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Two-gene phylogeny of bright-spored Myxomycetes (slime moulds, superorder Lucisporidia).

Fiore-Donno AM, Clissmann F, Meyer M, Schnittler M, Cavalier-Smith T - PLoS ONE (2013)

Bottom Line: We discuss possible evolutionary pathways.Our study fills a gap in the phylogeny of Amoebozoa and provides an extensive SSU rRNA sequence reference database for environmental sampling and barcoding.We report a new group I intron insertion site for Myxomycetes in one Licea.

View Article: PubMed Central - PubMed

Affiliation: Zoology Department, University of Oxford, Oxford, United Kingdom. afiore-donno6@infomaniak.ch

ABSTRACT
Myxomycetes, or plasmodial slime-moulds, are one of the largest groups in phylum Amoebozoa. Nonetheless, only ∼10% are in the database for the small subunit (SSU) ribosomal RNA gene, the most widely used gene for phylogenetics and barcoding. Most sequences belong to dark-spored Myxomycetes (order Fuscisporida); the 318 species of superorder Lucisporidia (bright-spored) are represented by only eleven genuine sequences. To compensate for this, we provide 66 new sequences, 37 SSU rRNA and 29 elongation factor 1-alpha (EF-1α), for 82% of the genera of Lucisporidia. Phylogenetic analyses of single- and two-gene alignments produce congruent topologies and reveal both morphological characters that have been overemphasised and those that have been overlooked in past classifications. Both classical orders, Liceida and Trichiida, and several families and genera are para/polyphyletic; some previously unrecognised clades emerge. We discuss possible evolutionary pathways. Our study fills a gap in the phylogeny of Amoebozoa and provides an extensive SSU rRNA sequence reference database for environmental sampling and barcoding. We report a new group I intron insertion site for Myxomycetes in one Licea.

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Four different capillitial threads in Trichiida.A. Capillitial threads of Trichia varia: isolated threads sculptured with spiral bands, two very short ones are indicated by a black line. B. Capillitial threads of Arcyria obvelata, forming a network and sculptured with spines. C. Capillitial threads of Oligonema flavidum, short and in this case branched, smooth. Note the reticulate ornamentation of the spores, similar to that of Oligonema schweinitzii and Trichia persimilis. D. Capillitial threads of Cornuvia serpula, branched and ornamented with rings. Scale and colours are approximate. Credit photos: Michel Poulain.
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pone-0062586-g006: Four different capillitial threads in Trichiida.A. Capillitial threads of Trichia varia: isolated threads sculptured with spiral bands, two very short ones are indicated by a black line. B. Capillitial threads of Arcyria obvelata, forming a network and sculptured with spines. C. Capillitial threads of Oligonema flavidum, short and in this case branched, smooth. Note the reticulate ornamentation of the spores, similar to that of Oligonema schweinitzii and Trichia persimilis. D. Capillitial threads of Cornuvia serpula, branched and ornamented with rings. Scale and colours are approximate. Credit photos: Michel Poulain.

Mentions: There is no general agreement on the delimitation of Arcyriidae and Trichiidae: they have been separated on the basis of the non-birefringence of the capillitium under polarized light [11], [44], a character discarded by some authors, e.g. Lado et al. [10]. Nonetheless, it is generally accepted that in Trichiidae the capillitium is mostly made of isolated threads sculptured with spiral bands (Fig. 6 A), while in Arcyriidae it is mostly net-forming and smooth or variously sculptured with warts, rings or spines, but not with clear spiral bands [10], [12] (Fig. 6 B). This classification is challenged by the genus Metatrichia, possessing a branching capillitium with spiral bands, which has been alternatively placed in Arcyriidae or in Trichiidae [10], [11], [12]. Species with capillitium made of isolated threads but without spiral bands, as Oligonema (Fig. 6 C) or with Arcyria-like rings, as Cornuvia (Fig. 6 D), have nevertheless been included in Trichiidae. Our phylogenetic results do not support the existing demarcation between these two families; instead we see the emergence of several clades: new clade 2, Arcyria, Perichaena and “Trichia and allied genera”. Their mutual relationships are not well-supported, except that Perichaena is robustly sister to “Trichia and allied genera”, which contradicts its current placement in Arcyriidae.


