College of Life Science and Technology, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Jinan University, Guangzhou, China.
Microbiol Spectr. 2024 May 2;12(5):e0236723. doi: 10.1128/spectrum.02367-23. Epub 2024 Apr 4.
Species delimitation based on lineage definition has become increasingly popular. However, these methods have been limited, especially for species that lack genomic data and are morphologically similar. The trickiest part for the species identification is that the interspecific and intraspecific boundaries are vague. Taking (Dinophyta) as an example, analysis of cell morphology, growth, and toxin synthesis in both species of and does not provide a reliable basis for species delineation. However, through phylogenetic and genetic distance analyses of their ITS and LSU sequences, establishment of evolutionary tree based on orthologous gene sequences, and combining the results of automatic barcode gap discovery and Poisson tree processes models, it was sustained that does not belong to the complex and should be considered as an independent species. Interspecies genetic evolution analysis revealed that and may contribute to evolutionary direction that favors combating reverse environmental factors. In , viral invasion may be one of the reasons for its large genome size. In the study, complex has been selected as an example to enhance the taxonomic identification of microalgae through molecular and genetic evolution, offering valuable insights into refining taxonomic identification and promoting microbial biodiversity research in other species.IMPORTANCEMicroalgae, especially the species known as , have received significant attention due to their ability to trigger harmful algal blooms and produce toxins. However, the boundaries between species and within species are ambiguous. Clear and comprehensive species delineation indicates that should be considered as an independent species, separate from the complex. Improving the classification and identification of microalgae through molecular and genetic evolution will provide reference points for other cryptic species. occupy multiple ecological niches in marine environments, and studying their evolutionary direction contributes to understanding their ecological adaptations and community succession.
基于谱系定义的物种划分方法已越来越受欢迎。然而，这些方法存在局限性，尤其是对于缺乏基因组数据且形态相似的物种。物种鉴定最棘手的部分是种间和种内边界模糊。以（Dinophyta）为例，对 和 两个物种的细胞形态、生长和毒素合成进行分析，不能为物种划分提供可靠依据。然而，通过对 ITS 和 LSU 序列的系统发育和遗传距离分析、基于同源基因序列构建进化树，以及结合自动条码间隙发现和泊松树过程模型的结果，证明 不属于 复合体，应被视为独立的物种。种间遗传进化分析表明， 和 可能有助于对抗反向环境因素的进化方向。在 中，病毒入侵可能是其基因组较大的原因之一。本研究以 复合体为例，通过分子和遗传进化增强微藻的分类鉴定，为细化分类鉴定提供了有价值的见解，并促进了其他物种的微生物生物多样性研究。重要性微藻，特别是被称为 的物种，由于其引发有害藻华和产生毒素的能力而受到广泛关注。然而，物种之间和物种内部的界限是模糊的。明确和全面的物种划分表明， 应被视为一个独立的物种，与 复合体分开。通过分子和遗传进化改进微藻的分类和鉴定将为其他隐种提供参考点。 在海洋环境中占据多个生态位，研究它们的进化方向有助于理解它们的生态适应和群落演替。
