FlyBase Allele Report: Dmel\robo1[unspecified]

General Information

Symbol

Dmel\robo1^unspecified

Species

D. melanogaster

Name

FlyBase ID

FBal0086356

Feature type

allele

Associated gene

Dmel\robo1

Associated Insertion(s)

Carried in Construct

Key Links

Allele class

Mutagen

Nature of the Allele

Allele class

Mutagen

Progenitor genotype

Cytology

Description

FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.

(FlyBase Curators, 2025-)

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

(Grueber et al., 2007, Bhat, 2005, Englund et al., 2002, Stevens and Jacobs, 2002)

abnormal neuroanatomy | embryonic stage

(Spitzweck et al., 2010)

abnormal neuroanatomy | embryonic stage 16

(Coleman et al., 2010)

Phenotype Manifest In

Detailed Description

Statement

Reference

Stage 16 robo^unspecified embryos show thinning of the longitudinal connectives and thickening of the commissures. They exhibit a severe phenotype in which the medial fascicle repeatedly crosses the midline. Ap neurons also exhibit crossing defects but collapse on the midline.

(Coleman et al., 2010)

The medial longitudinal tracts inappropriately collapse at the midline in mutant embryos.

(Bhat, 2005)

All ganglionic branches migrate into the ventral nerve cord and the position of GB1 nucleus is not significantly affected in mutant embryos. At the midline, 29% of ganglionic branches cross the midline, while 26% migrate unusually close to the midline, where they stall or turn to migrate dorsally. The three longitudinal connectives are severely disrupted by loops of axons crossing the midline several times. GB1 crosses the midline only once and migrates along the longitudinal tracts of the contralateral hemisegment.

(Englund et al., 2002)

The medial-most Fas2-positive fascicle collapses at the midline in mutant embryos.

(Schimmelpfeng et al., 2001)

Loss of robo causes sever midline crossing of the midline, thickening of the commissures and reduction of the longitudinal connectives between segments. Con staining axons are show the expected pair of pathways, but axons in the medial of the two pathways appear to ectopically cross the midline. In a robo^unspecified mutant the axons in the medial Fas2 pathway cross and recross the midline, while the axons in the intermediate and lateral Fas2 pathways do not cross the midline.

(Simpson et al., 2000)

In embryos, far too many axons cross and recross the midline, resulting in commissures that are much thicker than wild-type and thinner longitudinal connectives.

(Bashaw and Goodman, 1999)

No gross dentritic defects are seen in mutant embryos.

(Gao et al., 1999)

Fas2-positive nerve bundles frequently cross the midline in mutant embryos, in contrast to wild-type.

(Hummel et al., 1999)

robo^unspecified embryos have an increased number of axons in the commissures, coincident with a reduction of the number of axons in the longitudinal connectives. The commissures are thicker than normal and partially fused, while the longitudinals are thinner and pulled closer towards the midline than normal. The pCC growth cone extends anteriorly and then crosses the midline, where it fasciculates with its contralateral homologue. The pCC pathway projects back and forth across the midline, forming a circular pattern, in contrast to wild-type embryos where it projects longitudinally and does not cross the midline. The SP1 growth cone extends across the midline, adheres to the axon and cell body of its contralateral homologue, and turns to project anteriorly, as in wild-type embryos. However in robo^unspecified embryos, as the SP1 growth cone extends anteriorly into the next segment, it typically moves towards the midline and adheres to the axon of its contralateral homologue just on the other side of the midline. The SP1 axons freely cross and recross the midline in these embryos.

