Diversität und Evolution Antarktischer Gastropoden: ein genomischer Ansatz

南极腹足动物的多样性和进化：基因组方法

• 批准号: 238768991
• 负责人: Professor Dr. Michael Schrödl
• 金额: --
• 依托单位: School of Biological Sciences
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/238768991?language=en
• 关键词: Diversit; und; Evolution; Antarktischer; Gastropoden

The Antarctic irwertebrate fauna appears highiy diverse, but is only localiy and sporadically explored - and already threatened by global climate change. Gastropods are abundant, species rieh, ecologically and economically irnportant, count with a rieh fossil record and are wellestablished äs model organisms for many scientific disciplines. Most of the roughly 600 Antarctic gastropod species are regarded valid at the mornent based on shell features of often just a few or single specimens. Intraspecific morphological variability, soft pari anatomy, biology» and ecology are usually unknown, and many synonyms have been proposed. Wolecular data are limited to CÖI barcode sequences of few individuals of the more common species: Phylogenetic analyses of single genes suggest complexes of cryptic species or deep lineages, which may show distinct geographic distributions and special ecological niches. Rarity of species or samples prohibits general population genetics approaches. The prirnary goal of our herein proposed project is revealing the species diversity of Antarctic gastropods comprehensively and reliably. In addition to mltochondrial CÖI, we will use next generation sequencing (NGS) and newly established methods (double digest Restriction Associated DMA sequencing, ddRADseq) to efficiently generate a multitude of independent nuclear genomic sequence markers. We will include all species and subsamples from rnore than 2000 Southern Öcean gastropod samples available at the ZSM Mollusca collection suitable for genetic studies, plus further material to be collected at expeditions or from other museums. We will perform phylogenetic analyses (ML, Bayes, in subgroups BEST) and combined, up~to-date molecular species delimitation approaches {ABGD, GMYCS BP&P), An integrative taxonomic approach reiying on congruence will be applied to revea! conservative and reliable evolutionary species units, which will be used for diversity analyses, We will also explore genomic evolutionary archives of seiected gastropod lineages performing fossil-calibrated BEAST chronograms. The dynamics of diversification will be analyzed via recent Birth-Death-Shift models, and historical biogeography will be reconstructed using recent Software (e.g, RASP). With our massif genomic data from many subtaxa we will test current paradigms on biogeography and evolution, such äs glacial cycles causing an "Antarctic speciation pump", and evaluate competing hypotheses on glacial refuges and migration scenarios. The herein proposed combination of ddRADseqs with up~to~date multi-iocus analyses is novel, extremely cost and time effective, and can include thousands instead of few specimens» without any a priori selectron. It is expected to be very powerful to delimitate newty collected, unrecognized, or cryptic species, even jf badly sampled or just represented by singletons. We trust this approach is a quantum leap forward referring to the exploration of remote and highiy diverse faunas, Our pioneer project thus will generate massif novel and comprehensive data and results on Antarctic gastropods which might change previous ideas on e.g. biogeography or ecology, that aimost entirely relted on ill-defined „morphospecies" concepts, Eventually, evolutionary species units will be characterized morphologically, geographicaliy and ecologically. This will be the basis for future studies on past evolutionary adaptations, ecological niche rnodelling, and predicting response to global change and ocean acidification.

南极无脊椎动物群似乎高度多样化，但只是局部和零星的探索-并且已经受到全球气候变化的威胁。腹足类是丰富的，物种rieh，生态和经济上的重要性，计数与rieh化石记录，并为许多科学学科的模式生物。在南极洲的大约600种腹足类中，大多数都被认为是有效的，因为它们的外壳特征往往只是少数或单个标本。种内形态变异、软壁解剖学、生物学和生态学通常是未知的，并且已经提出了许多同义词。分子数据仅限于更常见物种的少数个体的CÖI条形码序列：单基因的系统发育分析表明隐藏物种或深层谱系的复合体，可能显示出不同的地理分布和特殊的生态位。由于物种或样本稀少，无法采用一般群体遗传学方法。全面、可靠地揭示南极腹足类的物种多样性是本项目的首要目标。除了multocomial CÖI，我们将使用下一代测序（NGS）和新建立的方法（双消化限制性相关DMA测序，ddRADseq）来有效地产生大量独立的核基因组序列标记。我们将包括来自ZSM软体动物收藏馆的2000多个适合遗传研究的南大洋腹足类样本的所有物种和子样本，以及在探险或其他博物馆收集的进一步材料。我们将进行系统发育分析（ML，贝叶斯，在亚组最好的）和组合，最新的分子物种界定方法（ABGD，GMYCS BP&P），一个综合的分类学方法依赖于一致性将被应用于揭示？保守和可靠的进化物种单位，这将用于多样性分析，我们还将探索选择腹足类谱系的基因组进化档案进行化石校准BEAST年表。多样化的动态将通过最近的死亡转移模型进行分析，历史地理将使用最新的软件（如RASP）重建。与我们的基因组数据从许多亚分类群，我们将测试目前的范式对地理和进化，这样的冰川周期造成的“南极物种形成泵”，并评估冰川避难所和迁移的情况下竞争的假设。本文提出的ddRADseq与最新的多基因座分析的组合是新颖的，非常节省成本和时间，并且可以包括数千个而不是几个样本，而没有任何先验选择器。它被认为是非常强大的界定新的收集，未识别的，或神秘的物种，即使是jf不好的采样或只是代表的单例。我们相信这种方法是对遥远和高度多样的动物群探索的一个巨大飞跃。因此，我们的先驱项目将产生关于南极腹足动物的大量新颖和全面的数据和结果，这可能会改变以前关于例如地理学或生态学的想法，这些想法几乎完全与定义不清的“形态种”概念有关。最终，进化的物种单位将在形态上被表征，地理上和生态上。这将是未来研究过去的进化适应，生态位建模，并预测对全球变化和海洋酸化的反应的基础。