Figure 2: Autonomous CO2 Sensing is Required for flp-19::GFP Expression in the BAG Neurons.
From: Control of Neuropeptide Expression by Parallel Activity-dependent Pathways in Caenorhabditis elegans
(A) gcy-9(n4470) and gcy-9(tm2816) mutants exhibit reduced expression of the flp-19::GFP reporter in the BAG neurons. Micrographs show representative images of gcy-9 mutant hermaphrodites expressing the flp-19::GFP reporter (compare to Fig. 1B, top panel). BAG positions are marked with red dashed circles. Anterior to the left. Scale bar = 20 μm. (B) Quantification of flp-19::GFP expression in gcy-9(n4470) and gcy-9(tm2816) mutant animals. Transgenic expression of gcy-9 cDNA under the control of a BAG-specific gcy-33 promoter rescues gcy-9(n4470) mutant phenotype. #1-3 indicate independent transgenic rescue lines. See Materials and Methods for neuronal scoring criteria used. n > 50. ****P < 0.0001. (C) Table showing the effect of loss of O2-sensing guanylate cyclases on flp-19::GFP expression in the BAG neurons. BAG guanylate cyclase functional nulls gcy-31(ok296) and gcy-33(ok232) do not exhibit defects in expression of flp-19::GFP in the BAG neurons. Mutants for URX guanylate cyclases gcy-35(ok769) and gcy-36(db42) do not exhibit defects in expression of flp-19::GFP in the BAG neurons. The quadruple gcy-31 gcy-36; gcy-33; gcy-35 also does not exhibit any defects in BAG expression suggesting that flp-19::GFP expression in the BAG neurons is dependent on CO2 sensing and not O2 sensing.
