Fig. 4.

Protocol used to identify cell fusion genes. The four steps in the protocol used to identify genes required for cell fusion are shown. The first step involved screening each of the 10,000 mutants in the single gene deletion library to identify those with a cell fusion phenotype. The second step involved mating each of the putative mutants with a wild-type isolate to demonstrate that the mutant phenotype cosegregated with the deletion mutation. The third step involved assessing whether the mutants were able to generate CATs. In the final step, complementation experiments were carried out to demonstrate that the deletion mutation was responsible for the mutant phenotype.