title: What an Intron May Tell: Several Sexual Biospecies Coexist in Meriderma spp. (Myxomycetes).
abstract: 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.
authors.affiliation: Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University of Greifswald, Soldmannstr. 15, D-17487 Greifswald, Germany.
authors.forename: Yun
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University of Greifswald, Soldmannstr. 15, D-17487 Greifswald, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Klahr
authors.affiliation: Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Janik
authors.affiliation: Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Ronikier
authors.affiliation: Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University of Greifswald, Soldmannstr. 15, D-17487 Greifswald, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoppe
authors.affiliation: V.L. Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov St. 2, 197376 St. Petersburg, Russia.
authors.forename: Yuri K
authors.initials: YK
authors.lastname: Novozhilov
authors.affiliation: Institute of Botany and Landscape Ecology, Ernst Moritz Arndt University of Greifswald, Soldmannstr. 15, D-17487 Greifswald, Germany. Electronic address: martin.schnittler@uni-greifswald.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Schnittler
mesh_terms: D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006239:Haplotypes; D006579:Heterozygote; D007438:Introns; D009235:Myxomycetes / Q000235:genetics* / Q000254:growth & development* / Q000302:isolation & purification; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D011995:Recombination, Genetic; D021521:Ribotyping; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D020648:Peptide Elongation Factor 1; D012337:RNA, Ribosomal, 18S
keywords: Protein elongation factor 1 alpha; nuclear small subunit ribosomal RNA; plasmodial slime molds; reproductive system; speciation.; spliceosomal intron