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Gromochytrium mamkaevae gen. & sp. nov. and two new orders: Gromochytriales and Mesochytriales (Chytridiomycetes).

Karpov SA, Kobseva AA, Mamkaeva MA, Mamkaeva KA, Mikhailov KV, Mirzaeva GS, Aleoshin VV - Persoonia (2014)

Bottom Line: During the last decade several new orders were established in the class Chytridiomycetes on the basis of zoospore ultrastructure and molecular phylogeny.Detailed investigation revealed that the zoospore ultrastructure of this strain has unique characters not found in any order of Chytridiomycetes: posterior ribosomal core unbounded by the endoplasmic reticulum and detached from the nucleus or microbody-lipid complex, and kinetosome composed of microtubular doublets.An isolated phylogenetic position of x-51 is further confirmed by the analysis of 18S and 28S rRNA sequences, and motivates the description of a new genus and species Gromochytrium mamkaevae.

View Article: PubMed Central - PubMed

Affiliation: Zoological Institute, Russian Academy of Sciences, St. Petersburg 198904, Russian Federation; ; Biological Faculty, St. Petersburg State University, St. Petersburg 198904, Russian Federation.

ABSTRACT
During the last decade several new orders were established in the class Chytridiomycetes on the basis of zoospore ultrastructure and molecular phylogeny. Here we present the ultrastructure and molecular phylogeny of strain x-51 CALU - a parasite of the alga Tribonema gayanum, originally described as Rhizophydium sp. based on light microscopy. Detailed investigation revealed that the zoospore ultrastructure of this strain has unique characters not found in any order of Chytridiomycetes: posterior ribosomal core unbounded by the endoplasmic reticulum and detached from the nucleus or microbody-lipid complex, and kinetosome composed of microtubular doublets. An isolated phylogenetic position of x-51 is further confirmed by the analysis of 18S and 28S rRNA sequences, and motivates the description of a new genus and species Gromochytrium mamkaevae. The sister position of G. mamkaevae branch relative to Mesochytrium and a cluster of environmental sequences, as well as the ultrastructural differences between Gromochytrium and Mesochytrium zoospores prompted us to establish two new orders: Gromochytriales and Mesochytriales.

No MeSH data available.


Related in: MedlinePlus

General ultrastructure of Gromochytrium mamkaevae (x-51 CALU) zoospore. — a. General disposition of nucleus and other organelles at LS; b. tangential section of fenestrated cisterna crossed by anterior microtubular root; c. pseudopodia at cell anterior; d, e. two consecutive sections of the kinetid. — Abbreviations: ar = anterior microtubular root; c = centriole; d = kinetosome diaphragm; db = dense bodies; fc = fenestrated cisterna; k = kinetosome; l = lipid globule; m = mitochondrion; mb = microbody; n = nucleus; ps = pseudopodia; rc = ribosomal core; tf = transitional fibers (props); vz = vesicular zone. — Scale bar on E: a = 300 nm; b, c = 400 nm; d, e = 200 nm.
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Figure 3: General ultrastructure of Gromochytrium mamkaevae (x-51 CALU) zoospore. — a. General disposition of nucleus and other organelles at LS; b. tangential section of fenestrated cisterna crossed by anterior microtubular root; c. pseudopodia at cell anterior; d, e. two consecutive sections of the kinetid. — Abbreviations: ar = anterior microtubular root; c = centriole; d = kinetosome diaphragm; db = dense bodies; fc = fenestrated cisterna; k = kinetosome; l = lipid globule; m = mitochondrion; mb = microbody; n = nucleus; ps = pseudopodia; rc = ribosomal core; tf = transitional fibers (props); vz = vesicular zone. — Scale bar on E: a = 300 nm; b, c = 400 nm; d, e = 200 nm.

Mentions: The spherical zoospore has a posterior flagellum and sometimes produces short anterior filopodia (Fig. 3c). A core of aggregated ribosomes is located in the posterior part of the cell. The ribosomal aggregation is relatively small and does not have surrounding endoplasmic reticulum (Fig. 3, 4). The ribosomes fill the space between the flagellar base and the nucleus and have no connection with nucleus, mitochondria or other membrane bounded organelles.