(Kidd et al., 1998)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Enhanced by

Statement

Reference

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 | dominant phenotype, enhanceable by Scer\GAL4^ap-md544/kuz^DN.UAS

(Coleman et al., 2010)

robo1^unspecified has abnormal neuroanatomy phenotype, enhanceable by sli²

(Stevens and Jacobs, 2002)

robo1^unspecified, robo2⁴ has abnormal neuroanatomy phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo2⁴ has abnormal neuroanatomy phenotype, enhanceable by Abl⁴/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo2⁵ has abnormal neuroanatomy phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo3¹ has abnormal neuroanatomy phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

NOT Enhanced by

Statement

Reference

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 phenotype, non-enhanceable by kuz^unspecified

(Coleman et al., 2010)

Suppressed by

Statement

Reference

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 phenotype, suppressible by fra::robo1^{U.UAS.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 phenotype, suppressible by fra::robo1^{UAS.FR.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{U.UAS.Tag:MYC}

(Coleman et al., 2010)

robo1^unspecified has abnormal neuroanatomy | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{UAS.FR.Tag:MYC}

(Coleman et al., 2010)

Enhancer of

Statement

Reference

robo[+], robo1^unspecified, Scer\GAL4^ap-md544 is an enhancer of abnormal neuroanatomy | embryonic stage 16 phenotype of Scer\GAL4^ap-md544, kuz^DN.UAS

(Coleman et al., 2010)

sli^unspecified/robo1^unspecified is an enhancer of abnormal neuroanatomy | embryonic stage 16 phenotype of kuz^unspecified

(Coleman et al., 2010)

robo1^unspecified is an enhancer of abnormal neuroanatomy phenotype of sli²

(Stevens and Jacobs, 2002)

Other

Statement

Reference

robo1^unspecified, robo2⁴ has abnormal neuroanatomy phenotype

(Wills et al., 2002)

robo1^unspecified, robo2⁵ has abnormal neuroanatomy phenotype

(Wills et al., 2002)

robo1^unspecified, robo3¹ has abnormal neuroanatomy phenotype

(Wills et al., 2002)

Phenotype Manifest In

Enhanced by

Statement

Reference

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, enhanceable by Scer\GAL4^ap-md544/kuz^DN.UAS

(Coleman et al., 2010)

robo1^unspecified has commissure | embryonic stage 16 phenotype, enhanceable by Scer\GAL4^ap-md544/kuz^DN.UAS

(Coleman et al., 2010)

robo1^unspecified has fascicle phenotype, enhanceable by sli²

(Stevens and Jacobs, 2002)

robo1^unspecified, robo2⁴ has presumptive embryonic/larval central nervous system phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo2⁴ has presumptive embryonic/larval central nervous system phenotype, enhanceable by Abl⁴/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo2⁵ has presumptive embryonic/larval central nervous system phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

robo1^unspecified, robo3¹ has presumptive embryonic/larval central nervous system phenotype, enhanceable by Abl²/Abl[+]

(Wills et al., 2002)

robo1^unspecified has larval longitudinal connective phenotype, enhanceable by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified has presumptive embryonic/larval central nervous system phenotype, enhanceable by lea[+]/robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified has larval longitudinal connective phenotype, enhanceable by lea[+]/robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified has larval ventral nerve cord phenotype, enhanceable by lea[+]/robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified has presumptive embryonic/larval central nervous system phenotype, enhanceable by robo2^unspecified/robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified has larval longitudinal connective phenotype, enhanceable by robo2^unspecified/robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified has larval ventral nerve cord phenotype, enhanceable by robo2^unspecified/robo2^unspecified

(Simpson et al., 2000)

NOT Enhanced by

Statement

Reference

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, non-enhanceable by kuz^unspecified

(Coleman et al., 2010)

robo1^unspecified has commissure | embryonic stage 16 phenotype, non-enhanceable by kuz^unspecified

(Coleman et al., 2010)

robo1^unspecified has larval ventral nerve cord commissure phenotype, non-enhanceable by comm^unspecified

(Rajagopalan et al., 2000)

robo1^unspecified, robo2^unspecified has presumptive embryonic/larval central nervous system phenotype, non-enhanceable by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval ventral nerve cord phenotype, non-enhanceable by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval ventral nerve cord commissure phenotype, non-enhanceable by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval longitudinal connective phenotype, non-enhanceable by comm^Δe39

