Avian malaria on Madagascar: delimiting local species using an integrative approach combining genetic, morphological and host specificity data

禽疟疾是一种由血孢子虫目（血孢子虫亚门：顶复门）的单细胞血液寄生虫引起的疾病。寄生虫的生命周期是专性异源的，这意味着寄生虫需要两个不同的宿主（中间宿主和终末宿主）才能成功完成其生命周期。在禽血孢子虫寄生虫的情况下，鸟类是中间宿主，吸血双翅目昆虫是媒介（最终宿主）。有三种不同的血孢子虫属感染鸟类：疟原虫，血变形菌和Leucocytozoon。到目前为止，分子研究已经确定了近4,000种独特的鸟类血孢子虫谱系，即全世界的单倍型，在1,800多种鸟类和350种载体中检测到。然而，相比之下，只有103个形态学描述的物种，近4000个谱系中的228个可以被分配（Malavi，http：//mbio-serv2.mbioekol.lu.se/Malavi;截至2019年11月）。这一缺陷是由于在鸟类血孢子虫领域没有明确的物种描述规则。最新和最有前途的物种鉴定方法是一种综合方法，将分子，形态学和生态学数据结合在一起（Galen et al. 2018）。在所要求的项目中，将对2003 - 2021年在马达加斯加Maromizaha雨林收集的马达加斯加鸟类种群的大约1700份血液样本进行检查，以确定是否可能存在白细胞虫感染。有针对性的检查属Leucocytozoon应提供一个有意义的声明，在马达加斯加鸟类种群的实际患病率，并完成以前的研究数据集。由于地方性鸟类物种数量众多，预计将发现白细胞虫谱系的高度多样性。对同一鸟类种群的800多份血涂片进行检查，将阐明通过PCR方法检测到的哪些寄生虫（在本项目期间和我们之前的研究中（Musa et al. 2019））可以在鸟类宿主中繁殖，以及在哪些情况下检测到流产感染。此外，配子母细胞的形态学检测和测量将是进一步分析的基础。在我们的最新研究中提出了至少12种新的血孢子虫寄生虫物种（Musa等人，2019年），沿着数量仍然未知的白细胞虫物种（数据将在本项目期间获得）存在于马达加斯加。这些物种将使用综合方法进行描述，该方法结合了形态学数据，各种遗传标记的分子数据和生态学数据，如宿主特异性（遵循Galen et al. 2018）。

Avian malaria is a disease caused by unicellular blood parasites of the order Haemosporida (subphylum: Apicomplexa). The parasites life cycles are obligate heteroxenous, meaning the parasites need two different hosts (intermediate and definitive host) to successfully fulfill their life cycles. In case of avian haemosporidian parasites, birds are the intermediate host and blood-sucking dipterans are the vectors (definitive hosts). There are three different haemosporidian genera infecting birds: Plasmodium, Haemoproteus and Leucocytozoon. So far, molecular studies have identified nearly 4,000 unique avian haemosporidian lineages i.e. haplotypes worldwide, detected in over 1,800 bird species and 350 vectors. In contrast, however, there are only 103 morphologically described species, to which 228 of the nearly 4000 lineages can be assigned (MalAvi, http://mbio-serv2.mbioekol.lu.se/Malavi; as of November 2019). This shortcoming is due to the fact that there have been no clear rules for species descriptions in the field of avian Haemosporida. The latest and most promising method for species identification is an integrative approach that brings together molecular, morphological and ecological data (Galen et al. 2018).In the requested project approximately 1700 blood samples of a Malagasy bird population, collected between 2003 - 2021 in the Maromizaha rainforest on Madagascar, will be examined for possible Leucocytozoon infection. The targeted examination of the genus Leucocytozoon should provide a meaningful statement about the actual prevalence in the Malagasy bird population and complete the data set of previous studies. Due to the high number of endemic bird species, it is expected that a high diversity of Leucocytozoon lineages will be found. The examination of more than 800 blood smears of the same bird population will clarify which parasites detected by PCR method (during this project and in our previous study (Musa et al. 2019)) can reproduce in the bird host and in which cases an abortive infection was detected. Moreover, the morphological detection and measurements of the gametocytes will be the basis for further analyses. At least 12 new haemosporidian parasite species, proposed in our latest study (Musa et al., 2019), along with a still unknown number of Leucocytozoon species (data will be obtained during this project) exist on Madagascar. These species will be described using an integrative approach that combines morphological data, molecular data of various genetic markers and ecological data such as host specificity (following Galen et al. 2018).