In wgspd-fg mutant third instar larval wing imaginal discs, the prospective distal hinge region is reduced in size, however, there is no increase in apoptotic cells compared to wild-type.
The wing hinge region is deleted in mutant flies and the wing pouch appears directly joined to more proximal cells.
Homozygotes have shortened wings, alula etching (loss of the margin) and occasional etching of the posterior wing margin. Wings are held upward, the 'tent' phenotype. Transheterozygotes with wg alleles show an allele-dependent extent of alular etching and may show the tent phenotype. Transheterozygotes with null wg alleles only show etching of the alar lobe. Loss of Sternopleural function (by wgSp-1 or Df(2L)RF) exaggerates the etched wing phenotype of homozygotes.
wgspd-fg/wgspd-hL2 transheterozygotes exhibit complete loss of anterior and posterior wing margin structures and deletion of wing hinge structures.
Overall reduction in wing size, reduction of the alula and variable loss of posterior wing margin structures. wgl-17/wgspd-fg flies show a milder version of the hinge phenotype seen in wgspd-fg homozygotes. A deficiency that uncovers wg does not exhibit a hinge phenotype. Heterozygotes with wgspd-j2 produce a hinge phenotype indistinguishable from wgspd-fg homozygotes.
Homozygotes have small wings with severely reduced alula and defects at the wing margin. When placed in trans with lethal alleles of wg, some defects in the wing margin occur and the alula is very reduced.
Wings about two-thirds the length and three-fourths the width of wild type, held tentlike over abdomen. Alulae absent or vestigial; proximal posterior wing margins often irregular with tendency to fold under about vein L4. Venation usually normal with occasional blistering. wgspd-fg/spd has phenotype varying from slight shortening of wings to a shape midway between the two homozygotes. Excellent viability and fertility. RK1.