Open Close
General Information
D. melanogaster
Inversion (3R) Crossover suppressor
FlyBase ID
Feature type
Computed Breakpoints include


Sequence coordinates
3R:20,308,209..20,308,209 (In(3R)C:bk1)
Member of large scale dataset(s)
Nature of Aberration
Cytological Order
Class of aberration (relative to wild type)
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data

bk1 << tll << bk2

Genetic mapping information

Distal breakpoint is at the junction of subtelomeric and telomeric sequences distal to the end of the reference genome assembly.

The 5' end of this breakpoint corresponds to 3R:20308209 and the 3' end corresponds to 3R:20308213 ; the breakpoint contains a 5bp duplication of genome sequence, in addition to the inversion.

Breakpoint(s) molecularly mapped

Comments on Cytology

Left limit of break 1 from polytene analysis (FBrf0029349) Right limit of break 1 from polytene analysis (FBrf0026036) Limits of break 2 from polytene analysis (FBrf0029349)

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

    A positive correlation between the frequency of In(3R)C in a population and the frequency of individuals carrying extra bristles has been demonstrated. The correlation has also been demonstrated at the individual level.

    Homozygous viable. Crossing over in 3R reduced to 1% between centromere and ss, to 0.2% between ss and e; no crossovers between e and tip of 3R recovered except for rare doubles within inversion.

    Stocks (46)
    Notes on Origin

    Sturtevant, June 1913.


    One of 16 polymorphic inversions identified in the Drosophila Genetic Reference Panel (DGRP) freeze 2 lines.

    According to Craymer in FBrf0063385, e1 was isolated on In(3R)C and was never successfully separated from it. Most ebony alleles denoted simply as "e" without a specific allele designation can be traced back to Muller's e4. Most ebony mutations in Stock Center stocks designated as e1 are probably e4.

    e1 arose on In(3R)C and has never been separated from the inversion.

    Recovered as: Cosmopolitan inversion.

    Isolation: Koleika, Greece.

    Balancer / Genotype Variants of the Aberration
    Separable Components
    Other Comments

    Rare cosmopolitan inversion.

    Naturally occurring inversions have been categorised into classes according to their geographical distribution and frequencies, In(3R)C belongs to the rare Cosmopolitan class.

    Distribution in Indian populations studied.

    Rare cosmopolitan inversion. The distribution of this inversion in two populations from Valencia, Spain (one from a cellar and one from a vineyard) has been studied.

    Cosmopolitan inversion.

    Rare cosmopolitan inversion (based on Australasian frequencies of distribution).

    First inversion demonstrated genetically (Sturtevant, 1926). Used as a balancer for the region from Dl to 3R tip. Balancers contain Sb, e, l(3)a, or l(3)e. Balancer for all of chromosome 3 made by combining with In(3L)P. Found in wild populations (e.g., Oshima and Watanabe, 1965, D. I. S. 40: 88; Ashburner and Lemeunier, 1976, Proc. R. Soc. London, B 193: 137-57; Stalker, 1976, Genetics 82: 323-47; Choi, 1977, D. I. S. 52: 88; 1977, Genetica 47: 155-60).

    Synonyms and Secondary IDs (9)
    Reported As
    Name Synonyms
    Inversion (3R) Crossover suppressor
    Secondary FlyBase IDs
      References (47)