SELF-FERTILIZATION IN TRYPANOSOMA-BRUCEI

We have investigated whether Trypanosoma brucei can undergo self-ferti lisation, A group of 27 metacyclic clones derived from the tsetse tran smission of a mixture of two genetically marked stocks was analysed an d 22 clones were observed to be of non-hybrid phenotype. A group of 10 clones from this non-hybrid subset were then analysed for one isoenzy me, one restriction fragment length polymorphism and three karyotype m arkers potentially informative for the detection of self-fertilisation . Five of the 10 clones were found to be recombinant for at least one marker and we interpret these recombination events as indicating the c lones to be products of self-fertilisation. We have also analysed a li mited number of metacyclic clones from stocks of T. brucei each singly transmitted through tsetse flies but, so far, no evidence of recombin ation has been detected. We conclude that T. brucei is able to self-fe rtilise but there may be a requirement for the presence of dissimilar stocks to initiate such an event.