C. elegans shows ethanol-responsiveness through body-flattening. Loss-of-function mutants in the slo gene are resistant to ethanol and do not flatten their bodies. Null mutants in the npr gene show increased sensitivity to ethanol i.e. flatten their body without ethanol.
a) In the diagram, indicate whether wild-type alleles of slo and npr activate (use an arrow) or inhibit (use a T-bar) the response to ethanol.
b) What signal/ stimulus is used in optogenetics to open channel rhodopsin?
c) You test whether activation of PVM neuron can compensate for slo activity in ethanol responsiveness using channel rhodopsin (CHR) gene. Starting with a slo loss-of-function (LOF) mutant, explain how you would perform this test and what result you would expect.