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General Information
Symbol
Dmel\chb4
Species
D. melanogaster
Name
FlyBase ID
FBal0104955
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
orbit4
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Cytology
Nature of the lesion
Statement
Reference

Imprecise excision of the P{lacW} element, resulting in a deletion extending from within the asparagine-synthetase gene to within the chb gene.

Caused by aberration
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 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Homozygous and chb2/chb4 embryos show ectopic crossing of the midline by axons in the central nervous system. pCC axons often orient towards the midline in mutant embryos (in contrast to wild type where pCC axons extend slightly away from the midline) and sometimes crosses the midline to meet its contralateral homologue. Mutant embryos occasionally show premature arrest of the ISNb axon, at the muscle 13 cleft.

Mitotic defects are seen in the cells of the larval central nervous system in chb4/chbS068607 flies. Polyploid metaphase figures (15%), diploid metaphase figures with hypercondensed chromosomes (4%) and circular metaphase figures (4%) are seen. The metaphase to anaphase ratio and the mitotic index is increased compared to wild type. Third instar chb4/chb2 larvae lack imaginal discs and have a small central nervous system. More than 80% of total metaphase figures are polyploid, and more than 30% of polyploid figures have greater than an 8N chromosome complement. Circular metaphase figures and anaphase figures cannot be detected.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement
Reference

chb4 has neuroanatomy defective phenotype, enhanceable by Abl2

chb4, robo11 has neuroanatomy defective phenotype, enhanceable by robo28

NOT Enhanced by
Statement
Reference

chb4, robo11 has neuroanatomy defective phenotype, non-enhanceable by robo31

Enhancer of
Statement
Reference

chb4 is an enhancer of neuroanatomy defective phenotype of Abl2

Suppressor of
Statement
Reference
Other
Phenotype Manifest In
Enhanced by
Statement
Reference

chb4 has intersegmental nerve phenotype, enhanceable by Abl2

chb4 has embryonic/larval neuron phenotype, enhanceable by Abl2

NOT Enhanced by
Statement
Reference

chb4, robo11 has embryonic/larval neuron phenotype, non-enhanceable by robo31

Enhancer of
Statement
Reference

chb4 is an enhancer of intersegmental nerve phenotype of Abl2

chb4 is an enhancer of embryonic/larval neuron phenotype of Abl2

Suppressor of
Statement
Reference
Other
Additional Comments
Genetic Interactions
Statement
Reference

The frequency of axons ectopically crossing the midline in chb4 Abl2 double homozygous embryos is substantially increased compared to the frequency seen in either single homozygote. chb4 Abl2 double homozygous embryos show an increased frequency of premature arrest of the ISNb axon compared to either single homozygote, with the arrest being seen at both the muscle 6/7 and the muscle 13 choice points. sli2 chb4 double heterozygous embryos have axons ectopically crossing the midline. capt10 chb4 double heterozygous embryos do not show a significant increase in axons ectopically crossing the midline compared to controls. robo1 chb4 double heterozygous embryos have axons ectopically crossing the midline. Heterozygosity for learobo2-8 enhances the frequency of axons ectopically crossing the midline that is seen in robo1 chb4 double heterozygous embryos. Heterozygosity for robo31 does not enhance the frequency of axons ectopically crossing the midline that is seen in robo1 chb4 double heterozygous embryos. The ISNb bypass phenotype caused by expression of AblScer\UAS.cFa under the control of Scer\GAL4elav.PLu is reduced by chb4/chb4.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (2)
Reported As
Symbol Synonym
Name Synonyms
Secondary FlyBase IDs
    References (2)