CHARACTERIZATION OF KINETOPLAST DNA FROM PHYTOMONAS-SERPENS

The restriction enzyme digestion of kinetoplast DNA from four Phytomon as serpens isolates shows an overall similar band pattern. One minicir cle from isolate 30T was cloned and sequenced, showing low levels of h omology but the same general features and organization as described fo r minicircles of other trypanosomatids. Extensive regions of the minic ircle are composed by G and T on the H strand. These regions are very repetitive and similar to regions in a minicircle of Crithidia oncopel ti and to telomeric sequences of Saccharomyces cerevisiae. Conserved S equence Block 3, present in all trypanosomatids, is one nucleotide dif ferent from the consensus in P. serpens and provides a basis to differ entiate P. serpens from other trypanosomatids. Electron microscopy of kinetoplast DNA evidenced a network with organization similar to other trypanosomatids and the measurement of minicircles confirmed the size of about 1.45 kb of the sequenced minicircle.