Figure 1
From: Deciphering and modulating G protein signalling in C. elegans using the DREADD technology
The mammalian rM3Dq DREADD and rM3R are not functional in spicule protraction, as a model for DREADD activation in C. elegans.
(A–D) Schematic representation of spicule protraction and theoretical model of GAR-3 and DREADD activation in this context, that all DREADD characterisations are based on (see Figs 1E and 4F). (A) GAR-3 mediates a Gq-protein signal which is involved in spicule protraction of the male nematode during mating culminating in insertion of the spicule into the hermaphrodite’s vulva. (B) GAR-3 can be activated by Oxo M and CCh to induce spicule protraction involving the Gq protein-signalling cascade. This effect is independent of the presence of a hermaphrodite. (C) In the absence of GAR-3 neither Oxo M nor CCh trigger spicule protraction. (D) DREADDs activating the Gq protein-signalling cascade specifically trigger spicule protraction upon stimulation with CNO, but not with Oxo M or CCh. Such DREADDs can be rM3Dq or a C. elegans-specific DREADD (cegar-3Dq) in gar-3-deficient males. (E) Protraction rate in male nematodes containing mammalian DREADD constructs. Males were incubated with 100 mM Oxo M, 10 mM CCh, 2 mM CNO or H2O as negative control. Subsequently, spicule protraction was scored and protraction rates calculated in respect to the total male count. Wild-type worms (pha-1(e2123); him-5 (e1490)), gar-3 (pha-1(e2123); him-5 (e1490) gar-3(gk305)) and transgenic gar-3; Ex[gar-3(+)] males served as controls. Data are shown as mean ± SD. ***p < 0.001; n ≥ 250. Indicated below each set of columns is the schematic model related to the respective data.
