Is genome downsizing associated with diversification in polyploid lineages of Veronica
Is genome downsizing associated with diversification in polyploid lineages of Veronica
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DOI：
10.1111/boj.12276
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发表时间：
2015-06
影响因子：
2.4
通讯作者：
Heidi M. Meudt;Blanca M. Rojas-Andrés;Jessica M. Prebble;Evonne Low;P. Garnock-Jones;D. Albach
中科院分区：
文献类型：
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作者：
Heidi M. Meudt;Blanca M. Rojas-Andrés;Jessica M. Prebble;Evonne Low;P. Garnock-Jones;D. Albach
在相关多倍体和二倍体谱系的系统发育背景下研究基因组大小进化可以帮助我们了解基因组大小变化的优点和缺点及其对多样化的影响。在这里，我们贡献了199个新的DNA序列和近三倍的基因组大小估计在多倍体和二倍体婆婆纳（Plantinaceae）（128种，c。30%的属），以提供全面的基线来探索基因组大小变化的影响。构建了内转录间隔区（ITS）和trnL-trnL-trnF系统发育树，并进行了系统发育广义最小二乘法（PGLS）、祖先性状状态重建、分子测年和多样性分析。婆婆纳1C值范围从0.26至3.19 pg。生活史与1C值显着相关，而倍性和染色体数目与1C和1Cx值密切相关。估计的祖先婆婆纳1Cx值为0.65 pg，在多倍体南半球亚属Pseudoveronica和两个北方半球亚属中具有显著的基因组缩小，并且在两个二倍体亚属中具有显著的基因组增大。这些基因组缩小事件伴随着多样化率的增加，但“核心转移”只检测到亚属Pseudoveronica的速度。多倍性在该属的进化中是重要的，并假设基因组缩小和多倍体多样性与物种辐射之间存在联系。© 2015伦敦林奈学会，林奈学会植物学杂志，2015，178，243-266。
The study of genome size evolution in a phylogenetic context in related polyploid and diploid lineages can help us to understand the advantages and disadvantages of genome size changes and their effect on diversification. Here, we contribute 199 new DNA sequences and a nearly threefold increase in genome size estimates in polyploid and diploid Veronica (Plantaginaceae) (to 128 species, c. 30% of the genus) to provide a comprehensive baseline to explore the effect of genome size changes. We reconstructed internal transcribed spacer (ITS) and trnL-trnL-trnF phylogenetic trees and performed phylogenetic generalized least squares (PGLS), ancestral character state reconstruction, molecular dating and diversification analyses. Veronica 1C-values range from 0.26 to 3.19 pg. Life history is significantly correlated with 1C-value, whereas ploidy and chromosome number are strongly correlated with both 1C- and 1Cx-values. The estimated ancestral Veronica 1Cx-value is 0.65 pg, with significant genome downsizing in the polyploid Southern Hemisphere subgenus Pseudoveronica and two Northern Hemisphere subgenera, and significant genome upsizing in two diploid subgenera. These genomic downsizing events are accompanied by increased diversification rates, but a ‘core shift’ was only detected in the rate of subgenus Pseudoveronica. Polyploidy is important in the evolution of the genus, and a link between genome downsizing and polyploid diversification and species radiations is hypothesized. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 243–266.