Two-gene phylogeny of bright-spored Myxomycetes (slime moulds, superorder Lucisporidia).

Fiore-Donno AM, Clissmann F, Meyer M, Schnittler M, Cavalier-Smith T - PLoS ONE (2013)

Four different capillitial threads in Trichiida.A. Capillitial threads of Trichia varia: isolated threads sculptured with spiral bands, two very short ones are indicated by a black line. B. Capillitial threads of Arcyria obvelata, forming a network and sculptured with spines. C. Capillitial threads of Oligonema flavidum, short and in this case branched, smooth. Note the reticulate ornamentation of the spores, similar to that of Oligonema schweinitzii and Trichia persimilis. D. Capillitial threads of Cornuvia serpula, branched and ornamented with rings. Scale and colours are approximate. Credit photos: Michel Poulain.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3646832&req=5

pone-0062586-g006: Four different capillitial threads in Trichiida.A. Capillitial threads of Trichia varia: isolated threads sculptured with spiral bands, two very short ones are indicated by a black line. B. Capillitial threads of Arcyria obvelata, forming a network and sculptured with spines. C. Capillitial threads of Oligonema flavidum, short and in this case branched, smooth. Note the reticulate ornamentation of the spores, similar to that of Oligonema schweinitzii and Trichia persimilis. D. Capillitial threads of Cornuvia serpula, branched and ornamented with rings. Scale and colours are approximate. Credit photos: Michel Poulain.
Mentions: There is no general agreement on the delimitation of Arcyriidae and Trichiidae: they have been separated on the basis of the non-birefringence of the capillitium under polarized light [11], [44], a character discarded by some authors, e.g. Lado et al. [10]. Nonetheless, it is generally accepted that in Trichiidae the capillitium is mostly made of isolated threads sculptured with spiral bands (Fig. 6 A), while in Arcyriidae it is mostly net-forming and smooth or variously sculptured with warts, rings or spines, but not with clear spiral bands [10], [12] (Fig. 6 B). This classification is challenged by the genus Metatrichia, possessing a branching capillitium with spiral bands, which has been alternatively placed in Arcyriidae or in Trichiidae [10], [11], [12]. Species with capillitium made of isolated threads but without spiral bands, as Oligonema (Fig. 6 C) or with Arcyria-like rings, as Cornuvia (Fig. 6 D), have nevertheless been included in Trichiidae. Our phylogenetic results do not support the existing demarcation between these two families; instead we see the emergence of several clades: new clade 2, Arcyria, Perichaena and “Trichia and allied genera”. Their mutual relationships are not well-supported, except that Perichaena is robustly sister to “Trichia and allied genera”, which contradicts its current placement in Arcyriidae.

Bottom Line: We discuss possible evolutionary pathways.Our study fills a gap in the phylogeny of Amoebozoa and provides an extensive SSU rRNA sequence reference database for environmental sampling and barcoding.We report a new group I intron insertion site for Myxomycetes in one Licea.

View Article: PubMed Central - PubMed

Affiliation: Zoology Department, University of Oxford, Oxford, United Kingdom. afiore-donno6@infomaniak.ch

ABSTRACT
Myxomycetes, or plasmodial slime-moulds, are one of the largest groups in phylum Amoebozoa. Nonetheless, only ∼10% are in the database for the small subunit (SSU) ribosomal RNA gene, the most widely used gene for phylogenetics and barcoding. Most sequences belong to dark-spored Myxomycetes (order Fuscisporida); the 318 species of superorder Lucisporidia (bright-spored) are represented by only eleven genuine sequences. To compensate for this, we provide 66 new sequences, 37 SSU rRNA and 29 elongation factor 1-alpha (EF-1α), for 82% of the genera of Lucisporidia. Phylogenetic analyses of single- and two-gene alignments produce congruent topologies and reveal both morphological characters that have been overemphasised and those that have been overlooked in past classifications. Both classical orders, Liceida and Trichiida, and several families and genera are para/polyphyletic; some previously unrecognised clades emerge. We discuss possible evolutionary pathways. Our study fills a gap in the phylogeny of Amoebozoa and provides an extensive SSU rRNA sequence reference database for environmental sampling and barcoding. We report a new group I intron insertion site for Myxomycetes in one Licea.

Show MeSH