The genes for variant antigens in trypanosomes.

We have studied the mechanism of antigenic variation by using DNA complementary to the messenger RNAs for four variant surface glycoproteins of Trypanosoma brucei. Pure complementary DNAs were obtained by cloning as recombinant DNA in Escherichia coli. Using these complementary DNAs as hybridization probes, we have analyzed the genes for these variant surface glycoproteins. The results provide new information on the origin and evolution of antigenic variation, and on the mechanism involved in switching from one antigenic type to another.