Sá-Carvalho D, Perez-Morga D, Traub-Cseko Y M
Departamento de Bioquímica e Biologia Molecular, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
J Eukaryot Microbiol. 1993 May-Jun;40(3):317-22. doi: 10.1111/j.1550-7408.1993.tb04922.x.
The restriction enzyme digestion of kinetoplast DNA from four Phytomonas serpens isolates shows an overall similar band pattern. One minicircle from isolate 30T was cloned and sequenced, showing low levels of homology but the same general features and organization as described for minicircles of other trypanosomatids. Extensive regions of the minicircle are composed by G and T on the H strand. These regions are very repetitive and similar to regions in a minicircle of Crithidia oncopelti and to telomeric sequences of Saccharomyces cerevisiae. Conserved Sequence Block 3, present in all trypanosomatids, is one nucleotide different from the consensus in P. serpens and provides a basis to differentiate 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.
对来自四种蛇形植鞭毛虫分离株的动基体DNA进行限制性酶切消化，结果显示出总体相似的条带模式。对分离株30T的一个微小环进行了克隆和测序，结果表明其同源性较低，但具有与其他锥虫微小环所描述的相同的一般特征和结构。微小环的广泛区域在重链上由G和T组成。这些区域具有高度重复性，并且与克氏锥虫微小环中的区域以及酿酒酵母的端粒序列相似。在所有锥虫中都存在的保守序列块3，在蛇形植鞭毛虫中与共有序列有一个核苷酸的差异，这为区分蛇形植鞭毛虫与其他锥虫提供了依据。动基体DNA的电子显微镜观察显示出一个结构类似于其他锥虫的网络，对微小环的测量证实了已测序微小环的大小约为1.45 kb。
