GENETIC EXCHANGE IN TRYPANOSOMA-BRUCEI - EVIDENCE FOR MEIOSIS FROM ANALYSIS OF A CROSS BETWEEN DRUG-RESISTANT TRANSFORMANTS

Genetic exchange in Trypanosoma brucei ssp. can occur when two strains are cotransmitted through the tsetse fly vector, but it is non-obliga tory and a comparatively rare event. To increase recovery of hybrids, we crossed drug resistant parental strains and selected hybrids by dou ble drug resistance [15]. Analysis of 29 hybrid clones from five separ ate genetic exchange events shows independent segregation of marker ge nes and a high frequency of triploidy, both of which phenomena have be en observed previously for other trypanosome crosses. However, in addi tion we provide evidence of genetic recombination involving the tubuli n locus. These three observations strongly support the hypothesis that genetic exchange starts with a meiotic division in T. brucei.