Phylogeography of Verrucarum sand fly disease vectors

描述（由申请人提供）：在全球范围内，毁容的皮肤形式的利什曼病产生2000万至4000万人间病例，并且完全通过受感染的白蛉沙蝇的叮咬传播。利什曼病是整个新世界热带地区的地方病，目前在农村、森林和郊区地区显著增加。第二种沙蝇媒介疾病巴尔通体病是南美洲安第斯山脉的一大祸害，病例集中在秘鲁——未经治疗的病例死亡率高达80%。目前的建议侧重于沙蝇科（沙蝇属）的28种沙蝇，其中包括至少17种已知或疑似的一种或多种上述疾病的媒介。具体目的如下：(1)比较疣状菌属2种分布最广的疣状菌（巴尔通菌病媒介）和serrana（可能的皮肤利什曼病媒介）的种群遗传结构，利用可变线粒体基因序列（cytb）检测隐匿种，评价地理屏障和线性距离对遗传分化的相对意义。(2)利用DNA序列、杂交和同工酶等全证据方法，对形态几乎相同的种（6种townsendi和2种serrana）的遗传亲缘关系进行了研究。(3)通过线粒体（12SrDNA, COl）和核基因序列（18SrDNA, 28SrDNA, ITS2）的比较，推测疣子属及其相关亚属和属的分子系统发育。(4)使用推断的系统发育，通过测试它们的单系性来验证形态学上定义的物种、系列、亚属和属定义。(5)推断该类群的地理和生态联系的进化史。(6)建立快速鉴定沙蝇类群的分子工具。解决这些问题将有助于深入了解沙蝇种群的遗传结构和地理隔离的影响。它将测试形态分类是否被系统发育历史所证明。从生成的一套遗传图谱中，物种鉴定和物种真实性将得到促进。一个大型和医学上重要的群体，疣状兽类，将澄清系统发育关系。对Lutzomyia属近400种植物间的关系有了更广阔的认识。更好地了解这些分析提供的分类和系统发育关系将直接导致更现实的疾病风险评估和对环境对沙蝇进化影响的细微差别的新见解。

DESCRIPTION (provided by the applicant): Globally, the disfiguring, cutaneous form of leishmaniasis produces 20-40 million human cases and is transmitted exclusively by the bite of infected phlebotomine sand flies. Leishmaniasis is endemic throughout the New World tropics, and it is now increasing noticeably in rural, forested and suburban settings. A second sand fly-vectored disease, bartonellosis, is a scourge of the South American Andes with cases concentrated in Peru--it has a high fatality ratio >80% in untreated cases. The current proposal focuses on the 28 sand fly species of the Verrucarum group (in the genus Lutzomyia), which includes at least 17 known or suspected vectors of one or more of these diseases. The specific aims are as follows: (1) To compare the population genetic structure of 2 of the most widely distributed members of the Verrucarum group, Lutzomyia verrucarum (bartonellosis vector) and Lutzomyia serrana (probable cutaneous leishmaniasis vector), in order to detect cryptic species and evaluate the relative significance of geographic barriers and linear distance to genetic differentiation using variable mitochondrial gene sequences (cytb). (2) To investigate genetic relatedness among morphologically almost identical species (6 species of the s. townsendi and 2 species of the s. serrana) using total evidence approaches--DNA sequences, hybridization and isoenzymes. (3) To infer a molecular phylogeny for species of the Verrucarum group and related subgenera, and genera, based on comparison of mitochondrial (12SrDNA, COl) and nuclear gene sequences (18SrDNA, 28SrDNA, and ITS2). (4) To use the inferred phylogeny for verifying morphologically defined species, series, subgenera, and genera definitions, by testing their monophyly. (5) To deduce the evolutionary history of geographical and ecological associations of this group of taxa. (6) To develop molecular tools for a rapid identification of sand fly taxa. Resolution of these aims will provide insights into sand fly population genetic structure, and effects of geographic isolation. It will test if morphological classifications are justified by phylogenetic history. From the suite of genetic profiles generated, species identification and species authenticity will be facilitated. The phylogenetic relationships of a large and medically important group, Verrucarum, will be clarified. A broader perspective to the relationships among the nearly 400 species in the genus Lutzomyia will be established. A better understanding of the taxonomic and phylogenetic relationships provided by these analyses will lead directly to more realistic assessments of disease risk and new insights into the nuances of environmental effects on sand fly evolution.