THE IMPORTANCE OF MOSAIC GENES TO TRYPANOSOME SURVIVAL

African trypanosomes possess several elegant ways to evade the immune defenses of mammalian hosts. They have an extensive repertoire of genes for a variant surface antigen and recent data show that this finite repertoire can be further amplified by mosaic gene formation and point mutation, producing an almost limitless capacity to vary. The significance of these mechanisms of antigenic diversity to trypanosome biology and the parasite-host relationship in general are discussed here by Anthony Barbet and Sondra Kamper.