Do genomic regions under selection have hybrid origins in cichlids?

慈鲷中选择的基因组区域是否具有杂交起源？

• 批准号: NE/K000829/1
• 负责人: Domino Joyce
• 金额: $ 8.34万
• 依托单位: University of Hull
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK000829%2F1
• 关键词: Do; genomic; regions; under; selection

Hybridization is increasingly recognised as a creative evolutionary force because ecologically useful genomic attributes from one species can be easily obtained from another without waiting for mutation and fixation. However, we currently lack evidence that such genetic contributions could be preferentially retained through natural selection- hybridization maybe a consequence rather than a cause of speciation. In particular, the role that hybridization plays in the generation of hundreds of species in adaptive radiations is unclear. Recent advances in genome technologies make studying this process in detail an exciting possibility - DNA technology can identify "genomic islands of speciation"- loci under selection (or linked to regions under selection) which show divergence between species relative to the rest of the genome. Crucially, the genetic contributions of these adaptively important genetic regions from divergent founding lineages can then be identified in adaptive radiations. In this proposal, I plan to demonstrate that the "text book" Lake Malawi cichlid fish radiation consists of collections of adaptively important genomic regions from different sources. The project will capitalise on the recent Astatotilapia burtoni cichlid genome sequence, advancing our understanding by genome-wide screening of more than 20 species at once in order to identify tens of thousands of single nucleotide polymorphisms (SNPs) using RAD-tag sequencing. Genome scans will identify regions of the genome important in adaptation, and I will then test whether these regions in the endemic radiation lineages show a signal of hybridization with putative seeding lineages, compared to "neutral" regions. This approach will be the first evidence to demonstrate that loci under selection in an adaptive radiation have distinct origins, confirming the importance of hybridization as a driving force for adaptive change.

杂交越来越被认为是一种创造性的进化力量，因为一个物种的生态有用的基因组属性可以很容易地从另一个物种那里获得，而不需要等待突变和固定。然而，我们目前缺乏证据表明，这种遗传贡献可以通过自然选择优先保留-杂交可能是物种形成的结果而不是原因。特别是，杂交在适应辐射的数百个物种的产生中所起的作用尚不清楚。基因组技术的最新进展使详细研究这一过程成为一种令人兴奋的可能性--DNA技术可以识别“物种形成的基因组岛”--被选择的(或与被选择的区域相关联的)基因座，这些基因座显示了物种之间相对于基因组其他部分的差异。至关重要的是，这些来自不同创始谱系的适应性重要遗传区域的遗传贡献可以在适应性辐射中识别出来。在这项提案中，我计划证明“教科书”马拉维湖慈济鱼辐射由来自不同来源的具有适应性的重要基因组区域的集合组成。该项目将利用最近的波罗非鱼Cichlid基因组序列，通过一次对20多个物种进行全基因组筛选来促进我们的理解，以便使用RAD-Tag测序来识别数万个单核苷酸多态(SNPs)。基因组扫描将确定基因组中在适应中重要的区域，然后我将测试地方性辐射谱系中的这些区域是否显示出与假定的播种谱系杂交的信号，而不是“中性”区域。这一方法将是第一个证明在适应性辐射中被选择的基因座具有不同起源的证据，证实了杂交作为适应性变化的驱动力的重要性。

项目成果

The genomic basis of cichlid fish adaptation within the deepwater "twilight zone" of Lake Malawi.

• DOI: 10.1002/evl3.20
• 发表时间: 2017-09
• 期刊: Evolution letters
• 影响因子: 5
• 作者: Hahn C;Genner MJ;Turner GF;Joyce DA
• 通讯作者: Joyce DA

The genomic basis of adaptation to the deep water 'twilight zone' in Lake Malawi cichlid fishes

马拉维湖丽鱼适应深水“暮光区”的基因组基础

• DOI: 10.1101/102830
• 发表时间: 2017
• 作者: Hahn C