rn^tot homozygosity results in loss of the olfactory receptor neuron Or67d population in the adult antenna and associated expansion of the olfactory receptor neuron Or47b population towards the toward the medial region of the antenna, as compared to controls.

rn^tot mutants exhibit Or67a-expressing olfactory receptor neuron loss in the trichoid subtype at1 sensilla. The DA1 glomerulus targeted by these receptor neurons in the antennal lobe is missing. There is an increase in the number of ORNs in the at4 sensilla.

rn^tot/rn^GAL4-5 mutants exhibit Or67a-expressing olfactory receptor neuron loss in the trichoid subtype at1 sensilla. The DA1 glomerulus targeted by these receptor neurons in the antennal lobe is missing.

rn^tod/rn^tot mutants exhibit Or67a-expressing olfactory receptor neuron loss in the trichoid subtype at1 and at3 sensilla. The DA1 glomerulus targeted by these receptor neurons in the antennal lobe is missing. There is an increase in the number of ORNs in the at4 sensilla.

rn^tod/rn^tot mutants exhibit rn-negative olfactory receptor neuron loss in the coeloconic subtype ac1 and ac4 sensilla. The ac2 sensilla expands into the antennal zones that are normally occupied by these sensilla.

rn^tod/rn^tot mutants exhibit rn-negative olfactory receptor neuron loss in the basiconic subtype ab5, ab7 and ab10 sensilla. The ab1 and ab9 sensilla show a slight increase in female mutants but not males.

Recordings of thre response of single antennal trichoid sensillae to 11-cis-vanyl-acetate (VA) indicate that tot¹ homozygotes lack T1 functional subtype of these sensillae. The overall number of trichoid and large basiconic sensillae on the antennaeCampos et al., 1985 of these flies the same as wild-type, suggesting that the missing T1 sensillae have been transformed into non-T1 trichoid sensillum types.