Wu 9420625 The genetic basis of hybrid sterility between Drosophila simulans and Drosophila mauritiana has been shown by this laboratory to be clusters of strongly interacting loci which jointly lead to male sterility. One of the clusters is between the f and Bx marker, occupying about 5% of the X chromosome. The objective of this proposal is to clone and characterize a hybrid sterility gene, Ods, which is an important component of that cluster. After cloning and characterizing the gene, it will be used to test the various evolutionary hypotheses at the molecular level. Specifically, we will test for the most significant feature of Haldane's rule, the very rapid evolution of hybrid male sterility. %%% The genetic basis of speciation and species differences is undoubtedly one of the central questions in evolutionary biology. It is crucial to clone and characterize a gene which can be identified as having a role in functional divergence between species in order to understand the molecular basis of speciation. Such a cloned gene will make it possible to experimentally test the various contending evolutionary hypotheses at the molecular level. ***
