Homozygotes show abnormal trap-entry with food medium or ethyl acetate as the stimulus, and a normal response to ethyl acetate, propionic acid or benzaldehyde in a chemosensory jump assay. ERG is normal. Giant fibre pathway physiology appears normals.
Abnormal trap-entry kinetics (cf. ota1), with food medium or ethyl acetate as stimulant (isolated using former). In odor induced jump tests ota21 responded normally to ethyl acetate, propionic acid and benzaldehyde. ERG normal