(Simpson et al., 2000)

Suppressed by

Statement

Reference

robo1^unspecified has commissure | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{U.UAS.Tag:MYC}

(Coleman et al., 2010)

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{UAS.FR.Tag:MYC}

(Coleman et al., 2010)

robo1^unspecified has commissure | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{UAS.FR.Tag:MYC}

(Coleman et al., 2010)

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, suppressible by fra::robo1^{U.UAS.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has commissure | embryonic stage 16 phenotype, suppressible by fra::robo1^{U.UAS.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, suppressible by fra::robo1^{UAS.FR.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has commissure | embryonic stage 16 phenotype, suppressible by fra::robo1^{UAS.FR.Tag:MYC}/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified has larval longitudinal connective | embryonic stage 16 phenotype, suppressible by Scer\GAL4^ap-md544/fra::robo1^{U.UAS.Tag:MYC}

(Coleman et al., 2010)

NOT suppressed by

Statement

Reference

robo1^unspecified has ganglionic tracheal branch primordium phenotype, non-suppressible by robo2^{UAS.Tag:HA,Tag:SS(wg)}/Scer\GAL4^bs.Term

(Englund et al., 2002)

robo1^unspecified, robo2^unspecified has presumptive embryonic/larval central nervous system phenotype, non-suppressible by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval ventral nerve cord phenotype, non-suppressible by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval ventral nerve cord commissure phenotype, non-suppressible by comm^Δe39

(Simpson et al., 2000)

robo1^unspecified, robo2^unspecified has larval longitudinal connective phenotype, non-suppressible by comm^Δe39

(Simpson et al., 2000)

Enhancer of

Statement

Reference

robo[+], robo1^unspecified, Scer\GAL4^ap-md544 is an enhancer of larval longitudinal connective | embryonic stage 16 phenotype of Scer\GAL4^ap-md544, kuz^DN.UAS

(Coleman et al., 2010)

robo[+], robo1^unspecified, Scer\GAL4^ap-md544 is an enhancer of commissure | embryonic stage 16 phenotype of Scer\GAL4^ap-md544, kuz^DN.UAS

(Coleman et al., 2010)

sli^unspecified/robo1^unspecified is an enhancer of larval longitudinal connective | embryonic stage 16 phenotype of kuz^unspecified

(Coleman et al., 2010)

sli^unspecified/robo1^unspecified is an enhancer of commissure | embryonic stage 16 phenotype of kuz^unspecified

(Coleman et al., 2010)

robo1^unspecified is an enhancer of fascicle phenotype of sli²

(Stevens and Jacobs, 2002)

robo1^unspecified/robo1^unspecified is an enhancer of larval ventral nerve cord phenotype of robo2^x135

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of presumptive embryonic/larval central nervous system phenotype of robo2^unspecified

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of larval longitudinal connective phenotype of robo2^unspecified

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of larval ventral nerve cord phenotype of robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified/robo1^unspecified is an enhancer of presumptive embryonic/larval central nervous system phenotype of robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified/robo1^unspecified is an enhancer of larval longitudinal connective phenotype of robo2^unspecified

(Simpson et al., 2000)

robo1^unspecified/robo1^unspecified is an enhancer of larval ventral nerve cord phenotype of robo2^unspecified

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of presumptive embryonic/larval central nervous system phenotype of robo2^x135

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of larval longitudinal connective phenotype of robo2^x135

(Simpson et al., 2000)

robo[+]/robo1^unspecified is an enhancer of larval ventral nerve cord phenotype of robo2^x135

(Simpson et al., 2000)

robo1^unspecified/robo1^unspecified is an enhancer of presumptive embryonic/larval central nervous system phenotype of robo2^x135

(Simpson et al., 2000)

robo1^unspecified/robo1^unspecified is an enhancer of larval longitudinal connective phenotype of robo2^x135

(Simpson et al., 2000)

Other

Statement

Reference

Additional Comments

Genetic Interactions

Statement

Reference

kuz^unspecified does not enhance the FasII axon midline crossing phenotype seen in robo^unspecified stage 16 embryos.

