Antigenic variation in Trypanosoma vivax. Isolation of a serodeme

Studies of antigenic variation inTrypanosoma vivaxhave been hindered by its low infectivity to laboratory hosts and difficulties in obtaining defined cloned populations. The recent isolation of mouse-infectiveT. vivaxhas partially overcome the first problem. We have developed a highly efficient cloning technique which has been applied to the isolation of a collection of 71 clones, representing 31 distinct variable antigen types, of mouse-infectiveT. vivaxfrom Nigeria. This serodeme showed no cross-reaction with severalT. brucei-group serodemes, but some cross-reaction with naturally occurring KenyanT. vivax.