Heterozygotes have a mirror image homeotic transformation of anterior wing to posterior wing. All anterior wing blade structures are replaced with a mirror image of the posterior structures. No transformation of the wing hinge, notum or pleural thoracic tissue is seen. The transformation phenotype is weakest at lower temperatures. invW/invunspecified flies have a similar phenotype to invW/+ heterozygotes, although the wing veins adjacent to the anterior/posterior compartment border are often incomplete at the distal tip of the wing.
Anterior to posterior cell fate transformation in the wing, veins 1 and 2 are replaced by 4 and 5 with the associated crossvein.
One dose removes entire wing margin.
homozygous lethal; dominant with homeotic effect; vgW/+ is wingless or has tiny buds, no halteres (or one); female fertile and viable
Df(2R)en-SFX31, invW has visible | dominant phenotype
Wing vein formation is suppressed in invW ph-d209 double heterozygotes both within the normal and transformed portions of the wing. invW/Df(2R)en-SFX31 flies show the transformation of anterior compartment to posterior compartment and disorganisation of wing veins. Wings are held out and down.
Shukla.
The invW homeotic wing phenotype is difficult to study using this chromosome because In(2R)vgW also causes a dominant vgW allele which produces a loss of wing phenotype. γ ray mutagenesis of the In(2R)vgW chromosome resulted in a deletion which altered the vgW mutation to a recessive vg allele (vgWR2). This allows the dominant invW phenotype to be studied.
It is difficult to determine inv activity in In(2R)vgW, but the possibility that invW has a neomorphic contribution to the vgW phenotype cannot be eliminated.
inv is expressed in a vg-like pattern.