Figure 6.

d-plp²¹⁷² mutants have defects in mechanosensory neuron function. (A) A trace of the SEPs originating from the auditory chordotonal organ of a d-plp ²¹⁷² homozygous and a d-plp ²¹⁷² heterozygous adult. (B) The distribution of the peak SEP amplitudes in d-plp ²¹⁷² homozygotes (red) and d-plp ²¹⁷² heterozygotes (black). (C–H) Micrographs show the chordotonal neurons in the second and third antennal segments of WT flies (C–E) or d-plp ²¹⁷² homozygous mutant flies (F–H). The neurons express the mCD8-GFP membrane marker (left panel; green in image merged with a DIC view); a magnified view or the second segment is shown in E and H. In d-plp ²¹⁷² heterozygous antennae, the extended outer segment cilia of the mechanosensory chordotonal neurons in the second antennal segment (arrows) and the chemosensory neurons in the third antennal segment (arrowheads) are clearly visible. In d-plp ²¹⁷² homozygous mutant antennae, most of these extended cilia are either absent or short and kinked, and the chordotonal cilia of the second segment fail to attach to the cuticle that connects the second and third antennal segments (asterisk). Bars, 20 μm.