Consistent with single-cell RNA sequencing data and previous reporter analyses, we found that
gpla-1 is predominantly expressed in neurons associated with the gastrointestinal tract, which are part of the enteric nervous system in C. elegans. These include the pharyngeal neurons M1, M5, I5 and NSM, as well as the excitatory motor neurons AVL and DVB that control enteric muscle contractions in the hindgut during defecation. We also observed expression of
gplb-1 in the enteric DVB neuron. In addition, both
gpla-1 and
gplb-1 reporter transgenes show fluorescence in the RME motor neurons that innervate the head muscles. Using a reporter transgene for GABAergic neurons, we confirmed that
gpla-1 and
gplb-1 are both expressed in the GABAergic DVB and RME neurons. In addition, the
gplb-1 reporter transgene shows expression in non-neuronal tissues, including the head mesodermal cell (hmc) and the enteric muscles of the hindgut, which are involved in defecation. Taken together, these results indicate that expression of
gpla-1 and
gplb-1 co-localizes in the RME neurons in the head and the enteric neuron DVB in the tail, whereas no overlapping expression is seen in the pharyngeal neurons (
gpla-1) or hmc and the enteric muscles (
gplb-1).