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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

Pseudoaethalium of Dictydiaethalium plumbeum.A. Pseudoaethalium seen from above. B. Vertical section with the spore mass partially blown away, showing the renmants of the peridia as hexagonal caps on the upper surface and vertical fine threads connecting them to the base of the fructification. Scales and colours are approximate. Credit photos: Michel Poulain.
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pone-0062586-g004: Pseudoaethalium of Dictydiaethalium plumbeum.A. Pseudoaethalium seen from above. B. Vertical section with the spore mass partially blown away, showing the renmants of the peridia as hexagonal caps on the upper surface and vertical fine threads connecting them to the base of the fructification. Scales and colours are approximate. Credit photos: Michel Poulain.

Mentions: The term “pseudocapillitium” refers to filaments found in the aethaloid fructifications in Reticulariidae and Dictydiaethaliidae, regarded as the remnant of sporangial walls. From our results and from a critical analysis of morphological and ultrastructural past observations, it appears that distinct processes are jumbled under the name “capillitium”, while the term “pseudocapillitium” may be redundant. In Reticulariidae, very different types of pseudocapillitium are found: in Lycogala, it is composed of hollow, branched tubes arising from the inner surface of the peridium [39] (Fig. 3 D); in Reticularia, it is a tridimensional network of more or less flattened structures. In the non-related Dictydiaethaliidae, the peridium persists at the top of the tightly compressed sporangia as a hexagonal plate, while the peridia between sporangia remain only as fine threads connecting the angles of the plate to the base of the pseudoaethalium (Fig. 4 A, B). TEM studies on capillitial ontogeny are needed to assess to what degree the structures referred to as pseudocapillitium in Reticularia, Lycogala and Dictydiaethaliidae are homologous, and how they are related with the different types of “true” capillitium.


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)

Pseudoaethalium of Dictydiaethalium plumbeum.A. Pseudoaethalium seen from above. B. Vertical section with the spore mass partially blown away, showing the renmants of the peridia as hexagonal caps on the upper surface and vertical fine threads connecting them to the base of the fructification. Scales 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-g004: Pseudoaethalium of Dictydiaethalium plumbeum.A. Pseudoaethalium seen from above. B. Vertical section with the spore mass partially blown away, showing the renmants of the peridia as hexagonal caps on the upper surface and vertical fine threads connecting them to the base of the fructification. Scales and colours are approximate. Credit photos: Michel Poulain.
Mentions: The term “pseudocapillitium” refers to filaments found in the aethaloid fructifications in Reticulariidae and Dictydiaethaliidae, regarded as the remnant of sporangial walls. From our results and from a critical analysis of morphological and ultrastructural past observations, it appears that distinct processes are jumbled under the name “capillitium”, while the term “pseudocapillitium” may be redundant. In Reticulariidae, very different types of pseudocapillitium are found: in Lycogala, it is composed of hollow, branched tubes arising from the inner surface of the peridium [39] (Fig. 3 D); in Reticularia, it is a tridimensional network of more or less flattened structures. In the non-related Dictydiaethaliidae, the peridium persists at the top of the tightly compressed sporangia as a hexagonal plate, while the peridia between sporangia remain only as fine threads connecting the angles of the plate to the base of the pseudoaethalium (Fig. 4 A, B). TEM studies on capillitial ontogeny are needed to assess to what degree the structures referred to as pseudocapillitium in Reticularia, Lycogala and Dictydiaethaliidae are homologous, and how they are related with the different types of “true” capillitium.

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