Pattern and processes of cichlid speciation along a geographical gradient in the Lower Congo River: Are species complex genomic networks?

刚果河下游沿地理梯度的慈鲷物种形成的模式和过程：物种复杂的基因组网络吗？

• 批准号: 46567454
• 负责人: Professor Dr. Bernhard Misof, Ph.D.
• 金额: --
• 依托单位: Leibniz-Institut zur Analyse des Biodiversitätswandels (LIB)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/46567454?language=en
• 关键词: Pattern; processes; cichlid; speciation; along

Inter- and intraspecific gene flow is increasingly recognized as an important factor shaping diversification and speciation. We study the phylogeny, phylogeography and population genomics of five small cichlid species assemblages (Teleostei: Cichlidae; 3-10 species each) endemic to the rapids of the Lower Congo River. The parallel evolution of five morphological and/or ecological divergent lineages of the genera Steatocranus, Nanochromis, Haplochromis, Teleogramma and Lamprologus within the contiguous unidirectional topography of the Lower Congo River allows testing of speciation with gene flow and hybrid speciation hypotheses under parapatric and partially sympatric geographical settings. Building on own previous phylogeographic and morphometric results, we will take advantage of Next Generation Sequencing, stable isotope analysis and geometrical morphometrics to assess genome-phenotype-environment associations for each cichlid assemblage along an approximately 16 km long stretch of the Lower Congo River at the rapids of Inga. This approach will give us the opportunity (1) to identify and compare genomic signatures of adaptive vs. non-adaptive parapatric population divergence across species under identical conditions. It will further allow to (2) identify and analyze changes of genomic architecture after secondary introgression and, in at least one case, after homoploid hybrid speciation, which most likely took place after secondary contact of previously allopatric lineages. The study will contribute to the general understanding of the role of introgression and hybridization for the origin of new species.

种间和种内基因流动日益被认为是形成多样化和物种形成的一个重要因素。我们研究了五个小的慈鲷物种组合（真骨鱼：慈鲷科; 3-10种）特有的下刚果河的急流的繁殖，繁殖地理和人口基因组学。五个形态和/或生态的不同谱系的属Steatocranus，Nanochromis，Haplochromis，Teleogramma和Lamprologus内的连续单向地形的下刚果河的平行进化允许测试的物种形成与基因流和杂交物种形成的假设下parapatric和部分同域的地理环境。建立在自己以前的地理和形态测量的结果，我们将利用下一代测序，稳定同位素分析和几何形态测量，以评估基因组表型环境协会为每个慈鲷组合沿着约16公里长的延伸下刚果河在因加的急流。这种方法将使我们有机会（1）在相同条件下识别和比较不同物种之间适应性与非适应性的群体差异的基因组特征。它将进一步允许（2）识别和分析二次基因渗入后基因组结构的变化，并且在至少一种情况下，在同倍体杂交物种形成后，这很可能发生在之前异地谱系的二次接触之后。该研究将有助于人们对渐渗和杂交在新物种起源中的作用的普遍理解。