Lina Ni, Mason Klein, Kathryn Svec, Gonzalo Budelli, Elaine C Chang, Richard Benton, Aravi DT Samuel, Paul A Garrity
Nice work!-very cool to expand the role of IRs in biology.
in the manuscript not by urgency/priority
L139 what is the evidence that IR21a is endogenously expressed in
DOCCs? Anything beyond the Gal4 line? Antibody/in situ? My former PhD student Kenta
Asahina was the king of larval in situs, but that was done before the IRs were
L166 did you do a rescue of Ir25a just in the Ir21a DOCCs? Ir25a is
*everywhere* which is a problem for claiming specificity
L192 I don’t understand how brv1 is showing such a clear phenotype, and
not necessary for DOCC responses. Must be some other cells elsewhere that
L195 I thought the conclusion here was overly strong given the strength
of the evidence offered
L226 This is a great experiment—very elegant
L216 wondered why you did pan-neuronal Ir21a expression rather than
just go with the much more selective HC>Ir21a. You could consider showing
the HC result in the main figure, and putting the pan-neuronal as data not
shown. Always makes me nervous to put a protein like that into *all neurons*
L246-253 could equally be a cell biological problem with trafficking
unrelated to any functionally relevant co-factor. I would not be so forthright
here (unless you have the answer in the form of the co-factor in hand already)
L257-259 I agree with this conclusion. I think Ir25a is receptor for
heat just as much as orco is a sensor for ethyl acetate. It’s the wrong way to
look at this. Of course a ‘co-receptor’ will have a selective phenotype, but
it’s wrong to conclude that it is the subunit responsible for the specific
Figure 1 I don’t understand why you are doing huge temperature swings
of 14oc vs 20oc. You say these neurons are extremely sensitive to small changes
in temperature, why not image under those conditions. Also you have the chance
to analyze the kinetics of the response to extract party of the answer. Since
your temperature ramps are slow, you could calculate the onset of calcium
signal and the rise time, etc.
Figure 2b I found the cartoon very busy and confusing. All I cared
about was what the temperatures at the extremities were and that was not
Figure 2c what is navigational bias, not defined?
Figure 2c are the Ir21 mutants actually PREFERRING the cold?
Figure 2 general: it looks like you are not doing single animal
tracking here. Can you revise the data presentation to extract additional
information on speed, turning, path tortuosity, etc etc rather than just a
single index number.
Figure 3 very pretty! But could integrate into another figure because
it’s making a single elegant point, while the other figures are pretty crowded.
Figures 4-5 my lab had the hardest time with this experiment. We
understand what you are trying to do here, but it’s not easy to explain or
understand. Isn’t IR21a already expressed in these cells? What happens if you
overexpress Ir25a? or Ir8a? Or some other random protein? I worry that the
small bumps in Figure 5d are some nonspecific problem with the neuron. Can’t
exclude that with the current data? It looks like there is still some low
amplitude cycling in Ir21a mutants? (Figure 4d, f). Do you think that’s real?