Figure 6. The whole-cell Cl^- current recording of ADGRG2 promoter-labeled efferent ductule cells.

(A) Time course of whole-cell Cl^- current (I_ADGRG2-ED) at +100 and −100 mV in ADGRG2 promoter-labeled efferent ductule cells derived from Adgrg2^-/Y mice or their littermates. An ‘a’ or ‘d’ indicates the substitution of the Cl^- bath solution with Gluc^- (148.5 mM Cl^- was replaced by 48.5 mM Cl^- and 100 mM Gluc^-); and ‘b’ or ‘e’ indicates the substitution of the Gluc^- bath solution with Cl^- (148.5 mM Cl^-). ‘a’,”b’ and ‘c’ belong to WT mice. ‘d’,”e’ and ‘f’ belong to Adgrg2^-/Y mice. (B) The current-voltage relationship of I_ADGRG2-ED at specific time points (from 6A) is shown. (C) The whole cell Cl^- current of I_ADGRG2-ED elicited by voltage steps between −100 mV and +100 mV in a representative ADGRG2-promoter-RFP labeled efferent ductule cells derived from the Adgrg2^-/Y mice and their wild type littermates. The outwardly rectifying I_ADGRG2-ED was significantly diminished when bath Cl^- was substituted for gluconate (Gluc^-). (D) Representative whole-cell Cl^- current of ADGRG2 promoter-labeled efferent ductule cells; I_ADGRG2-ED versus voltage (I–V) relationships in response to voltage ramps recorded with a CsCl pipette solution in Adgrg2^-/Y (n = 8) or WT mice (n = 8). The outwardly rectifying I_ADGRG2-ED was significantly diminished, and its reversal potential (E_rev) shifted to the positive direction when Cl^- was substituted for Gluc^-. (E) Average current densities (pA/pF) measured at 100 mV of (C). Inset: average Erev (±s.e.m., n = 8 for each condition). **p<0.01, I_ADGRG2-ED in Gluc^- solution was compared with I_ADGRG2-ED in Cl^- solution. ns, no significant difference. At least three independent biological replicates were performed.