GENETIC-STUDIES ON DYNAMIN FUNCTION IN DROSOPHILA

The shibire(ts2) mutation of Drosophila melanogaster causes a temperat ure sensitive inhibition of endocytosis; this in turn leads to synapti c-vesicle depletion and consequent paralysis. Heat-pulses delivered du ring development of shibire(ts2) individuals affect the morphology of a number of adult structures. A simple screening protocol has been use d to isolate several mutations that partially suppress the temperature -sensitive paralytic phenotype of shibire(ts2) mutant animals. All of these mutations very tightly linked to shibire and are likely to be se cond site intragenic mutations that restore partial activity to the sh ibire(ts2) product. The mutations suppress both behavioral, and easily -scored developmental phenotypes of shibire(ts2) characterized in this paper. Our results Suggest that defects in endocytosis, and not in mi crotubule interactions, are responsible for all of the phenotypes of s hibire(ts2) mutant Drosophila examined in this study.