Abstract 94-10929 Studies of the NOD kinesin-like protein found in Drosophila melanogaster and its role in mediating achiasmate disjunction will be continued. These studies are designed to test a model in which the NOD kinesin-like protein is distributed along the length of the chromosome arms and acts to push chromosomes away from the poles. We also propose to continue our molecular and genetic studies of the Axs gene and its role in allowing the proper separation of achiasmate homologs. In the absence of normal Axs gene product, achiasmate homologs fail to separate and cause the developing spindle to buckle, fray or even break. Thus, a detailed understanding of the Axs gene product will provide significant insight into the manner by which achiasmate homologs are associated prior to their separation. Finally, a screen designed to identify mutations specifically defective in heterologous segregation will be carried out. The subsequent molecular analysis of genes defined by these mutations represents a long term goal of this proposal. %%% How chromosomes identify their partners and thereby allow the orderly process of transmission of the correct number and types of chromosomes to progeny is a central question in heredity. Work from this laboratory has contributed much to our understanding of some of the involved mechanisms. Genetic approaches have been used to demonstrate that, in Drosophila females at least, there are two separate systems of achiasmate segregation. The elucidation of the physical bases of these processes at the molecular level is the goal of this work. ***
