Transformations in the evolution of Peracarida (Crustacea)

甲壳类（甲壳纲）进化的转变

• 批准号: 520989936
• 负责人: Professor Dr. Stefan Richter
• 金额: --
• 依托单位: Lehrstuhl für Allgemeine und Spezielle Zoologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/520989936?language=en
• 关键词: Transformations; evolution; Peracarida; Crustacea

Peracarida is a highly diverse and ecologically important group of malacostracan crustaceans. Morphologically, Peracarida is well characterized by a marsupium in which female’s hatch and rear embryonized larvae/juveniles. However, their monophyly was repeatedly questioned in molecular phylogenetic studies and no consensus has been reached regarding their internal relationships. The evolution of the intra-marsupial development had far reaching micro- and macroevolutionary consequences. In contrast to many other predominantly marine taxa, Peracarida lacks a dedicated dispersal stage, which increases population fragmentation, and Peracarida shifted from a reproductive r-strategy to a k-strategy. By altering the effective population size, this has long-term consequences for their rate of molecular evolution, as previously observed. The evolution of the marsupium also had consequences for the locomotion of peracarids, which is reflected in the morphology of the pleon. Shifts between habitats (like freshwater, terrestrial, or shallow-water marine and deep sea) might have similar long-term effects on the rate of molecular evlution. Hypotheses / research questions / objectives: Our key objectives are: Resolve the internal relationships within Peracarida and test their monophyly in a combined (morphological + molecular) approach. Understand the evolutionary transformation of the locomotory apparatus (thoracopods and pleon) in Peracarida as a result of the evolution of the marsupium. Identify long-term changes in the rate of molecular evolution in relation to the reproductive strategy or transitions between habitats in Isopoda. Approach / methods: We will combine modern morphological (μCT, cLSM and histology) and genomic (transcriptome sequencing and target capture) methods and will study up to 240 species (depending on the method). This will allow the most detailed reconstruction of the evolutionary history of Peracarida to date as well as tracing key morphological transitions and identifying long-term changes in the molecular substitution rate (including comparisons between protein-coding and non-coding loci and between synonymous and non-synonymous substitutions). The research will be conducted in Rostock (Germany) and Vienna (Austria). Level of originality / innovation: This will be the first project to combine morphological and phylogenomic analyses to resolve the relationships within Peracarida. A particular novelty is the usage of the vast genomic data sets to gain insights into genome evolutionary processes in addition to resolving the phylogenetic relationships. The latter will be of importance not only for Peracarida, but will help to better understand the long-term effects of life-history changes on rates of molecular evolution in general.

Peracarida是一个高度多样性和生态上重要的软甲甲壳动物群体。在形态学上，Peracarida的特征是有袋动物，其中雌性的孵化和后胚胎化的幼虫/幼虫。然而，它们的单系性在分子系统学研究中一再受到质疑，关于它们的内部关系也没有达成共识。有袋类内部发展的进化具有深远的微观和宏观进化后果。与许多其他主要的海洋分类群相比，掌螨目缺乏专门的扩散阶段，这增加了种群的碎片化，并且掌螨目从生殖r策略转变为k策略。通过改变有效群体大小，这对它们的分子进化速率产生了长期影响，正如以前观察到的那样。有袋类的进化也影响了有孔虫的运动，这反映在pleon的形态上。栖息地（如淡水，陆地，或浅水海洋和深海）之间的变化可能对分子进化的速度有类似的长期影响。假设/研究问题/目标：我们的主要目标是：解决内Peracarida的内部关系，并测试其单系在一个组合（形态+分子）的方法。了解有袋动物演化的结果，即在Peracarida中，运动器官（胸足类和pleon）的演化转变。确定长期变化的分子进化速率与生殖策略或栖息地之间的过渡等足类。方针/方法：我们将结合联合收割机现代形态学（μCT，cLSM和组织学）和基因组学（转录组测序和靶捕获）方法，并将研究多达240个物种（取决于方法）。这将允许最详细的重建Peracarida的进化历史，以及跟踪关键的形态转变，并确定长期变化的分子置换率（包括蛋白质编码和非编码基因座之间的比较，同义和非同义置换）。研究将在罗斯托克（德国）和维也纳（奥地利）进行。独创性/创新水平：这将是第一个结合联合收割机形态学和基因组学分析来解决Peracarida内部关系的项目。一个特别的新奇是使用大量的基因组数据集，以获得深入了解基因组进化过程，除了解决系统发育关系。后者不仅对Peracarida具有重要意义，而且将有助于更好地了解生活史变化对一般分子进化速率的长期影响。