U.S.A. Glutamate is the major excitatory neurotransmitter in mammals and is involved in processes as diverse as cell death, and learning and memory. However, the molecular mechanisms of glutamatergic neurotransmission are yet to be elucidated. By characterizing genes encoding glutamate receptor subunits in C. elegans we hope to further our understanding of glutamate signaling. Functional NMDA receptors are composed of members from two subunit families, NR1 and NR2.
Transgenic worms show reduced locomotion and are severely touch defective.
This implies that nmr-1 expressing cells are required for normal touch responses as well as coordinated movement. To determine the function of each gene product we have generated deletion mutants. Imprecise excision of the transposable element Tc1 has deleted approximately 1.9 kb of nmr-1 genomic sequence, including that which encodes the ion channel pore of the NMDA receptor. Imprecise Tc1 excision has generated a nmr-2 deletion mutant removing approximately 2.6 kb of genomic sequence beginning proximal to transmembrane domain III and extending distal to the predicted stop codon. Characterization of these deletion mutants will allow us to determine the functional role each receptor subunit plays in distinct behaviors of C. elegans.