Novel insertions in the mitochondrial maxicircle of , a mouse trypanosome.

is a, globally distributed, mouse-specific haemoflagellate, of the family Trypanosomatidae, which shares similar characteristics in morphology with . The kinetoplast (mitochondrial) DNA of Trypanosomatidae flagellates is comprised of catenated maxicircles and minicircles. However, genetic information on the kinetoplast remains largely unknown. In this study, the maxicircle genome was completely assembled, with PacBio and Illumina sequencing, and the size was confirmed at 34 606 bp. It consisted of 2 distinct parts: the coding region and the divergent regions (DRs, DRI and II). In comparison with other trypanosome maxicircles (, and ), the maxicircle has a syntenic distribution of genes and shares 73.9, 78.0 and 92.7% sequence identity, respectively, over the whole coding region. Moreover, novel insertions in (630 bp) and in (1278 bp) were found, respectively, which are homologous to minicircles. These findings support an evolutionary scenario similar to the one proposed for insertions in , the pathogen of American trypanosomiasis. These novel insertions, together with a deletion (281 bp) in , question the role of Complex I in . A detailed analysis of DRII indicated that it contains numerous repeat motifs and palindromes, the latter of which are highly conservative and contain AC elements. The comprehensively annotated kinetoplast maxicircle of reveals a high degree of similarity between this parasite and the maxicircle of and suggests that the DRII could be a valuable marker for distinguishing these evolutionarily related species.