FB2026_03 , released September 17, 2026
Aberration: Dmel\Dp(1;f)20A
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General Information
Symbol
Dp(1;f)20A
Species
D. melanogaster
Name
FlyBase ID
FBab0024556
Feature type
free_duplication
Also Known As
20A
Computed Cytological Breakpoints (relative to progenitor)
Sequenced Breakpoints (relative to progenitor)
Member of large scale dataset(s)
Nature of Aberration
Cytological Order
Progenitor
Dp(1;f)γ238
(Cook et al., 1997, Murphy and Karpen, 1995, Murphy and Karpen, 1995)
Mutagen
gamma ray
(Cook et al., 1997, Murphy and Karpen, 1995, Murphy and Karpen, 1995)
Class of aberration (relative to wild type)
free_duplication
Class of aberration (relative to progenitor)
chromosomal_deletion
(Murphy and Karpen, 1995)
Cytological Breakpoints (relative to progenitor)
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data
Genetic mapping information
Comments
Comments on Cytology

Used in experiments that showed that efficient achiasmate homolog disjunction in female meiosis I requires 1000kb of overlap in the centric heterochromatin and is not affected by homologous euchromatin or overall size differences. Disjunction efficiency decreases linearly as heterochromatic overlap is reduced from 1000 to 430kb. Rescue experiments with nod transgenes showed that heterochromatin does not act solely to promote chromosome movement or spindle attachment. Centric heterochromatin seems to contain multiple pairing elements that act additively to initiate or maintain the proper alignment of achiasmate chromosomes in meiosis I.

(Karpen et al., 1996)

"Terminal" deletion.

(Murphy and Karpen, 1995)
Sequence Crossreferences
DDBJ / EMBL / GenBank
DNA sequence
Protein sequence
Gene Deletion and Duplication Data
Genes Deleted / Disrupted
Complementation Data
Completely deleted / disrupted
y
(Murphy and Karpen, 1995)
Partially deleted / disrupted
Molecular Data
Completely deleted
Partially deleted
Genes NOT Deleted / Disrupted
Complementation Data
 
ry
(Murphy and Karpen, 1995)
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 (0)
    If no genes are listed here, it may be because the affected region is very large. The JBrowse insert above may show an error for the same reason, and other FlyBase tools such as CytoSearch may also fail for large regions. You can contact FlyBase for more help.
    In these cases, there will be no "Export to Hitlist" button to the left.
    Phenotypic Data
    In combination with other aberrations

    Dp(1;f)γ878/Dp(1;f)20A heterozygotes increases y+ expression, to 19% of full Dp(1;f)γ158 trans-suppression. y+ expression is quantitated in triple row bristles.

    (Donaldson and Karpen, 1997)
    NOT in combination with other aberrations

    Transmission rate through females to progeny is 53% in the first 5 days of egg lay.

    (Cook et al., 1997)

    Transmitted from meiosis at 32% in nod3/nod+ females and 51% in wild type females.

    (Murphy and Karpen, 1995)
    Stocks (0)
    Notes on Origin
    Discoverer
     
    Balancer / Genotype Variants of the Aberration
     
    Separable Components
     
    Other Comments
     

    Minichromosome is 1.115kb in length.

    (Cook et al., 1997)

    Contains 800kb of centric heterochromatin in inverted orientation.

    (Donaldson and Karpen, 1997)

    Monosome transmission behaviour from both male and female parents is stable demonstrating normal transmission and normal centromere function.

    (Murphy and Karpen, 1995)
    Synonyms and Secondary IDs (3)
    Reported As
    Symbol Synonym
    20A
    (Cook et al., 1997, Donaldson and Karpen, 1997, Murphy and Karpen, 1995)
    Dp(1;f)20A
    Dp(1;f)γ20A
    Name Synonyms
    Secondary FlyBase IDs
    • FBab0024057
    References (5)