In amos1/Df(2L)M36F-S6 adult flies, the anterior part of the antennal lobe is disrupted and glomerular borders are fuzzy, while the posterior side seems to be unaffected. ato-positive olfactory receptor neurons Ir92a and Ir75a are unaffected, with axonal projections similar to wild-type controls.
The number of neurons in the dorsal organ ganglion are reduced in mutant embryos compared to wild type. The number of olfactory receptor neurons in the DO ganglion is reduced in the mutant embryos (average number is 12 compared to the wild-type number of 21).
Mutant embryos lack two dorsal sensory neurons per segment, including the dorsal bipolar dendritic neuron. Adults are viable as homozygotes and hemizygotes. In amos1/Df(2L)M36F-S6 animals the third segment of the antenna is reduced because of missing basiconica and trichodea. In the pupal antennal imaginal disc of mutant animals, the first and second waves of sensory organ precursor formation appear to occur normally, but the third phase fails to occur.