When the majority of eye cells are homozygous svspa-pol
mutant using Minute clones, the corneal lenses display slightly irregular shapes and sizes compared with wild-type eyes. The mutant lenses become progressively less defined posteriorly.
Although all cone cells and photoreceptor cells are present in most ommatidia in svspa-pol
fly eyes, they display a rough eye resulting from improperly shaped and arranged cone cells.
Mutants have cone and pigment cell defects, and photoreceptors are found in the lamina. Mutant eye discs show increased apoptosis compared to controls.
Mutant flies have a rough eye phenotype.
Flies show roughening across the entire eye.
Homozygotes show an almost complete absence of interommatidial bristles. A partial loss or misorientation of ommatidial structures is also seen.
Homozygotes have smaller eyes than normal. The corneal lenses and pseudocones are blurred and irregular. Numerous necrotic pits are seen between an irregular array of ommatidia of variable size. Nearly all bristles in the posterior of the eye have broken or fallen off by the third day after eclosion, although they are initially present when the adults eclose. Most bristles in the anterior of the eye are misplaced or project as doublets from the same vertex. Many ommatidia in adults have the normal number of photoreceptor cells, but show abnormal localisation and orientation of the photoreceptor cells and have malformed rhabdomeres. Other ommatidia have lost between 2 to 5 photoreceptor cells. Many ommatidia appear fused to each other. Cone cells retain their immature round shape and fail to adopt the typical rhomboid-like configuration 24 hours after puparium formation (APF), and some ommatidia lack one of the primary pigment cells. At 45 hours APF most ommatidia are disorganised and their regular lattice is disrupted. The cone cells are abnormal sizes and shapes and fail to form proper contacts with one another, and occasionally one cone cell is lost. Approximately half the ommatidia have lost one or two primary pigment cells, and the remaining primary pigment cell is enlarged and may enclose three of the four cone cells. There are frequently no cells remaining between primary pigment cells of adjacent ommatidia.
Eyes rather small; surface smooth and glassy. During second day of pupal life, retinula cells withdraw from other cells of eye disk. SEM studies show irregular disposition and morphology of ommatidial hairs as well as numerous necrotic pits over surface of eye (Oster and Crang, 1972); Strum-Tegethoff and Dicke, 1974). ERG absent (Grossfield, 1975). Homozygote has excellent viability and fertility. RK1.