CAREER: Discovering the Developmental Genetic Basis for Parallel Evolution of Aerial Respiration in Arthropods

从水到陆地的运动是脊椎动物和节肢动物（昆虫，蜘蛛，千足虫，甲壳类动物等）的关键进化转变。 不同的节肢动物群体使用不同的方法来呼吸空气，这是陆地生命的关键要求，至少在7个群体中分别发生了变化。 这个项目的目标是调查如何在多个节肢动物群体中分别进化出一个呼吸空气的呼吸系统。 空气呼吸的进化是否涉及改变每个组中相同的解剖结构和基因，或者每个节肢动物组使用不同的解决呼吸空气问题的方法？ 为了解决这个问题，我们将研究八种节肢动物呼吸器官的胚胎形成。 基因和蛋白质将被测试，以确定是否相同的基因在所有节肢动物的呼吸系统中使用。 基因组测序将进一步测试和鉴定创造独特呼吸结构的基因（例如，蜘蛛的书肺）。 这项研究的成果将被整合到一个新的实验室为基础的无脊椎动物学课程，每年通过动物学系教授，使用活标本。 将利用化石、基因和发育生物学的证据，开发一个关于节肢动物在陆地上运动的博物馆展览。 一名博士后研究员，一名研究生，和10个暑期本科生将在工作期间接受培训，强调招聘妇女和代表性不足的群体在science.Investigating平行演变的节肢动物的空气呼吸以前仅限于研究的功能形态或表达数据从几个类群。一些发育数据表明，下颚和螯肢呼吸系统是直接同源的，而一组单独的数据表明，呼吸器官的蛛形纲动物出现独立于修改步行腿。多足动物的呼吸系统还没有在发育遗传背景下进行过研究。为了解决节肢动物的内化呼吸系统的起源，拟议的工作将检查的位置，遗传和序列同源性的呼吸器官在8个新兴的模式节肢动物系统。为了建立蜘蛛类呼吸器官的系列同源性，将进行Hox错误表达实验以解除后段附属器的抑制。为了确定节肢动物中小管发生相关的基因调控网络（GRN）的保守程度，将对已知建立黑腹果蝇气管小管系统所需的候选基因进行基因表达测定。为了评估功能对应性，将在果蝇GRN中的五个关键基因的两个螯肢和三个下颚样本中进行敲低实验。为了研究蛛形纲动物书肺的模式化，将从蜘蛛和蝎子的书肺原基中产生比较转录组学数据，以鉴定一组参与书肺形态发生的新候选基因pupirin，用于进一步的功能筛选。这项工作将直接解决两个竞争的情况下，节肢动物terrestrialization坚持在文献中，使用独立的测试位置，序列和遗传同源性。

The movement from water to land was a critical evolutionary transformation for both vertebrates and arthropods (insects, spiders, millipedes, crustaceans, etc.). Different groups of arthropods used different methods to enable breathing air, a critical requirement for life on land, a change that occurred separately in at least 7 groups. The goal of this project is to investigate how an air-breathing respiratory system evolved separately in multiple arthropod groups. Did evolution of aerial respiration involve alteration to the same anatomical structures and genes in each group, or does each arthropod group use a different solution to the problem of breathing air? To resolve this question, the embryonic formation of respiratory organs in eight arthropod species will be investigated. Genes and proteins will be tested to determine whether the same genes are used in the respiratory system of all arthropods. Genome sequencing will further test and identify genes that create unique respiratory structures (e.g., the book lung of spiders). The outcomes of this research will be integrated into a new laboratory-based course on invertebrate zoology, to be taught annually through the Department of Zoology, using live specimens. A museum exhibit will be developed on the movement of arthropods onto land, and using evidence from fossils, genes, and developmental biology. One postdoctoral fellow, one graduate student, and ten summer undergraduates will be trained during the work, emphasizing recruitment of women and underrepresented groups in science.Investigating the parallel evolution of aerial respiration in Arthropoda has previously been limited to studies of functional morphology or expression data from a few taxa. Some developmental data suggest that mandibulate and chelicerate respiratory systems are directly homologous, whereas a separate set of data suggests that respiratory organs of arachnids arose independently from modified walking legs. Respiratory systems of Myriapoda have not been studied in a developmental genetic context at all. To resolve the origins of internalized respiratory systems of arthropods, the proposed work will examine positional, genetic, and serial homology of respiratory organs in eight emerging model arthropod systems. To establish the serial homology of arachnid respiratory organs, Hox misexpression experiments will be conducted to derepress appendages in posterior segments. To establish degree of conservation of the gene regulatory network (GRN) underlying tubulogenesis across Arthropoda, gene expression assays will be performed for candidate genes known to be required for establishment of the Drosophila melanogaster tracheal tubule system. To assess functional correspondence, knockdown experiments will be conducted in two chelicerate and three mandibulate exemplars for five critical genes in the Drosphila GRN. To investigate the patterning of the arachnid book lung, comparative transcriptomic data will be generated from book lung primordia of spiders and scorpions, toward identifying a set of novel candidate genes putatively involved in book lung morphogenesis for further functional screening. This work will directly address the two competing scenarios of arthropod terrestrialization that persist in the literature, using independent tests of positional, serial, and genetic homology.