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General Information
D. melanogaster
FlyBase ID
Feature type
Also Known As
Computed Breakpoints include


Sequence coordinates
Member of large scale dataset(s)
Nature of Aberration
Cytological Order

| 1A4 - 20 . 20F - 20A1 |

Class of aberration (relative to wild type)
Class of aberration (relative to progenitor)
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data
Genetic mapping information
Comments on Cytology

All limits from polytene analysis (citation unavailable)

Sequence Crossreferences
DNA sequence
Protein sequence
Gene Deletion and Duplication Data
Genes Deleted / Disrupted
Complementation Data
Completely deleted / disrupted
Partially deleted / disrupted
Molecular Data
Completely deleted
Partially deleted
Genes NOT Deleted / Disrupted
Complementation Data
Molecular Data
Genes Duplicated
Complementation Data
Completely duplicated
Partially duplicated
Molecular Data
Completely duplicated
Partially duplicated
Genes NOT Duplicated
Complementation Data
Molecular Data
Affected Genes Inferred by Location
    Phenotypic Data
    In combination with other aberrations
    NOT in combination with other aberrations

    More viable than R(1)1; X/0 male survives. Ordinarily, ring elimination less than 1% (Battacharya, 1950, Proc. R. Soc. Edinburgh, B 64: 199-215; Braver and Blount, 1950, Genetics 35: 98), but nearly 20% of the first progeny of 11-day-old females crossed to ring-bearing males are gynandromorphs (Hannah, 1955, Z. Indukt. Abstamm. Vererbungsl. 86: 600-21). Number of male nuclei in eggs of gynandromorphs varies greatly, suggesting that loss of the ring X may occur more than once and that it may take place as late as the ninth cleavage (Zalokar, 1980, Cell 19: 133-41). Crossing over reduced in ring/rod heterozygote; only double crossovers recovered. Exceptional males result from 4-strand double exchange in R(1)2/+ female.

    Stocks (13)
    Notes on Origin

    Beadle, 34b (ring nature discovered by Boche).


    Induced on: C(1)RM y+.

    Balancer / Genotype Variants of the Aberration
    Separable Components
    Other Comments

    R(1)2 chromosome from Bowling Green stock center found to carry an allele of bb, named bbBG.

    Ring may open out spontaneously in stock <up>e.g., In(1)EN2</up>.

    Synonyms and Secondary IDs (3)
    Reported As
    Name Synonyms
    Secondary FlyBase IDs
      References (20)