Schaer Juliane, Reeder DeeAnn M, Vodzak Megan E, Olival Kevin J, Weber Natalie, Mayer Frieder, Matuschewski Kai, Perkins Susan L
Max Planck Institute for Infection Biology, Parasitology Unit, 10117 Berlin, Germany; Museum für Naturkunde - Leibniz Institute for Research on Evolution and Biodiversity, 10115 Berlin, Germany.
Department of Biology, Bucknell University, Lewisburg, PA 17837, USA.
Int J Parasitol. 2015 May;45(6):375-84. doi: 10.1016/j.ijpara.2015.01.008. Epub 2015 Mar 9.
Parasitic protozoan parasites have evolved many co-evolutionary paths towards stable transmission to their host population. Plasmodium spp., the causative agents of malaria, and related haemosporidian parasites are dipteran-borne eukaryotic pathogens that actively invade and use vertebrate erythrocytes for gametogenesis and asexual development, often resulting in substantial morbidity and mortality of the infected hosts. Here, we present results of a survey of insectivorous bats from tropical Africa, including new isolates of species of the haemosporidian genus Nycteria. A hallmark of these parasites is their capacity to infect bat species of distinct families of the two evolutionary distant chiropteran suborders. We did detect Nycteria parasites in both rhinolophid and nycterid bat hosts in geographically separate areas of Sub-Saharan Africa, however our molecular phylogenetic analyses support the separation of the parasites into two distinct clades corresponding to their host genera, suggestive of ancient co-divergence and low levels of host switching. For one clade of these parasites, cytochrome b genes could not be amplified and cytochrome oxidase I sequences showed unusually high rates of evolution, suggesting that the mitochondrial genome of these parasites may have either been lost or substantially altered. This haemosporidian parasite-mammalian host system also highlights that sequential population expansion in the liver and gametocyte formation is a successful alternative to intermediate erythrocytic replication cycles.
寄生原生动物寄生虫已经进化出许多共同进化路径，以实现向其宿主种群的稳定传播。疟原虫属（Plasmodium spp.）是疟疾的病原体，相关的血孢子虫寄生虫是双翅目传播的真核病原体，它们会主动侵入并利用脊椎动物红细胞进行配子发生和无性发育，这通常会导致受感染宿主出现大量发病和死亡情况。在此，我们展示了对来自热带非洲的食虫蝙蝠的调查结果，包括血孢子虫属Nycteria物种的新分离株。这些寄生虫的一个特点是它们能够感染两个进化距离较远的翼手目亚目不同科的蝙蝠物种。我们在撒哈拉以南非洲地理上分开的地区的菊头蝠科和夜凹脸蝠科蝙蝠宿主中都检测到了Nycteria寄生虫，然而我们的分子系统发育分析支持将这些寄生虫分为两个不同的进化枝，分别对应它们的宿主属，这表明存在古老的共同分化以及低水平的宿主转换。对于这些寄生虫的一个进化枝，细胞色素b基因无法扩增，而细胞色素氧化酶I序列显示出异常高的进化速率，这表明这些寄生虫的线粒体基因组可能已经丢失或发生了重大改变。这种血孢子虫寄生虫 - 哺乳动物宿主系统还突出表明，在肝脏中的连续种群扩张和配子体形成是红细胞内复制周期的一种成功替代方式。
