A NOVEL INVERTEBRATE GABA(A) RECEPTOR-LIKE POLYPEPTIDE - SEQUENCE ANDPATTERN OF GENE-EXPRESSION

A full-length complementary DNA has been isolated, from the fresh-wate r mollusc Lymnaea stagnalis, that encodes a polypeptide (which we have , named zeta) that exhibits between 30% and 40% identity to vertebrate GABA(A) and glycine receptor subunit sequences. The locations of seve n introns have been determined in the corresponding gene and six of th ese occur at similar relative positions as those found in vertebrate G ABA(A) receptor genes. RNase protection studies have revealed that the transcript for this Lymnaean polypeptide is present at highest levels in the adult nervous system but that it can also be detected in perip heral tissues.