Pan-neuronal expression of fra::robo^{U.Scer\UAS.T:Hsap\MYC} under the control of Scer\GAL4^elav.PLu partially suppresses the midline crossing phenotype seen in robo^unspecified mutants. Many of the most medial FasII axons still cross the midline.

Pan-neuronal expression of fra::robo^{Scer\UAS.FR.T:Hsap\MYC} under the control of Scer\GAL4^elav.PLu partially suppresses the midline crossing phenotype seen in robo^unspecified mutants. Many of the most medial ipsilateral axons still cross the midline.

Expression of fra::robo^{U.Scer\UAS.T:Hsap\MYC} in the ap neurons under the control of Scer\GAL4^ap-md544 partially suppresses the midline crossing phenotype seen in robo^unspecified mutants. In some segments the ap axon tracts on either side of the midline are fused and collapsed on the midline.

Expression of fra::robo^{Scer\UAS.FR.T:Hsap\MYC} in the ap neurons under the control of Scer\GAL4^ap-md544 partially rescues the midline crossing phenotype seen in robo^unspecified mutants. Some segments have ap axon tracts on both sides of the midline.

One copy of robo^unspecified enhances the ectopic midline crossing phenotype seen when kuz^DN.Scer\UAS is expressed in the ipsilateral ap neurons of stage 16 embryos under the control of Scer\GAL4^ap-md544.

Expression of kuz^DN.Scer\UAS in the ipsilateral ap neurons under the control of Scer\GAL4^ap-md544 enhances the ectopic midline crossing phenotype seen in robo^unspecified/+ stage 16 embryos.

(Coleman et al., 2010)

The positioning of the longitudinal tracts in robo^unspecified ; NetA^unspecified NetB^unspecified double mutant embryos is as seen in NetA^unspecified NetB^unspecified single mutant embryos.

(Bhat, 2005)

Longitudinal tracts collapse at the midline in sli^unspecified robo^unspecified double mutant embryos.

(Bossing and Brand, 2002)

21% of ganglionic branches stall outside the central nervous system in robo^unspecified lea^unspecified double mutant embryos, 31% cross the midline and 45% are misrouted. The longitudinal axons collapse along the midline. The midline crossing phenotype of the ganglionic branches in robo^unspecified mutant embryos is not rescued by expression of lea^{Scer\UAS.T:Ivir\HA1,T:wg} under the control of Scer\GAL4^bs.Term. Expression of sli^Scer\UAS.cKa under the control of Scer\GAL4^twi.PG in a robo^unspecified background results in the formation of additional visceral branches from metamere T3 and also from other tracheal metameres.

(Englund et al., 2002)

sli² robo^unspecified double mutants exhibit midline guidance errors in 44% of embryonic segments (as assayed with Fas2). The heterozygote Df(1)NP5 phenotype is not enhanced in embryos also heterozygous for robo^unspecified. In contrast, the frequency of midline guidance errors is increased in robo^unspecified/+ embryos also heterozygous for Df(1)NP5.

(Stevens and Jacobs, 2002)

The frequency of ectopic crossing of the midline by axons in the central nervous system seen in robo^unspecified lea^robo2-4 embryos is increased by Abl²/+ or Abl⁴/+. The frequency of ectopic crossing of the midline by axons in the central nervous system seen in robo^unspecified lea^robo2-5 embryos is increased by Abl²/+. The frequency of ectopic crossing of the midline by axons in the central nervous system seen in robo^unspecified robo3¹ embryos is increased by Abl²/+.

