WGDI: A user-friendly toolkit for evolutionary analyses of whole-genome duplications and ancestral karyotypes

Evidence of whole-genome duplications (WGDs) and subsequent karyotype changes has been detected in most major lineages of life on Earth. To clarify the complex resulting multiple-layered patterns of gene collinearity in genome analyses there is a need for convenient and accurate toolkits. To meet this need, we introduce here WGDI ( W hole- G enome D uplication I ntegrated analysis), a Python-based command-line tool that facilitates comprehensive analysis of recursive polyploidizations and cross-species genome alignments. WGDI supports three main workflows (polyploid inference, hierarchical inference of genomic homology, and ancestral chromosomal karyotyping) that can improve detection of WGD and characterization of related events. It incorporates a more sensitive and accurate collinearity detection algorithm than previous softwares, and can accelerate WGD-related karyotype research. As a freely available toolkit at GitHub ( https://github.com/SunPengChuan/wgdi ), WGDI outperforms similar tools in terms of efficiency, flexibility and scalability. In an illustrative example of its application, WGDI convincingly clarified karyotype evolution in Aquilegia coerulea and Vitis vinifera following WGDs and rejected the hypothesis that Aquilegia contributed as a parental lineage to the allopolyploid origin of core dicots.