Fig. 2. GLR-2 tail sequences are required for heteromeric receptor synaptic localization and stability. (Top) The sequences of GLR-2 included in the GLR-2::YFP and GLR-2(tailless)::GFP transgenes. The arrowhead indicates the position of the fluorescent tag (between a.a. 946-947 for full-length, and after the final transmembrane domain for the tailless form) used to monitor the protein. (A,C) GLR-2(tailless)::GFP expressed in wild-type, and glr-1 and glr-2 double deletion, respectively. (B,D) Full-length GLR-2::YFP expressed in wild-type, and glr-1 and glr-2 double deletion, respectively. (A) GLR-2(tailless)::GFP can exit the neuron cell body and populate the synapses of the nerve ring (bracket) and proximal dendrites (arrows) as long as there is endogenous full-length receptor present. (B) However, GLR-2(tailless)::GFP remains in the cell body (arrowhead) when there are no endogenous subunits present. All the images were captured using either YFP or FITC filters, and were taken from the head region of the animal (anterior oriented diagonally down and to the left, dorsal up and to the left). The image in C was taken at a higher exposure to reveal the faint GFP fluorescence of the cell body; consequently, the background autofluorescence from the underlying pharyngeal tissue is also revealed. The neuron shown in all four panels is AVD. Bars, 10 µm.