Examination of mutant eyes reveal a dramatic decrease in the number of electron dense pigment granules seen surrounding groups of photoreceptor cells. Examination of retinula cells from rb1 mutants reveals normal neuronal anatomy, including normal cytoplasmic synaptic vesicles (SVs). In an assay for larval motility, or1 mutants performed as well as wild-type larvae. In locomotor assays testing olfactory response to propionic acid, or1 mutants did not perform significantly less well than wild-type larvae.
5% normal complement of drosopterin; implantation of phenylalanine crystals in pupal abdomen one day before eclosion results in bright red eye with a four-fold increase in drosopterin content.
Rank: RK1 Eye colour: bright, clear orange, growing browner as the flies age.