FlyBase Allele Report: Dmel\robo1[4]

General Information

Symbol

Dmel\robo1⁴

Species

D. melanogaster

Name

FlyBase ID

FBal0032591

Feature type

allele

Associated gene

Dmel\robo1

Associated Insertion(s)

Carried in Construct

Also Known As

robo^z570, z570, robo⁴

Key Links

Genomic Maps

JBrowse

Allele class

amorphic allele - genetic evidence

loss of function allele

Mutagen

ethyl methanesulfonate

Nature of the Allele

Allele class

amorphic allele - genetic evidence

(Kidd et al., 1998)

loss of function allele

(Kidd et al., 1999)

Mutagen

ethyl methanesulfonate

(Kidd et al., 1998, Seeger et al., 1993)

Progenitor genotype

Cytology

Description

Nucleotide substitution: G1434A.

(Bosch, 2014.11.5)

Amino acid replacement: W478term.

(Bosch, 2014.11.5)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

point_mutation

2R:22,697,985..22,697,985 [-]

Nucleotide change:

G22697985A

Reported nucleotide change:

G1434A

Amino acid change:

W478term | robo1-PA; W478term | robo1-PC

Reported amino acid change:

W478term

Comment:

TGG to TGA nonsense mutation.

(Bosch, 2014.11.5)

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

(Bhat et al., 2007, Parsons et al., 2003)

abnormal neuroanatomy | embryonic stage (with Df(2R)BSC786)

(Manavalan et al., 2017)

lethal | recessive

(Bhat et al., 2007)

Phenotype Manifest In

central nervous system

(Bashaw et al., 2000)

dorsal vessel wall cell

(Santiago-Martinez et al., 2006)

ganglion mother cell GMC1-1a

(Mehta and Bhat, 2001)

larval abdominal lch5 neuron

(Parsons et al., 2003)

larval anterior commissure

(Bashaw et al., 2000)

larval DA1 motor neuron

(Wolf and Chiba, 2000)

larval longitudinal connective

(Bhat et al., 2007, Bashaw et al., 2000, Kidd et al., 1999)

larval longitudinal connective | embryonic stage (with Df(2R)BSC786)

(Manavalan et al., 2017)

larval posterior commissure

(Bashaw et al., 2000)

larval RP2 motor neuron

(Wolf and Chiba, 2000)

larval RP2 motor neuron | ectopic

(Mehta and Bhat, 2001)

larval segmental nerve sensory neuron

(Parsons et al., 2003)

larval thoracic lateral multidendritic neuron ldaA

(Parsons et al., 2003)

larval ventral nerve cord commissure

(Kidd et al., 1999)

lesA neuron

(Parsons et al., 2003)

pCC neuron

(Bashaw et al., 2000)

presumptive embryonic/larval muscle system

(Kidd et al., 1999)

RP2sib neuron

(Mehta and Bhat, 2001)

symmetrical commissure | embryonic stage (with Df(2R)BSC786)

(Manavalan et al., 2017)

Detailed Description

Statement

Reference

robo1⁴/Df(2R)BSC786 homozygous embryos exhibit severe defects in the longitudinal connective from 14h post-fertilization onwards, as compared to controls.

(Manavalan et al., 2017)

The intermediate and medial Fas2-positive longitudinal tracts are collapsed at the midline in mutant embryos.

48% of homozygous embryos hatch into first instar larvae and 3% of the embryos develop into the pupal stage, but none of these pupae eclose into adults.

(Bhat et al., 2007)

robo⁴ embryos show much milder defects compared to robo⁴, lea^X123 double mutant embryos: mispositioned cardioblasts are only occasionally seen.

(Santiago-Martinez et al., 2006)

Homozygous embryos show sensory axon defects; one or more axons from the lch5 cluster project inappropriately to join the v'ch1 axon or the v' cluster in 19% of hemisegments. In these hemisegments, the remaining lch5 axons project in a normal fashion to the intersegmental nerve. In addition, the axon of one of the lesA and ldaA neurons (usually the lesA neuron) follows the v'ch1 pathway in 24% of hemisegments. Occasionally (1% of hemisegments), v'ch1 or other v' cluster axons grow dorsally before turning back into the segmental nerve or inappropriately joining the intersegmental nerve.

