Annenkova Nataliia V, Ahrén Dag, Logares Ramiro, Kremp Anke, Rengefors Karin
Limnological Institute Siberian Branch of the Russian Academy of Sciences 3, Ulan-Batorskaya St., 664033, Irkutsk, Russia.
Microbial Ecology Group, Department of Biology, Lund University, Ecology Building, SE-223 62, Lund, Sweden.
J Phycol. 2018 Aug;54(4):571-576. doi: 10.1111/jpy.12748. Epub 2018 Jun 13.
Recently radiated dinoflagellates Apocalathium aciculiferum (collected in Lake Erken, Sweden), Apocalathium malmogiense (Baltic Sea) and Apocalathium aff. malmogiense (Highway Lake, Antarctica) represent a lineage with an unresolved phylogeny. We determined their phylogenetic relationships using phylotranscriptomics based on 792 amino acid sequences. Our results showed that A. aciculiferum diverged from the other two closely related lineages, consistent with their different morphologies in cell size, relative cell length and presence of spines. We hypothesized that A. aff. malmogiense and A. malmogiense, which inhabit different hemispheres, are evolutionarily more closely related because they diverged from a marine common ancestor, adapting to a wide salinity range, while A. aciculiferum colonized a freshwater habitat, by acquiring adaptations to this environment, in particular, salinity intolerance. We show that phylotranscriptomics can resolve the phylogeny of recently diverged protists. This has broad relevance, given that many phytoplankton species are morphologically very similar, and single genes sometimes lack the information to determine species' relationships.
最近辐射的甲藻Apocalathium aciculiferum（采自瑞典厄肯湖）、Apocalathium malmogiense（波罗的海）和Apocalathium aff. malmogiense（南极公路湖）代表了一个系统发育未解决的谱系。我们基于792个氨基酸序列，通过系统发育转录组学确定了它们的系统发育关系。我们的结果表明，A. aciculiferum与其他两个密切相关的谱系不同，这与它们在细胞大小、相对细胞长度和刺的存在方面的不同形态一致。我们推测，栖息在不同半球的A. aff. malmogiense和A. malmogiense在进化上关系更密切，因为它们从海洋共同祖先分化而来，适应了广泛的盐度范围，而A. aciculiferum通过获得对这种环境的适应性，特别是对盐度不耐受，而定殖于淡水栖息地。我们表明，系统发育转录组学可以解析最近分化的原生生物的系统发育。鉴于许多浮游植物物种在形态上非常相似，而且单个基因有时缺乏确定物种关系的信息，这具有广泛的相关性。
