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General Information
D. melanogaster
FlyBase ID
Feature type
Also Known As
Df(1)X1, X-1
Computed Breakpoints include
Sequence coordinates
Member of large scale dataset(s)
Nature of Aberration
Cytological Order
Class of aberration (relative to wild type)
Class of aberration (relative to progenitor)
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data

l(1)20Ca << bk1 << l(1)20Cb << bb << bk2 << l(1)carot3

Genetic mapping information
Comments on Cytology

Deletion breakpoints are distal to or within l(1)20Cb and proximal to the nucleolus organiser.

Deficient for most of the basal X heterochromatin including bb and some proximal euchromatic loci.

Left limit of break 1 from non-inclusion of l(1)20Ca (FBrf0020833) Right limit of break 1 from inclusion of l(1)20Cb (FBrf0034331) Left limit of break 2 from inclusion of ABO-X (FBrf0076047) Right limit of break 2 from polytene analysis (citation unavailable)

Sequence Crossreferences
DNA sequence
Protein sequence
Gene Deletion and Duplication Data
Genes Deleted / Disrupted
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

    Df(2R)Su(z)2-1.b8 suppresses meiotic drive of the Y chromosome in Df(1)X-1 males compared to controls.

    Males carrying Df(1)X-1 /Dp(1;Y)BSYy+ show three effects; progeny yield is reduced, X-Y non-disjunction is high, and reciprocal meiotic products are recovered unequally.

    The frequency of X-Y nondisjunction seen in Df(1)X-1/Dp(1;Y)BSYy+ males is increased by bbr10Δ3.1A-2, bbr10Δ3 and bbt13.2, but is not altered by bbr10Δ3.1A-1 or bbr12.

    Fertile when in combination with Dp(1;Y)BSYy+and sterile in combination with Dp(1;Y)y+mal126 or Dp(1;Y)mal+.

    Heterozygotes with Dp(1;Y)BSYy+ are fertile, weakly fertile with Dp(1;Y)y+mal126 and sterile with Dp(1;Y)y+mal+.

    NOT in combination with other aberrations

    Df(1)X-1 males show a slight increase (<3-fold) in second-chromosome nondisjunction and a large (>700 fold) increase in XY nondisjunction. Unlike wild-type cells, XY nondisjunction is independent of the frequency of sex chromosome nondisjunction in Df(1)X-1 cells. Nondisjunctional second chromosome pairs are as likely to be at the pole opposite the X chromosome or that opposite the Y chromosome in Df(1)X-1 mutants, while they are more likely to be opposite the Y in wild-type cells. Likewise, nondisjoined XY and nondisjoined second chromosomes segregate independently from one another in Df(1)X-1 cells. Df(1)X-1 cells have a similar meiotic drive to wild type. Df(1)X-1 males are sick and not fully fertile.

    Homozygous females and hemizygous males are not viable.

    male viable with BSYy+ fertile with BSYy+ male viable with Dp(1;Y)y+mal+. male sterile with Dp(1;Y)y+mal+.

    Stocks (2)
    Notes on Origin
    Balancer / Genotype Variants of the Aberration
    Separable Components
    Other Comments

    Heterozygote males are inviable due to the proximal X euchromatin deletion.

    Synonyms and Secondary IDs (5)
    References (24)