Fig. 3. Disease-associated human Htt-polyglutamine expansion protein dynamically colocalizes with IFD-1 in touch neurons.
a–e White solid outline indicates the soma cell body and white dashed line outlines the nucleus; scale bar = 2 µm. Colocalization of N = 10 ALMs is graphed as Mander’s overlap coefficient of mScarlet channel over mNeonGreen channel, with boxes indicating the coefficient range. a Representative adult touch neuron expressing single copy bzSi38[Pmec-7mNG::UBQ-2]; bzSi34[Pmec-7mSc::IFD-1]; range minimum (0.65), maximum (0.94), and mean (0.79) coefficient. b Representative adult touch neuron expressing bzEx422[Pmec-7mNG::UBQ-2]; bzEx421[Pmec-7mSc::IFD-2]; range minimum (0.20), maximum (0.98), and mean (0.66) coefficient. c Representative adult touch neuron expressing bzSi39[Pmec-7HttQ74::mNG]; bzSi34[Pmec-7mSc::IFD-1]; range minimum (0.26), maximum (0.85), and mean (0.59) coefficient. Images selected were those in which mNG was visibly aggregated in the cell, as opposed to homogeneous dim cytosolic signal. d Representative adult touch neuron expressing bzSi40[Pmec-7mNG::HttQ74]; bzEx420[Pmec-7mSc::IFD-2] that displays visible mNG aggregation; range minimum (0.15), maximum (0.72), and mean (0.57) coefficient. e Representative adult touch neuron expressing igIs1[Pmec-7YFP Pmec-3HttQ128::CFP]; bzSi34[Pmec-7mSc::IFD-1] that displays visible CFP and mSc co-expression; range minimum (0.43), maximum (0.99), and mean (0.56) coefficient. f HttQ128::CFP is expressed from a high-copy-number integrated transgene array. The IFD compartment often does not appear to fully surround the HttQ128 signal. Top row: Adult touch neuron soma displaying the three main patterns of interaction we note in lines that express mScarlet::IFD-1 and HttQ128::CFP. (1) HttQ128 and IFD overlap entirely (white arrows). (2) HttQ128 and IFD display a bi-lobed globular interaction, where part of the bi-lobed structure has overlap of HttQ128 and IFD. (3) HttQ128::CFP signal fully encompasses the IFD signal. Bottom row: side view z-stack (0.2 µm) from the image in the top row.
