Aurearenophyceae classis nova, a New Class of Heterokontophyta Based on a New Marine Unicellular Alga Aurearenacruciata gen. et sp. nov. Inhabiting Sandy Beaches

Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan.
Protist (Impact Factor: 3.05). 08/2008; 159(3):435-57. DOI: 10.1016/j.protis.2007.12.003
Source: PubMed


A new heterokontophyte alga, Aurearena cruciata gen. et sp. nov., was isolated from sandy beaches in Japan. Isolates were characterized by light and electron microscopy, spectroscopy of pigment composition, and molecular phylogenetic analyses using 18S rDNA and rbcL. The alga usually possessed a cell wall but also retained two heterokont flagella beneath the cell wall. Each walled cell first produced only a single flagellate cell that subsequently divided into two flagellate cells. Electron-opaque vesicles, possibly associated with cell wall formation, were observed beneath the cell membrane. The chloroplast consisted of two compartments, each enclosed by a chloroplast envelope and the inner membrane of the chloroplast endoplasmic reticulum; these two compartments were surrounded by a common outer membrane of chloroplast endoplasmic reticulum. Molecular phylogenetic trees suggested that this alga was a new and independent member of the clade that included the Phaeophyceae and Xanthophyceae (PX clade). A new class, Aurearenophyceae classis nova was proposed for A. cruciata.

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    • "Our ML analysis strongly supports including Schizocladia in Phaeophyceae, but confirms that Phaeothamnion and Stichogloea (here treated together with Phaeoschizochlamys as Phaeothamniales sensu stricto) are much more closely related to the unicellular brownish alga Aurearena than to multicellular Phaeophyceae, as Kai et al. (2008) first showed. We therefore establish this new class for the robust clade (BS 81%) comprising Aurearenales (Kai et al. 2008) and Phaeothamniales sensu stricto (Fig. 15). Several differences between Aurearena and Phaeothamniales are simply differential losses of ancestral characters for Fucistia (e.g. "
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    European Journal of Protistology 12/2012; 49(3). DOI:10.1016/j.ejop.2012.09.002 · 2.80 Impact Factor
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    • "Two transitional plates have been reported in Coscinodiscus and Chaetoceros (Jensen et al. 2003) and are evident in electron micrographs of Lithodesmium (Manton and von Stosch 1966, fig. 12), but their absence in the two diatoms studied here, together with the much more diffuse appearance of the upper plate in the three diatoms in which it has been reported, compared to Bolidomonas (Guillou et al. 1999), Pelagomonas (Andersen et al. 1993) or other heterokonts (Kawai et al. 2003; Kai et al. 2008; Kim et al. 2010) leads us to suggest that homology should not be assumed. "
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    Protoplasma 11/2012; 250(4). DOI:10.1007/s00709-012-0465-8 · 2.65 Impact Factor
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    • "Although there is no evidence for the Glaucocystophyta, it is likely that they also lack xanthophylls cycle because they, like the three higher taxa lacking xanthophyll cycles, have phycobilins as major light-harvesting pigments. Evidence as to the occurrence of xanthophyll cycles is also lacking for several algal higher taxa lacking light-harvesting phycobilins, e.g. the phylum Chlorarachniophyta, the apicomplexans (Alveolata) whose only known extant photosynthetic member is Chromera velia (Janouškovec et al. 2010, Moore et al. 2008) and the classes Pinguiophyceae and Synchromophyceae in the phylum Heterokonotophyta (Kai et al. 2008). It is also known that the green (ulvophycean) marine macroalga Chlorodesmis fastigiata lacks xanthophyll cycle activity despite living in a high irradiance environment (Franklin et al. 1996, Franklin and Larkum 1997). "
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    Physiologia Plantarum 03/2011; 142(1):87-104. DOI:10.1111/j.1399-3054.2011.01465.x · 3.14 Impact Factor
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