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General Information
Symbol
Dmel\NAx-59b
Species
D. melanogaster
Name
FlyBase ID
FBal0012853
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Ax59b, Ax59b8, Ax59b8.1
Key Links
Mutagen
Nature of the Allele
Mutagen
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Nucleotide change:

T3165542G

Amino acid change:

C972G | N-PA; C972G | N-PB

Reported amino acid change:

C972G

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology

Polytene chromosomes normal (Welshons).

Nature of the lesion
Statement
Reference

Amino acid replacement: C972G.

Replacement of Cys at amino acid position 972, within the 24th EGF-like repeat.

Mutant partially sequenced; correlated with single amino acid replacements within six adjacent EGF-homologous elements of the N protein; has Gly at residue 2057 characteristic of Oregon R rather than Ser of Canton S (Kelley, Kidd, Deutsch and Young, 1987). Cysteine replaced by glycine at residue 972 in EGF repeat 24; TGC --> GGC (Kelley, Kidd, Deutsch and Young, 1987). Some NAx-59b strains have acquired an eleven-base-pair deletion leading to chain termination downstream of the substitution at residue 972, which is independent of the NAx-59b lesion. Such double mutants show a typical N phenotype (Kelley, Kidd, Deutsch and Young, 1987).

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

NAx-59b homozygous clones always differentiate as epidermis when adjacent to wild type cells, all bristles along the border are wild type.

The Abruptex phenotype of heteroallelic combinations with viable Abruptex alleles is reduced at 29oC as compared to 25oC.

Neural precursors never form in the Ax class of N alleles. Cells mutant for Ax class alleles but with some neural potential are inhibited from becoming neural by their neighbours but do not themselves affect their neighbours, which can become neural. Homozygous mutant clones develop as epidermis, and this requires Dl function.

Clones in the thorax lack bristles.

Mutations of mam, bib and neur in an heterozygous condition had no effect on the expression of NAx-59d or NAx-59b except when coupled in cis with Nfa-g. The neurogenic mutations suppress the wing venation phenotype of N.

Heterozygotes lack the twin sensilla of the wing margin, and often lack the ventral sensillum of wing vein L3, the anterior cross vein sensillum and the three sensilla of wing vein L3.

Heterozygotes exhibit wing vein abnormalities.

Expression was suppressed by Dl mutations and enhanced by E(spl) and H mutations.

Developmental studies of Young have shown that NAx-59b is a pupal lethal (Kelley, Kidd, Deutsch and Young, 1987). Homozygotes and hemizygotes semi-lethal at 22oC; lethality approximates 100% at 25oC. Lethal in heterozygotes with N mutants but viable and fertile with recessive visibles at Notch. NAx-59b/NAx-59b; Dp(1;2)51b/+ are poorly viable and infertile and mutant phenotype is enhanced. NAx-59b/+; Dp(1;2)51b/+ females have diminished mutant expression compared to NAx-59b/+ females which in turn are similar to males Ax/Y; Dp(1;2)51b/+. In heterozygotes with spl at 25oC, the eye is reduced in size but is larger than in spl/spl, and eye roughness varies from very mild to undetectable. The report by Welshons that NAx-59b/spl did not express the split phenotype was an error caused by uncontrolled temperature variation. In cis heterozygotes, spl NAx-59b/++, expression of split is enhanced compared to NAx-59b/spl; the eyes are rough and reduced in size. No such enhancement is seen when Nfa-g is coupled to NAx-59b and in NAx-59b/Nfa-g, the expression of the recessive is very mild and frequently nonpenetrant (Welshons, 1971). NAx-59b is semi-lethal with NAx-9 and lethal with alleles NAx-16, NAx-E2, NAx-71d, NAx-1 and the addition of Dp(1;2)51b to heterozygotes of NAx-59b with NAx-9 and NAx-1 restores viability (Portin, 1975). The temperature sensitivity of the NAx-59b phenotype is strongest at 25oC; mutant expression decreases at both 18oC and 29oC, with the least mutant expression at 29oC (Portin, 1981). At 18oC, there is complementarity with all recessive visibles at Notch and strong Ax expression in every case except when heterozygous with Nfa-g. At 29oC, all heterozygotes are noncomplementary with the exception of nd; Ax expression is diminished. At 29oC, homozygotes or hemizygotes with Dp(1;2)51b are more viable than at 18oC or 25oC (Portin, 1977). At 25oC, wing-vein interruption and bristle loss increases with an increased dose of the mutant gene (Portin, 1981). Somatic crossing over yields twin spots on cuticular surface of flies, indicating that NAx-59b is not a primary cell lethal (Portin, 1980). NAx-59b placed on the map of the Notch locus between spl and Nnd-2;

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Other
Statement
Reference
Phenotype Manifest In
NOT Suppressor of
Statement
Reference

NAx-59b is a non-suppressor of microchaeta | ectopic | somatic clone phenotype of groE48

Other
Statement
Reference
Additional Comments
Genetic Interactions
Statement
Reference

NAx-59b groE48 double mutant clones do form ectopic microchaetae (as is seen in groE48 single mutant clones).

NAx-59b shi1 double mutant clones in the thorax induced during the larval stage at the restrictive temperature present a strong neurogenic phenotype (excess of bristles), at the permissive temperature they are completely devoid of bristles.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Partially rescued by

NAx-59b is partially rescued by N+tCos479

Comments

One copy of cosP{479BE} can rescue lethality, rescued individuals exhibit the N wing phenotype.

Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer

Green.

Comments
Comments

Abolishes the fng-N interaction through EGF22-36.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (22)