^BG380/gbb^UAS.cKa

(McCabe et al., 2003)

gbb²/gbb¹ is partially rescued by Scer\GAL4^G14/gbb^UAS.cKa

(McCabe et al., 2003)

gbb²/gbb¹ is partially rescued by Scer\GAL4^elav-C155/gbb^UAS.cKa

(McCabe et al., 2003)

gbb²/gbb¹ is partially rescued by gbb^UAS.cKa

(McCabe et al., 2003)

Comments

Expression of gbb^Scer\UAS.cKa under the control of Scer\GAL4^Toll-6-D42 rescues the reduction in spontaneous miniature excitatory junction potential frequency, evoked excitatory junction potential amplitude and quantal content which is seen at the neuromuscular junction in gbb¹/gbb² larvae.

(James et al., 2014)

The presence of P{UAS-gbb.K}9.9 alone (in the absence of any driver) can rescue survival of gbb¹/gbb² animals to 3rd instar or pupal stage. The additional presence of Scer\GAL4^G14 rescues bouton density and spontaneous mini-EJP (excitatory junctional potential) frequency to wild-type levels, and partially rescues spontaneous mini-EJP amplitude, evoked EJP frequency and levels of neurotransmitter release at synapses. Essentially identical results are seen when Scer\GAL4^BG380 is used instead (although bouton density not measured). However, when Scer\GAL4^elav-C155 is used there is only a slight rescue of bouton density, but the frequency and amplitude of spontaneous mini-EJPs, the amplitude of evoked EJPs and the levels of neurotransmitter release at synapses are all rescued to wild-type levels.

(McCabe et al., 2003)

Images (0)

Mutant

Wild-type

Stocks (0)

Notes on Origin

Discoverer

Comments

Homozygotes and hemizygotes over Df(2R)b23 are phenotypically indistinguishable. The gbb alleles fall into a phenotypic series. Starting with the most severe alleles: gbb¹ = gbb² > gbb³ > gbb⁴.

(Wharton et al., 1999)

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (2)

Reported As

Symbol Synonym

ac-17

(Wharton et al., 1999)

gbb²

(Aponte-Santiago et al., 2020, Berke et al., 2019, Kamimura et al., 2019, Kanai et al., 2018, Akbergenova and Littleton, 2017, Shilts and Broadie, 2017, Becker et al., 2016, Sulkowski et al., 2016, James et al., 2014, Sulkowski et al., 2014, Akiyama et al., 2012, Smith et al., 2012, Ball et al., 2010, Ellis et al., 2010, Baines, 2004)

Name Synonyms

Secondary FlyBase IDs

References (19)

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