ANALYSIS OF THE MULTIPLE PHENOTYPES OBSERVED IN PARA MUTATANTS OF DROSOPHILA

For the analysis of the functions of the para gene of Drosophila melanogaster which encodes an a subunit of the sodium channel, and of the relations to the consciousness and reflex, we utilized para^hd838 which has a P-element insertion at 279-bp upstream from the third exon, and other three alleles (para^ts1 , para^ts3 , and para^sb11 ). para^hd838 underwent paralysis at 37℃. Both para^hd838 and para^ts1 showed higher sensitivites to diethylether anesthesia than the wild type. The sodium channel(s) encoded by the pain locus may play important roles in the neuronal cells involved in the heat-induced paralysis and in the dierhylether anesthesia. Both para^hd838 and para^ts1 showed higher resistances to the knock-down responses by isonizing radiation than Canton-S. This phenotype may be related to the reduced activities of the nervous systems in para^hd838 and para^ts1 . The effects of the ionizing radiation on para^sb11 was similar to that on Canton-S. para^hd838 was normal for the olfactory response. These results indicate that the regionaround the third exon is important to the neuronal activities of the CNS and the efferent pathay, while the mutation at the 3' terminal region is not related to the activities of them but important to the afferent pathway.