Abstract
Three distinct Chinese hamster ovary mutants selected for resistance to wheat germ agglutinin were previously described by this laboratory. In this paper, evidence is provided that each phenotype occurs at a similar frequency in an unmutagenized population of Chinese hamster ovary cells. Two novel wheat germ agglutinin resistance phenotypes (WgaR), which also appear to occur at similar frequencies were uncovered in the course of these studies. One mutant type belongs to a new, recessive complementation group (VIII), and the second belongs to a previously defined complementation group (VI). Mutants from each of the four WgaR complementation groups (I, II, III, and VIII) exhibited characteristic and unique patterns of resistance to the toxicity of a variety of plant lectins. These properties were used in developing independent selection protocols which were highly specific for the isolation of each of the mutant types.