Gromochytrium mamkaevae gen. & sp. nov. and two new orders: Gromochytriales and Mesochytriales (Chytridiomycetes).

Karpov SA, Kobseva AA, Mamkaeva MA, Mamkaeva KA, Mikhailov KV, Mirzaeva GS, Aleoshin VV - Persoonia (2014)

General ultrastructure of Gromochytrium mamkaevae (x-51 CALU) zoospore. — a. General disposition of nucleus and other organelles at LS; b. tangential section of fenestrated cisterna crossed by anterior microtubular root; c. pseudopodia at cell anterior; d, e. two consecutive sections of the kinetid. — Abbreviations: ar = anterior microtubular root; c = centriole; d = kinetosome diaphragm; db = dense bodies; fc = fenestrated cisterna; k = kinetosome; l = lipid globule; m = mitochondrion; mb = microbody; n = nucleus; ps = pseudopodia; rc = ribosomal core; tf = transitional fibers (props); vz = vesicular zone. — Scale bar on E: a = 300 nm; b, c = 400 nm; d, e = 200 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150072&req=5

Figure 3: General ultrastructure of Gromochytrium mamkaevae (x-51 CALU) zoospore. — a. General disposition of nucleus and other organelles at LS; b. tangential section of fenestrated cisterna crossed by anterior microtubular root; c. pseudopodia at cell anterior; d, e. two consecutive sections of the kinetid. — Abbreviations: ar = anterior microtubular root; c = centriole; d = kinetosome diaphragm; db = dense bodies; fc = fenestrated cisterna; k = kinetosome; l = lipid globule; m = mitochondrion; mb = microbody; n = nucleus; ps = pseudopodia; rc = ribosomal core; tf = transitional fibers (props); vz = vesicular zone. — Scale bar on E: a = 300 nm; b, c = 400 nm; d, e = 200 nm.
Mentions: The spherical zoospore has a posterior flagellum and sometimes produces short anterior filopodia (Fig. 3c). A core of aggregated ribosomes is located in the posterior part of the cell. The ribosomal aggregation is relatively small and does not have surrounding endoplasmic reticulum (Fig. 3, 4). The ribosomes fill the space between the flagellar base and the nucleus and have no connection with nucleus, mitochondria or other membrane bounded organelles.

Bottom Line: During the last decade several new orders were established in the class Chytridiomycetes on the basis of zoospore ultrastructure and molecular phylogeny.Detailed investigation revealed that the zoospore ultrastructure of this strain has unique characters not found in any order of Chytridiomycetes: posterior ribosomal core unbounded by the endoplasmic reticulum and detached from the nucleus or microbody-lipid complex, and kinetosome composed of microtubular doublets.An isolated phylogenetic position of x-51 is further confirmed by the analysis of 18S and 28S rRNA sequences, and motivates the description of a new genus and species Gromochytrium mamkaevae.

View Article: PubMed Central - PubMed

Affiliation: Zoological Institute, Russian Academy of Sciences, St. Petersburg 198904, Russian Federation; ; Biological Faculty, St. Petersburg State University, St. Petersburg 198904, Russian Federation.

ABSTRACT
During the last decade several new orders were established in the class Chytridiomycetes on the basis of zoospore ultrastructure and molecular phylogeny. Here we present the ultrastructure and molecular phylogeny of strain x-51 CALU - a parasite of the alga Tribonema gayanum, originally described as Rhizophydium sp. based on light microscopy. Detailed investigation revealed that the zoospore ultrastructure of this strain has unique characters not found in any order of Chytridiomycetes: posterior ribosomal core unbounded by the endoplasmic reticulum and detached from the nucleus or microbody-lipid complex, and kinetosome composed of microtubular doublets. An isolated phylogenetic position of x-51 is further confirmed by the analysis of 18S and 28S rRNA sequences, and motivates the description of a new genus and species Gromochytrium mamkaevae. The sister position of G. mamkaevae branch relative to Mesochytrium and a cluster of environmental sequences, as well as the ultrastructural differences between Gromochytrium and Mesochytrium zoospores prompted us to establish two new orders: Gromochytriales and Mesochytriales.

No MeSH data available.


Related in: MedlinePlus