Edinburgh Napier University

  We report the isolation of molluscan (Lymnaea stagnalis) partial complementary DNAs (cDNAs) that encode two new putative glutamate-gated cation-channel polypeptides. These proteins, which we have named Lym-eGluR4 and Lym-eGluR5, exhibit 56% identity to each other, and strong similarity (56% to 61%, and 56% to 68% identity, respectively) to the corresponding portions of vertebrate and invertebrate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-selective (or AMPA-like) glutamate receptor (GluR) subunits. Using in situ hybridisation, we have shown that the Lym-eGluR4 and Lym-eGluR5 genes are both transcribed in all 11 central ganglia of the molluscan nervous system; however, their patterns of expression are quite different. Interestingly, the Lym-eGluR5 mRNA is present in an identifiable neuron (RPeD1), within the right pedal ganglion, that has recently been shown to possess a GluR that can be readily activated by L-glutamate, quisqualic acid and kainic acid. © 1997 John Wiley & Sons, Ltd.