(Parsons et al., 2003)

In robo⁴ homozygotes and robo⁴/Deficiency mutants GMC-1 and GMC1-1a are found to divide symmetrically to generate two RP2s and two aCCs at the expense of sib and pCC. The penetrance of the RP2 phenotype is about 2.3%.

(Mehta and Bhat, 2001)

robo⁴ mutants have a dramatically disrupted CNS axon scaffold, causing far too many axons to cross and recross the midline; anterior and posterior commissures appear to be much thicker or even fused together, and the longitudinal connectives are greatly reduced. The pCC neuron initially extends anteriorly, but instead of continuing its anterior trajectory as seen in wild-type, it turns and crosses the midline.

(Bashaw et al., 2000)

robo⁴ embryos form commissural tracts. Cell bodies of the RP3, RP2 and aCC neurons are present in all half-segments examined. Cell bodies of the RP2 and aCC neurons are displaced. Axon terminals are present on muscles 6 and 7 in 73% of half-segments, on muscle 12 in 76% of half-segments, muscle 2 in 90% of half-segments and muscle 1 in 98% of half-segments. The axon pathway of the RP3 neurons is normal in mutant embryos, and all RP3 neurons cross the midline, as in wild type. 19% of RP2 neurons cross the midline in mutant embryos, in contrast to wild-type embryos where they do not cross the midline. In all cases, subsequent growth cone guidance accuracy of the RP2 neurons is normal. 3% of aCC neurons cross the midline in mutant embryos, in contrast to wild-type embryos where they do not cross the midline. In all cases, subsequent growth cone guidance accuracy of the aCC neurons is normal.

(Wolf and Chiba, 2000)

Two many axons cross and recross the midline in the central nervous system (CNS) of robo⁴ embryos, resulting in thick and fuzzy commissures and longitudinals which are thinner than normal. Rarely, a single muscle can be seen extending inappropriately dorsally over the CNS. The ventral muscles are frequently attached more closely to the midline than in wild-type embryos.

(Kidd et al., 1999)

"Fuzzy commisure" phenotype in embryonic central nervous system.

(Seeger et al., 1993)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Enhanced by

Statement

Reference

robo1⁴/Df(2R)BSC786 has abnormal neuroanatomy | embryonic stage phenotype, enhanceable by Df(2L)ED108/Df(2L)ED108

(Manavalan et al., 2017)

Other

Statement

Reference

Dscam1⁰⁵⁵¹⁸, robo1⁴ has abnormal neuroanatomy | embryonic stage phenotype

(Hernández et al., 2023)

robo[+]/robo1⁴, sli² has abnormal neuroanatomy phenotype

(Parsons et al., 2003)

robo1⁴, sli² has abnormal neuroanatomy phenotype

(Parsons et al., 2003)

Phenotype Manifest In

Enhanced by

Statement

Reference

robo1⁴/Df(2R)BSC786 has larval longitudinal connective | embryonic stage phenotype, enhanceable by Df(2L)ED108/Df(2L)ED108

(Manavalan et al., 2017)

robo1⁴/Df(2R)BSC786 has symmetrical commissure | embryonic stage phenotype, enhanceable by Df(2L)ED108/Df(2L)ED108

(Manavalan et al., 2017)

Enhancer of

Statement

Reference

robo1⁴ is an enhancer of dorsal vessel wall cell | ectopic phenotype of Scer\GAL4^Mef2.PR, robo2^UAS.cSa, robo2^X123

(Santiago-Martinez et al., 2006)

robo[+]/robo1⁴ is an enhancer of larval longitudinal connective phenotype of RhoGAP93B¹

(Lundstrom et al., 2004)

robo[+]/robo1⁴ is an enhancer of ganglionic tracheal branch primordium phenotype of RhoGAP93B¹

