Open Close
General Information
Symbol
In(1)wm4
Species
D. melanogaster
Name
Inversion (1) white-mottled
FlyBase ID
FBab0004257
Feature type
Also Known As
wm4, wm4e
Computed Breakpoints include
3C2;h28
Sequence coordinates
X:2,766,979..2,768,245 (In(1)w[m4]:bk1)
Member of large scale dataset(s)
Nature of Aberration
Cytological Order
Progenitor
Mutagen
Class of aberration (relative to wild type)
Causes alleles
Carries alleles
Transposon Insertions
Formalized genetic data
l(1)2Ea << bk1 << w << CR << bk2
Genetic mapping information
Comments
Breakpoint reported to map between R5 cordinates X:2661012 and X:2662278 .
Breakpoint(s) molecularly mapped
Left (3C1-2) breakpoint at -24.5 kb in the restriction map of the w locus (0 point at site of the copia insertion in wa); right (20F) breakpoint near 5' end of a Type I mobile element (Tartof et al., 1984). Left breakpoint less than 3kb distal to the w-a copia insertion (Pirrotta et al., 1983).
Comments on Cytology
Distal inversion breakpoint is ~20kb from the 3' end of the w locus, the proximal inversion breakpoint is within centric heterochromatin distal to bb. Heterochromatic breakpoint is flanked by a Type I mobile element (FBrf0040503).
Proximal breakpoint defines the distal boundary of the bb locus.
Proximal breakpoint is approximate. The distal breakpoint is to the left of w and the proximal breakpoint is to the left of bb.
Limits of break 1 from polytene analysis (FBrf0018623) Limits of break 2 from polytene analysis (FBrf0040503)
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
 
