W57term | Pph13-PA
G to A nucleotide change at the second or third position of the Trp codon leads to a nonsense mutation (exact site of mutation unspecified). Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. Site of amino acid change reported in context of surrounding amino acids. TEARVQVWFQ changes to TEARVQV@FQ in mutant.
Newly eclosed ocuvi ; Pph13hazy double mutant adults show a complete loss of rhabdomere formation; in the majority of ommatidia there are no detectable rhabdomeres, while in a few ommatidia only rudimentary structures containing some juxtaposed membrane are seen distally.
The process of rhabdomere initiation has begun in photoreceptor cells at 60 hours after puparium formation (APF) in ocuvi ; Pph13hazy double mutants, as in wild-type photoreceptors. However, the mutant photoreceptors show clear disorganisation of the initial stages of rhabdomere elaboration. At 72 hours APF the defects in rhabdomere morphogenesis in the double mutant are more severe than in either single mutant; the apical rhabdomeric membrane lacks any definable shape and organisation in the double mutant. By 96 hours APF no rhabdomere is recognisable in the double mutants. Instead, there is a region of apical membrane that extends out into the inter-rhabdomeral space in distal portions of the retina, but this membrane lacks any organised structure. This membrane structure is visible along the entire length of the photoreceptor cell. No photoreceptor cell structures can be discerned beyond approximately 20μm from the surface of the retina, compared with 100μm for a wild-type photoreceptor cell.