(Lundstrom et al., 2004)

robo[+]/robo1⁴ is an enhancer of symmetrical commissure phenotype of ena^GC1/ena²¹⁰

(Bashaw et al., 2000)

robo[+]/robo1⁴ is an enhancer of larval longitudinal connective phenotype of ena^GC1/ena²¹⁰

(Bashaw et al., 2000)

robo[+]/robo1⁴ is an enhancer of pCC neuron phenotype of ena^GC1/ena²¹⁰

(Bashaw et al., 2000)

robo[+]/robo1⁴ is an enhancer of central nervous system phenotype of ena^GC1/ena²¹⁰

(Bashaw et al., 2000)

NOT Enhancer of

Statement

Reference

robo1⁴ is a non-enhancer of dorsal vessel wall cell | ectopic phenotype of Scer\GAL4^Mef2.PR, robo2^UAS.cSa

(Santiago-Martinez et al., 2006)

Suppressor of

Statement

Reference

robo1⁴ is a suppressor | partially of ganglionic tracheal branch primordium phenotype of Rac1^J11, Rac2^Δ

(Lundstrom et al., 2004)

NOT Suppressor of

Statement

Reference

robo1⁴ is a non-suppressor of dorsal vessel wall cell | ectopic phenotype of Scer\GAL4^Mef2.PR, robo2^UAS.cSa

(Santiago-Martinez et al., 2006)

Other

Statement

Reference

Dscam1⁰⁵⁵¹⁸, robo1⁴ has embryonic/larval frontal nerve | embryonic stage phenotype

(Hernández et al., 2023)

Scer\GAL4^Mef2.PR, robo1⁴, robo2^UAS.cSa has embryo | dorsal closure stage phenotype

(Santiago-Martinez et al., 2006)

robo1⁴, robo2^X123 has dorsal vessel wall cell phenotype

(Santiago-Martinez et al., 2006)

robo1⁴, robo2^X123 has embryonic pericardial cell phenotype

(Santiago-Martinez et al., 2006)

Scer\GAL4^Mef2.PR, robo1⁴, robo2^UAS.cSa, robo2^X123 has dorsal vessel wall cell phenotype

(Santiago-Martinez et al., 2006)

robo[+]/robo1⁴, sli² has larval abdominal lch5 neuron phenotype

(Parsons et al., 2003)

robo[+]/robo1⁴, sli² has lesA neuron phenotype

(Parsons et al., 2003)

robo[+]/robo1⁴, sli² has larval thoracic lateral multidendritic neuron ldaA phenotype

(Parsons et al., 2003)

robo1⁴, sli² has larval abdominal lch5 neuron phenotype

(Parsons et al., 2003)

robo1⁴, sli² has lesA neuron phenotype

(Parsons et al., 2003)

robo1⁴, sli² has larval thoracic lateral multidendritic neuron ldaA phenotype

(Parsons et al., 2003)

robo1⁴, sli¹ has presumptive embryonic/larval central nervous system phenotype

(Kidd et al., 1999)

robo1⁴, sli² has presumptive embryonic/larval central nervous system phenotype

(Kidd et al., 1999)

Additional Comments

Genetic Interactions

Statement

Reference

The defects in the longitudinal connective observed in late robo1⁴/Df(2R)BSC786 homozygous embryos are severely enhanced by Df(2L)ED108 homozygosity.

(Manavalan et al., 2017)

robo⁴, fra^unspecified double mutant embryos show a mixture of longitudinal tract phenotypes, ranging from a phenotype like that seen in the robo⁴ single mutant (collapsed tracts) to a phenotype like that seen in the fra^unspecified single mutant (tracts positioned further away from the midline than normal) and an intermediate phenotype, although the robo-like phenotype is predominant.

(Bhat et al., 2007)

Embryos mutant for both robo⁴ and lea^X123 show defects in cardioblast and pericardial cell positioning and alignment, similar to slit² embryos. The number of cardioblast nuclei that reach the dorsal midline in these embryos is approximately 86.2, compared to approximately 104 in wild type embryos.