Phenotypic Data
In combination with other aberrations
The X heterochromatin in Dp(1)A140 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The X heterochromatin in Dp(1;f)1173 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The X heterochromatin in Dp(1;f)1187 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The X heterochromatin in Dp(1;f)1205 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The X heterochromatin in Dp(1;f)1346 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The autosomal heterochromatin in Dp(2;f)e51 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The autosomal heterochromatin in Dp(2;f)e58 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The autosomal heterochromatin in Dp(2;f)e97 appears to suppress the eye colour variegation phenotype of In(1)wm4.
The position effect variegation (PEV) at the w locus seen in the In(1)wm4 chromosome is suppressed if males are also carrying one of Df(Y)bb-465, Df(Y)bb-76, Df(Y)l-481, Df(Y)l-498, Df(Y)l-510 or Df(Y)l-473.
Df(3L)Aprt-21 dominantly enhances the position effect variegation of the w gene caused by In(1)wm4.
The position effect variegation of the w gene seen in In(1)wm4 flies is partially suppressed by one copy of Df(2L)DS5 or Df(2L)DS6.
The position effect variegation of w seen in In(1)wm4 is suppressed by one copy of Df(3R)crb-F89-4.
Position effect variegation (PEV) at the w locus caused by In(1)wm4 is dominantly enhanced by Dp(2;2)Mdh and suppressed by Df(2R)en-A or Df(2R)en-SFX31.
The position effect variegation at the w locus caused by In(1)wm4 is suppressed by Df(3R)Ace-HD1.
The position effect variegation of w caused by In(1)wm4 is enhanced by Df(2L)cl-h1 and Df(2L)cl-h4. This phenotype is suppressed by Hel25E+t4.5; the level of variegation seen in In(1)wm4 ; Df(2L)cl-h4/Hel25E+t4.5 flies is the same as seen in In(1)wm4/+ flies.
The position effect variegation of Sb caused by T(2;3)SbV is suppressed by In(1)wm4. The T(2;3)SbV chromosome may have a slight suppressing effect on the variegation of w caused by In(1)wm4 in males.
NOT in combination with other aberrations
A notable enhancement of position effect variegation in observed in the presence of B chromosomes, small, heterochromatic chromosomes that are transmitted in a non-Mendelian manner.
In(1)wm4 silences w expression in most cells of the eye, leading to a variegated eye colour much lighter than normal.
Tn10\tetRey.3.5.T:Hsim\VP16-mediated expression of Hsap\HMGA1MATH20.tetO in In(1)wm4 flies results in significant derepression of the w gene and a general loss of the variegating phenotype. Tetracycline treatment inhibits Hsap\HMGA1MATH20.tetO-induced suppression of PEV. Tn10\tetRey.3.5.T:Hsim\VP16-mediated expression of Hsap\HMGA1MATH11.tetO in In(1)wm4 flies results in no significant derepression of the w gene, no loss of the variegating phenotype.
The position effect variegation at the w locus caused by In(1)wm4 is enhanced by Su(var)3-7+t6.5.
HDAC115-1 enhances the variegation of w in In(1)wm4 flies and in 5-10% of the eyes patches of ommatidia show disorganisation characteristic of the rst mutation (enhancement of variegation allows the silencing to spread past the w locus to inactivate rst in a fraction of the cells).
Variegated eye phenotype is enhanced in the presence of mod(mdg4)ul, mod(mdg4)u2 and mod(mdg4)B2, eyes appear yellow with orange spots. In the presence of su(Hw)MC the phenotype is no longer enhanced and the eye phenotype returns to wild type. These results indicate that the variegating phenotype is caused by the su(Hw) protein.
z+ In(1)wm4 flies reared at 25oC have dark red/brown mottled eyes. z1 In(1)wm4 males and females have fewer red/brown patches on a lighter background, paired copies of In(1)wm4 are not repressed to z eye colour (lemon yellow). Repression of In(1)wm4 by z1 cannot be restored by Su(var)205. zv77h In(1)wm4 females and males have almost bleached white eye colour with a few scattered red facets, Su(var)205 only moderately suppresses PEV.
Wowγb, Wowγe and Wowhd1 act as suppressors of variegation of w in In(1)wm4.
The position effect variegation caused by In(1)wm4 is dominantly suppressed by Su(z)121.
Carnitine compounds (L-Carnitine, L-Acetylcarnitine and L-Propionylcarnitine) show a significant suppression on w variegation. Butyrate gives a weaker suppression. In males the suppression effect of the compounds was seen at all concentrations, but in females the effect is weak and is only seen with high concentrations.
In(1)wm4 flies show position effect variegation at the w locus, at 23oC the phenotype varies from a sectored red and white eye to a red eye peppered with small flecks of red and brown pigmented ommatidia.
Eyes have a "sectored" phenotype - ommatidia are either fully pigmented or not pigmented at all.
Enhances the expression of PgdA in larvae and adults.
Males and homozygous females are viable and fertile.
Stocks (21)
Notes on Origin
Discoverer
Muller, 1929.
 
Balancer / Genotype Variants of the Aberration
 
Separable Components
 
Other Comments
 
The presence of a variegating chromosome and a modifier chromosome in the same parental genome can alter the amount the amount of variegation formed in the progeny. The genomic imprinting is not determined by the parental origin of the variegating chromosome but is instead determined by the genetic background the variegating chromosome is subjected to during gametogenesis.
w transvection is eliminated by PEV.
X ray-induced revertants of In(1)wm4 may or may not carry a segment of flanking heterochromatin: variegation is not controlled from immediately adjacent heterochromatic sequences at the euchromatin/ heterochromatin border but from a site more internal to the heterochromatin domain.
A strongly variegating line has been designated In(1)wm4h.
Synonyms and Secondary IDs (15)
Reported As
Symbol Synonym
In(1)w-m4
In(1)whitem4
In(1)y1wm4
Name Synonyms
Inversion (1) white-mottled
white mottled 4
whitemottled4
Secondary FlyBase IDs
  • FBal0018268
References (178)