Abstract
Sixteen non-fusing mutants (γ) were isolated from virus (G) possessing fusion ability. Some mutant pairs complemented each other which resulted in an extensive cell fusion as original G virus, while the other mutant pairs did not. Thus, these mutants were classified into four complementation groups. By recombination analysis using eight γ mutants belonging to each complementation group, a linkage map has been constructed with regard to cell fusion. It has been demonstrated that four or possibly six cistrons are associated with the fusion event.
