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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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Related in: MedlinePlus

Spore-like bodies.A. Vertical section of the stalk and the base of the sporotheca of Hemitrichia calyculata, showing the stalk filled with spore-like bodies. Those are larger and clearer than the spores in the sporotheca above, without clear demarcation. B. Vertical section of the stalk and the base of the sporotheca of Trichia decipiens, showing the stalk filled with spore-like bodies and few capillitial filaments. C. Greater magnification of the spore-like bodies of Trichia decipiens. Scale and colours are approximate. Credit photos: Michel Poulain.
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pone-0062586-g007: Spore-like bodies.A. Vertical section of the stalk and the base of the sporotheca of Hemitrichia calyculata, showing the stalk filled with spore-like bodies. Those are larger and clearer than the spores in the sporotheca above, without clear demarcation. B. Vertical section of the stalk and the base of the sporotheca of Trichia decipiens, showing the stalk filled with spore-like bodies and few capillitial filaments. C. Greater magnification of the spore-like bodies of Trichia decipiens. Scale and colours are approximate. Credit photos: Michel Poulain.

Mentions: A previously unrecognised clade associates two Hemitrichia species, H. abietina and H. calyculata, with Trichia decipiens (although only well-supported in Bayesian analyses, Fig. 1∶0.99/−, Fig. 2∶1.0/0.59). In spite of their presently being in different genera, there is a striking characteristic shared by these three species: the stalk is filled with “spore-like bodies” (Fig. 7). These structures are formed during sporophore development by cleavage of the cytoplasm: the nuclei in the sporotheca will form spores, the ones in the stalk will become spore-like bodies [45]. The latter are larger than spores, multinucleate and highly vacuolated, and densely packed in the stalk [45] (Fig. 7). Spore-like bodies are characteristic of Arcyria and are also found in Licea operculata[29]. Establishing a new family for this clade will probably be appropriate but is premature before the type species Hemitrichia clavata is investigated, as well as sessile specimens of Hemitrichia.


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)

Spore-like bodies.A. Vertical section of the stalk and the base of the sporotheca of Hemitrichia calyculata, showing the stalk filled with spore-like bodies. Those are larger and clearer than the spores in the sporotheca above, without clear demarcation. B. Vertical section of the stalk and the base of the sporotheca of Trichia decipiens, showing the stalk filled with spore-like bodies and few capillitial filaments. C. Greater magnification of the spore-like bodies of Trichia decipiens. Scale and colours are approximate. Credit photos: Michel Poulain.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646832&req=5

pone-0062586-g007: Spore-like bodies.A. Vertical section of the stalk and the base of the sporotheca of Hemitrichia calyculata, showing the stalk filled with spore-like bodies. Those are larger and clearer than the spores in the sporotheca above, without clear demarcation. B. Vertical section of the stalk and the base of the sporotheca of Trichia decipiens, showing the stalk filled with spore-like bodies and few capillitial filaments. C. Greater magnification of the spore-like bodies of Trichia decipiens. Scale and colours are approximate. Credit photos: Michel Poulain.
Mentions: A previously unrecognised clade associates two Hemitrichia species, H. abietina and H. calyculata, with Trichia decipiens (although only well-supported in Bayesian analyses, Fig. 1∶0.99/−, Fig. 2∶1.0/0.59). In spite of their presently being in different genera, there is a striking characteristic shared by these three species: the stalk is filled with “spore-like bodies” (Fig. 7). These structures are formed during sporophore development by cleavage of the cytoplasm: the nuclei in the sporotheca will form spores, the ones in the stalk will become spore-like bodies [45]. The latter are larger than spores, multinucleate and highly vacuolated, and densely packed in the stalk [45] (Fig. 7). Spore-like bodies are characteristic of Arcyria and are also found in Licea operculata[29]. Establishing a new family for this clade will probably be appropriate but is premature before the type species Hemitrichia clavata is investigated, as well as sessile specimens of Hemitrichia.

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
Related in: MedlinePlus