(Wills et al., 2002)

lea^unspecified ; robo^unspecified double mutant embryos show an almost complete collapse of axon fascicles at the central nervous system midline. robo^unspecified homozygotes that are also heterozygous for kuz^unspecified have a central nervous system (CNS) phenotype similar to that of robo^unspecified single mutants. The overall axon phenotype of robo^unspecified kuz^unspecified double homozygotes is slightly more severe than that of robo^unspecified single mutants as axons are frequently detected running along the CNS midline.

(Schimmelpfeng et al., 2001)

The addition of comm^unspecified to robo^unspecified embryos does not affect the number of commissure crossing the midline.

(Rajagopalan et al., 2000)

Injection of lea^cSa and lea^a.cSa as dsRNA into robo^unspecified embryos results in embryos with only a single Fas2-expressing longitudinal fascicle, which runs along the midline. Injection of robo3^cSa and robo3^a.cSa as dsRNA into robo^unspecified embryos results in embryos with 2 Fas2-expressing longitudinal fascicles; the medial fascicle, which is thicker than normal as it contains axons that are normally part of the intermediate fascicle, and the lateral fascicle. The combined medial and intermediate fascicle ectopically crosses and recrosses the midline. The lateral fascicle remains ipsilateral.

(Simpson et al., 2000)

Embryos homozygous mutant for robo^unspecified and lea^unspecified show a compressed midline where all the axons approach the midline and cannot leave. The addition of comm^Δe39 does not effect this phenotype. Embryos heterozygous for lea^unspecified/+ and homozygous robo^unspecified, show ectopic crossing of the medial Fas2 pathway but the medial pathway collapses entirely onto the midline. Embryos heterozygous for robo^unspecified/+ and homozygous lea^unspecified much more ectopic crossing is sen tha seen in lea^unspecified homozygotes. In a robo^unspecified/comm^Δe39 double mutant embryo, the intermediate Fas2 pathways is also perturbed and can be seen crossing the midline.

(Simpson et al., 2000)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Rescued by

robo1^unspecified is rescued by robo1^UAS.Tag:MYC/Scer\GAL4^ap-md544

(Coleman et al., 2010)

Partially rescued by

robo1^unspecified is partially rescued by robo1^UAS.Tag:MYC/Scer\GAL4^elav.PLu

(Coleman et al., 2010)

robo1^unspecified is partially rescued by Scer\GAL4^elav-C155/robo1^UAS.cKa

(Englund et al., 2002)

robo1^unspecified is partially rescued by Scer\GAL4^bs.Term/robo1^UAS.cKa

(Englund et al., 2002)

Not rescued by

robo1^unspecified is not rescued by robo1^ΔCC2CC3.UAS/Scer\GAL4^elav.PLu

(Fan et al., 2003)

Comments

Pan-neuronal expression of robo^{Scer\UAS.T:Hsap\MYC} under the control of Scer\GAL4^elav.PLu partially rescues the midline crossing phenotype seen in robo^unspecified stage 16 embryos. Some ectopic crossing of FasII axons is still seen.

Expression of robo^{Scer\UAS.T:Hsap\MYC} in the ap neurons under the control of Scer\GAL4^ap-md544 rescues the midline crossing phenotype seen in robo^unspecified mutants.

(Coleman et al., 2010)

The characteristic robo^unspecified phenotype (crossing of the midline by Fas2-positive longitudinal axons) is not rescued if the embryos are also heterozygous for robo^{lea.HR.T:Ivir\HA1}.

The characteristic robo^unspecified phenotype (crossing of the midline by Fas2-positive longitudinal axons) is not rescued if the embryos are also heterozygous for robo^{robo3.HR.T:Ivir\HA1}.

(Spitzweck et al., 2010)

Images (0)

Mutant

Wild-type

Stocks (0)

Notes on Origin

Discoverer

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (2)

Reported As

Symbol Synonym

robo1^unspecified

robo^unspecified

Name Synonyms

Secondary FlyBase IDs

References (18)

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