Feng Yun, Klahr Anja, Janik Paulina, Ronikier Anna, Hoppe Thomas, Novozhilov Yuri K, Schnittler Martin
Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University of Greifswald, Soldmannstr. 15, D-17487 Greifswald, Germany.
Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow, Poland.
Protist. 2016 Jun;167(3):234-53. doi: 10.1016/j.protis.2016.03.003. Epub 2016 Apr 5.
Specimens of the snowbank myxomycete Meriderma atrosporum agg. from five European mountain ranges were sequenced for parts of the nuclear small subunit ribosomal RNA gene (SSU) and the protein elongation factor 1 alpha gene (EF1A). A phylogeny of the EF1A gene, including a very variable spliceosomal intron, resulted in seven phylogroups, and this topology was confirmed by SSU sequences. Two thirds of all specimens were heterozygous for the EF1A gene, and the two haplotypes of these specimens occurred always in the same phylogroup. Except for two cases in closely related phylogroups all ribotypes were as well limited to one phylogroup. This pattern is consistent with the assumption of reproductively isolated sexual biospecies. Numbers of EF1A-haplotypes shared between mountain ranges correlate with geographical distance, suggesting relative isolation but occasional long-distance dispersal by spores. Most subpopulations (divided by putative biospecies and mountain ranges) were in Hardy-Weinberg equilibrium. A simulation assuming panmixis within but not in between subpopulations suggested that similar numbers of shared genotypes can be created by chance through sexual reproduction alone. Our results support the biospecies concept, derived from experiments with cultivable members of the Physarales. We discuss the results on the background of possible reproductive options in myxomycetes.
对来自欧洲五个山脉的雪堤黏菌Meriderma atrosporum agg.的样本，进行了核糖体RNA基因（SSU）的核小亚基部分和蛋白质延伸因子1α基因（EF1A）的测序。包括一个非常可变的剪接体内含子的EF1A基因的系统发育分析产生了七个系统发育组，并且这个拓扑结构通过SSU序列得到了证实。所有样本中有三分之二的EF1A基因是杂合的，并且这些样本的两种单倍型总是出现在同一个系统发育组中。除了在密切相关的系统发育组中有两个案例外，所有的核糖体型也都局限于一个系统发育组。这种模式与生殖隔离的有性生物种的假设一致。山脉之间共享的EF1A单倍型数量与地理距离相关，这表明相对隔离，但偶尔有孢子的长距离传播。大多数亚种群（按假定的生物种和山脉划分）处于哈迪-温伯格平衡。一个假设亚种群内部而非亚种群之间随机交配的模拟表明，仅通过有性繁殖就可能偶然产生相似数量的共享基因型。我们的结果支持了源自对绒泡菌目可培养成员实验的生物种概念。我们在黏菌可能的繁殖方式的背景下讨论了这些结果。