Expression of lea^Scer\UAS.cSa in cardioblasts using Scer\GAL4^Mef2.PR in a robo⁴ mutant background results in similar defects as when lea^Scer\UAS.cSa is expressed using Scer\GAL4^Mef2.PR in an otherwise wild type background. Namely, a lateral shift of the row of cardioblasts away from the dorsal midline to a position normally occupied by pericardial cells while adhesion between these cells is maintained.

Embryos expressing lea^Scer\UAS.cSa under the control of Scer\GAL4^Mef2.PR in a robo⁴, lea^X123 double mutant background display gaps in rows of cardioblasts indicating a loss of adhesion between cardioblasts (as seen in robo⁴, lea^X123 double mutants) as well as the mispositioning of these cells away from the dorsal midline (as seen in lea^Scer\UAS.cSa, Scer\GAL4^Mef2.PR embryos).

Embryos expressing lea^Scer\UAS.cSa under the control of Scer\GAL4^Mef2.PR in a robo⁴, lea^X123 double mutant background exhibit mispositioning of cardioblasts away from the dorsal midline which is more severe as compared to expression of lea^Scer\UAS.cSa using Scer\GAL4^Mef2.PR in an otherwise wild type background; cardioblasts are displaced even more laterally, with cardioblasts and pericardial cells even being observed in somatic muscle territory.

Expression of lea^Scer\UAS.cSa under the control of Scer\GAL4^Mef2.PR in a robo⁴ mutant background results in a slight delay in dorsal closure: a slight gap between dorsal ectodermal cells is seen in late stage mutant embryos that is not observed in wild type embryos.

(Santiago-Martinez et al., 2006)

In RhoGAP93B¹/RhoGAP93B¹, robo⁴/+ embryos 9% of ganglionic branches cross the midline, as opposed to 1% in RhoGAP93B¹ homozygotes alone. robo⁴ partially suppresses the ganglionic branch phenotype seen in Rac1^J11, Rac2^Δ embryos.

(Lundstrom et al., 2004)

sli²/+ robo⁴/+ double heterozygotes have lch5 and lesA/ldaA axons misprojecting to the v'ch1 pathway in some hemisegments. No stalling of lch5 axons is seen and dorsal sensory axons have a normal morphology.

(Parsons et al., 2003)

26% of segments contain Fas2-positive neurons inappropriately crossing the midline in sli¹/robo⁴ double heterozygous embryos, in contrast to either single heterozygote which show defects in 0 or 1% of segments. 39% of segments contain Fas2-positive neurons inappropriately crossing the midline in sli²/robo⁴ double heterozygous embryos, in contrast to either single heterozygote which show defects in 1% of segments.

(Kidd et al., 1999)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Rescued by

robo1⁴ is rescued by robo1^{UAS.Tag:HA,Tag:SS(wg)}/Scer\GAL4^12.1

(Parsons et al., 2003)

Comments

Images (0)

Mutant

Wild-type

Stocks (1)

Bloomington

84237

P{PZ}Dscam1⁰⁵⁵¹⁸ robo1⁴/SM5

Notes on Origin

Discoverer

Induced on: Fas3 null chromosome.

(Kidd et al., 1998)

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (8)

Reported As

Symbol Synonym

Z570

(Kidd et al., 1998)

robo1⁴

(Manavalan et al., 2017, Alavi et al., 2016)

robo⁴

(Bosch, 2014.11.5, Manavalan et al., 2013, Bhat et al., 2007)

robo⁵⁷⁰

(Gonsior and Ismat, 2019)

robo^Z570

(Santiago-Martinez et al., 2006, Nicolas and Preat, 2005, Wolf and Chiba, 2000)

robo^null

(Mehta and Bhat, 2001)

robo^z570

(Singh et al., 2024, Lundstrom et al., 2004, Englund et al., 2002)

z570

(Simpson et al., 2000)

Name Synonyms

Secondary FlyBase IDs

References (21)

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