FlyBase Allele Report: Dmel\chic[sand-1]

General Information

Symbol

Dmel\chic^sand-1

Species

D. melanogaster

Name

FlyBase ID

FBal0032639

Feature type

allele

Associated gene

Dmel\chic

Associated Insertion(s)

Carried in Construct

Also Known As

chic^sand1

Key Links

Allele class

hypomorphic allele - genetic evidence

Mutagen

ethyl methanesulfonate

Nature of the Allele

Allele class

hypomorphic allele - genetic evidence

(van Vactor et al., 1993)

Mutagen

ethyl methanesulfonate

(van Vactor et al., 1993)

Progenitor genotype

Cytology

Description

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

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 ( 0 )

Disease

Interaction

References

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

Disease-implicated variant(s)

Phenotypic Data

Phenotypic Class

abnormal neuroanatomy | embryonic stage

(Kim et al., 2001)

lethal | recessive

(Wills et al., 1999, van Vactor et al., 1993)

Phenotype Manifest In

egg

(Wills et al., 1999)

larval intersegmental nerve

(Kim et al., 2001)

larval longitudinal connective

(Kim et al., 2001)

motor neuron | embryonic stage

(Wills et al., 1999)

Detailed Description

Statement

Reference

Mutants do not exhibit a midline crossover phenotype in the pCC/MP2 pathway axons.

(Fritz and VanBerkum, 2002)

The pCC/MP2 pathway forms correctly in homozygous embryos, although the cord may be slightly disorganised.

The longitudinal connectives are slightly disorganised in homozygous embryos, but no axons cross the midline inappropriately.

Homozygous embryos show motor branch truncations, especially the branches of ISNb and ISN. In 76% of hemisegments of the mutant embryos, the ISNb axons fail to extend to muscle 12 and instead stop at earlier choice points beneath muscles 6/7 or 13.

(Kim et al., 2001)

chic^sand-1/chic⁰¹³²⁰ females fail to lay eggs. Lethal in combination with chic²²¹. Embryonic motoneurons extend out into the periphery in chic^sand-1/Df(2L)GpdhA embryos, correctly following their initial trajectories, but the growth cones arrest at branching choice points before reaching their final muscle targets. This premature arrest is seen in all motor branches. The stalled growth cones have numerous filopodia and are as large if not larger than their wild-type counterparts. Hemizygous chic^sand-1 embryos show a substantial rescue of the "stranded" axonal phenotype if Dp(2;2)C619 (a duplication of the chic locus) is supplied maternally. Axon growth from homozygous dissected nerve cords cultured in vitro is reduced compared to wild-type.

(Wills et al., 1999)

Defective in navigation through a specific choice point during intersegmental nerve and segmental nerve b pathfinding. Intersegmental nerve projections also prematurely terminated. Subtle defects in CNS pathfinding also evident.

(van Vactor et al., 1993)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Suppressed by

Statement

Reference

chic^sand-1 has abnormal neuroanatomy | embryonic stage phenotype, suppressible by Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

Suppressor of

Statement

Reference

chic^sand-1 is a suppressor of abnormal neuroanatomy | embryonic stage phenotype of Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

Phenotype Manifest In

Suppressed by

Statement

Reference

chic^sand-1 has larval intersegmental nerve phenotype, suppressible by Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

Suppressor of

Statement

Reference

chic^sand-1 is a suppressor of dMP2 neuron phenotype of Rac1^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of pCC neuron phenotype of Rac1^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of vMP2 neuron phenotype of Rac1^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of dMP2 neuron phenotype of Cdc42^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of vMP2 neuron phenotype of Cdc42^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of pCC neuron phenotype of Cdc42^V12.UAS, Scer\GAL4^ftz.ng

(Fritz and VanBerkum, 2002)

chic^sand-1 is a suppressor of pCC neuron phenotype of Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

chic^sand-1 is a suppressor of vMP2 neuron phenotype of Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

NOT Suppressor of

Statement

Reference

chic^sand-1 is a non-suppressor of larval intersegmental nerve phenotype of Khc::Ggal\MLCK^KA.ftz

(Kim et al., 2001)

Additional Comments

Genetic Interactions

Statement

Reference

The addition of chic^sand-1 to any of Rho1^N19.Scer\UAS, Rho1^V14.Scer\UAS, Rac1^N17.Scer\UAS or Cdc42^N17.Scer\UAS has no effect on their midline crossover phenotypes in the pCC/MP2 pathway axons. The addition of chic^sand-1 to Rac1^V12.Scer\UAS suppresses the midline crossover phenotypes in the pCC/MP2 pathway axons. 57.3% of embryos exhibit the phenotype. An average of 1.5 crossovers are seen per embryo. The addition of chic^sand-1 to Cdc42^V12.Scer\UAS suppresses the midline crossover phenotypes in the pCC/MP2 pathway axons. 45.5% of embryos exhibit the phenotype. An average of 1.9 crossovers are seen per embryo.

(Fritz and VanBerkum, 2002)

The abnormal midline crossing of axons seen in robo¹ heterozygotes is suppressed if the embryos are also heterozygous for chic^sand-1. However, chic^sand-1 robo¹ double homozygotes show a severe disruption of the nerve cord. Large numbers of axons cross the midline within segment boundaries and major gaps are seen in the longitudinal connectives.

(Kim et al., 2001)

Xenogenetic Interactions

Statement

Reference

Pioneer neurons of the pCC/MP2 pathway stall less often and form the pathway with fewer errors in Khc::Ggal\MLCK^KA.ftz chic^sand-1 double mutant embryos compared to Khc::Ggal\MLCK^KA.ftz single mutant embryos; only 15% of hemisegments have gaps in the pCC/MP2 pathway in double homozygous embryos and only 18% of hemisegments have gaps in the pCC/MP2 pathway in Khc::Ggal\MLCK^KA.ftz chic^sand-1/Khc::Ggal\MLCK^KA.ftz + embryos.

Only 16% of double homozygous Khc::Ggal\MLCK^KA.ftz chic^sand-1 embryos and 18% of Khc::Ggal\MLCK^KA.ftz chic^sand-1/Khc::Ggal\MLCK^KA.ftz + embryos show abnormal midline crossing of axons within the pCC/MP2 pathway (compared to 51% of Khc::Ggal\MLCK^KA.ftz single homozygotes).

In Khc::Ggal\MLCK^KA.ftz chic^sand-1 embryos, all branches of the motor neuron projection are at least partially restored to wild type. Innervation to muscle 12 by the ISNb branch is restored from 24% of hemisegments in chic^sand-1 single mutants to 96% of hemisegments in the Khc::Ggal\MLCK^KA.ftz chic^sand-1 double mutants. Similarly, in 88% of double mutant hemisegments, the ISN branch extends beyond the third branch point to innervate the dorsal-most muscles (1 and 2), compared to only 48% in chic^sand-1 single mutants. The subtle overextension phenotype observed at muscle 12 of Khc::Ggal\MLCK^KA.ftz single mutants is still seen in the double mutants.

(Kim et al., 2001)

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 (5)

Reported As

Symbol Synonym

chi^sand-1

chic^sand-1

chic^sand1

(Kim et al., 2001, Wills et al., 1999)

chic^sand

(Fritz and VanBerkum, 2002)

sand¹

Name Synonyms

Secondary FlyBase IDs

References (4)

Report Sections

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