Both Pcho-1::GFP fusions are strongly expressed in the nervous system. However, there were some differences between the two reporters; the 7.6-kb reporter was expressed in several head neurons that did not express the 5.2-kb reporter. The 7.6-kb reporter was expressed in most cholinergic neurons, as well as some non-neuronal cells, including the posterior-most three or four intestinal cells. The
cho-1 reporter was not expressed in all cholinergic neurons, however, at least three cholinergic neurons in the head lacked detectable expression. In addition, the
cho-1 reporter was expressed in several additional (presumably non-cholinergic) neurons in the head and tail. Thus, expression of the CHO-1 transporter is largely, but not exclusively associated with cholinergic neurons.