Guangdong Provincial Key Laboratory of Aquatic Economic Animals, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, The People's Republic of China.
Ecosystems and Environment Research Centre and Biomedical Research Centre, School of Science, Engineering and Environment, University of Salford, Salford M5 4WT, UK.
Parasitology. 2022 Oct;149(12):1546-1555. doi: 10.1017/S0031182022001019. Epub 2022 Aug 4.
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.
是一种全球性分布的、专性寄生在鼠类的血鞭毛原生动物，属于动基体目（Trypanosomatidae），其形态与 相似。动基体目鞭毛原生动物的动基体（线粒体）DNA 由连环的大环线和小环线组成。然而， 动基体的遗传信息在很大程度上仍然未知。在本研究中，使用 PacBio 和 Illumina 测序技术，完全组装了 的大环线基因组，大小确认为 34606bp。它由 2 个不同的部分组成：编码区和发散区（DRs，DRI 和 II）。与其他锥虫的大环线（ 、 和 ）相比， 的大环线具有基因的同线性分布，并在整个编码区分别共享 73.9%、78.0%和 92.7%的序列同一性。此外，在 （630bp）和 （1278bp）中分别发现了新的插入序列，它们与小环线同源。这些发现支持了一种与美洲锥虫病病原体 中插入序列类似的进化情景。这些新的插入序列，以及 中的缺失（281bp），质疑了 Complex I 在 中的作用。对 DRII 的详细分析表明，它包含许多重复基序和回文序列，后者高度保守，包含 AC 元件。 的动基体大环线的全面注释揭示了这种寄生虫与 的大环线之间高度的相似性，并表明 DRII 可能是区分这些进化相关物种的有价值的标记。
