Kinetoplast DNA from Trypanosoma vivax and T. congolense

We have analysed kinetoplast DNA (kDNA) of the African trypanosomes Trypanosoma vivax and T. congolense. The maxi-circles from these organisms resemble those of T. brucei in size, but only to a limited extent in sequence as judged from restriction enzyme digests and DNA X DNA hybridization. The kDNA networks of T. vivax have three distinguishing features: they contain the highest maxi-circle concentration of any kDNA (at least twice that of T. brucei); they contain the smallest mini-circles (465 bp) yet found thus far and the width of the kDNA nucleoid in thin sections is correspondingly small (55 nm against 91 nm for T. brucei); they contain a substantial fraction of mini-circle dimers.