Genes encoding glutamate receptor channel subunits were identified in genomes from Drosophila melanogaster and Caenorhabditis elegans by homology search with amino acid sequences that participate in the conserved channel pore. The predicted sequences of the putative glutamate receptor subunits revealed a distinct channel pore signature for each receptor subtype and for most of them, related members were found in C. elegans and Drosophila.