ANALYSIS OF SEQUENCES OF 2 DIFFERENT CLASSES OF KINETOPLAST DNA MINICIRCLES OF A LEISHMANIA SPP

We have determined the nucleotide sequences of the minicircles represe nting a major (pLURkE3) and a minor (pLURkH13) class populations from the kinetoplast DNA of Leishmania strain UR6. These minicircles have s equence organization similar to other kinetoplastid parasites, however , they have some unique structural features. These features include th e following: (i) imperfect inverted repeat in the variable regions, si milar to the conserved sequence elements of guide RNA genes in African trypanosomes, (ii) tandem and non-tandem direct repeats of 8 bp or lo nger scattered throughout the minicircles, (iii) non uniform strand di stribution of bases throughout the minicircles and (iv) high TG conten t, more than half of the molecules being extremely (T + G) versus (A C) strand biased. The heterogeneity of minicircle sequences in the va riable regions may be exploited in developing recombinant DNA based di agnostic probes for detection and classification of Leishmania species .