4bp deletion immediately downstream of the signal-peptide sequence in Osi23.
4bp deletion in Osi23 leads to a frameshift at amino acid 29 and early translation termination after the addition of five novel amino acids.
Osi231 homozygotes show no visible defect in adult external morphology; the maxillary palp olfactory sensilla have significantly fewer nanopores, which is associated with severely reduced electrophysiological responses to both strong and weak odor stimuli, as compared to controls. In agreement, pupal maxillary palp olfactory sensilla show a flat cuticular envelope lacking pores, instead of the curved cuticular envelope with pores observed in controls.
Osi231 is partially rescued by Osi23Tag:HA