FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Allele: Dmel\Top235-1
Open Close
General Information
Symbol
Dmel\Top235-1
Species
D. melanogaster
Name
FlyBase ID
FBal0282333
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Key Links
Genomic Maps

Nature of the Allele
Progenitor genotype
Cytology
Description

Amino acid replacement: R197C.

Amino acid replacement: C347S.

Amino acid replacement: P465S.

Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Nucleotide change:

T19451124A

Amino acid change:

C347S | Top2-PA; C347S | Top2-PB

Reported amino acid change:

C347S

Comment:

The nucleotide position of the Cys to Ser mutation is ambiguous. It could be a TGC to AGC or TGC to TCC codon change. The codon change was not specified. The codon change has been annotated as TGC to AGC. One of three amino acid substitutions observed in mutant strain.

Nucleotide change:

C19451640T

Amino acid change:

R197C | Top2-PA; R197C | Top2-PB

Reported amino acid change:

R197C

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. One of three amino acid substitutions observed in mutant strain.

Nucleotide change:

C19450770T

Amino acid change:

P465S | Top2-PA; P465S | Top2-PB

Reported amino acid change:

P465S

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. One of three amino acid substitutions observed in mutant strain.

Variant Molecular Consequences
Associated Sequence Data
DNA sequence
Protein sequence
 
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
Phenotype Manifest In
Detailed Description
Statement
Reference

82% of Top235-1/Df(2L)Exel9043 animals survive to pupation.

Surviving Top217-6/Top235-1 females are sterile and lay very few eggs. The vast majority of the eggs laid no not undergo nuclear divisions. Strings of developing egg chambers are seen in the mutant females, but the ovaries are smaller than normal, disorganised and show evidence of egg chamber apoptosis. Complex defects are seen in the germaria, with both loss and gain of germline stem cells being seen.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement
Reference
Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Comments

Top235-1 shows interallelic complementation with a number of other Top2 alleles. When Top235-1 is supplied paternally, the viability in combination with each allele as follows (% adult viability of progeny is shown in parentheses): Top217-1 (46%), Top217-3 (31%), Top217-6 (71%), Top235-5 (78%), Top235-13 (85%). When Top235-1 is supplied maternally, the viability in combination with each allele as follows (% adult viability of progeny is shown in parentheses): Top217-1 (56%), Top217-3 (22%), Top217-6 (58%), Top235-5 (86%), Top235-13 (79%).

Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
Reported As
Symbol Synonym
Top235-1
Top235-1-1
Name Synonyms
Secondary FlyBase IDs
    References (1)