3E-03 THE ROLE OF CYCLIC-NUCLEOTIDE SIGNALING PATHWAY IN THE MECHANISM OF CULTIVATION TEMPERATURE AVOIDANCE IN C.ELEGANS

It is known that cyclic-nucleotides play an important role in the mechanism of learning and memory. To investigate the role of cyclic-nucleotide in the mechanism of learning and memory in C. elegans, we assayed starvation-induced cultivation temperature avoidance for pde-5(nj49), egl-4(n479) and acy-1(nu329), which are defective in a signal ing pathway mediated by cyclic-nucleotide. pde-5, egl-4 and acy-1 genes encode C. elegans homologue of phosphodiesterase 10 (PDE10) that is known as cAMP-inhibited cGMP PDE, cGMP-dependent protein kinase (PKG) and adenylyl cyclase, respectively. As a result, pde-5(nj49) showed weak Aho phenotype after they were grown at 17℃ or at 25℃. egl-4(n479) showed remarkable Aho phenotype when they were grown only at 25℃, however, egl-4 showed almost normal cultivation temperature avoidance after they were grown at 17℃. acy-1(nu329) showed almost normal cultivation temperature avoidance after they were grown at 17℃ or at 25℃. These results suggest that PDE-5, homologue of PDE10, and EGL-4, PKG, are essential for mechanism of cultivation temperature avoidance, and that cGMP is important in this mechanism. Now, we are trying to isolate other pde mutants, pde-1, -2, -3, -4 and -6. In the future, to further elucidate the role of cyclic-nucleotide in cultivation temperature avoidance, we will assay cultivation temperature avoidance and other behavioral phenotypes of pde mutants, egl-4(n479) and acy-1(nu329).