February 2021 archive

Portimine, a recently identified cyclic imine produced by the dinoflagellate Vulcanodinium rugosum, has been described as a potent apoptotic agent in contrast to most of the cyclic imines that are well-known to be neurological toxins. As apoptosis can be a consequence of a high level of DNA lesions, we investigated the responses of portimine on several endpoints aimed at detecting DNA damage in the hepatic cell line HepaRG. Portimine induced phosphorylation of H2AX, which could possibly be…

Corals of the family Acroporidae are key structural components of reefs that support the most diverse marine ecosystems. Due to increasing anthropogenic stresses, coral reefs are in decline. Along the coast of Okinawa, Japan, three different color morphs of Acropora tenuis have been recognized for decades. These include brown (N morph), yellow green (G), and purple (P) forms. The tips of axial polyps of each morph exhibit specific fluorescence spectra. This attribute is inherited asexually, and…

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Protistology and Cell Biology at the Marine Arago Laboratory of Banyuls-sur-Mer (1961-2000): Personal Recollections.
Protist. 2021 Jan 28;172(1):125792
Authors: Soyer-Gobillard MO
Abstract
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The history of protistology and the introduction of modern methods of unicell observations is described in a large maritime laboratory over a period of forty years by the initiator of this new team. The development of this team and the doctoral theses developed there are described as well as the major discoveries made. The Arago Laboratory, which was then in 1960 a field laboratory mainly devoted to the collection of biological material, becomes a research laboratory specializing in the study of…

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Is the dinoflagellate Amoebophrya really missing a mtDNA?
Mol Biol Evol. 2021 Feb 10;:
Authors: Kayal E, Smith DR
Abstract
Mitochondrial DNA (mtDNA) is a universal hallmark of aerob…

Mitochondrial DNA (mtDNA) is a universal hallmark of aerobic eukaryotes. That is why the recent suggestion by John et al. (2019) that the aerobic dinoflagellate Amoebophrya sp. strain AT5 (Syndiniales) lacks mtDNA was so remarkable. Here, by reanalysing recently published genomic and transcriptomic data from three Amoebophrya strains, we provide evidence of a cryptic, highly reduced mtDNA in this clade. More work is needed before one can definitively say if Amoebophrya has or does not have a…

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Adaptive responses of free-living and symbiotic microalgae to simulated future ocean conditions.
Glob Chang Biol. 2021 Feb 05;:
Authors: Chan WY, Oakeshott JG, Buerger P, Edwards OR, van Oppen MJH
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Genomic adaptations to an endolithic lifestyle in the coral-associated alga Ostreobium.
Curr Biol. 2021 Feb 02;:
Authors: Iha C, Dougan KE, Varela JA, Avila V, Jackson CJ, Bogaert KA, Chen Y, Judd …

The green alga Ostreobium is an important coral holobiont member, playing key roles in skeletal decalcification and providing photosynthate to bleached corals that have lost their dinoflagellate endosymbionts. Ostreobium lives in the coral’s skeleton, a low-light environment with variable pH and O(2) availability. We present the Ostreobium nuclear genome and a metatranscriptomic analysis of healthy and bleached corals to improve our understanding of Ostreobium’s adaptations to its extreme…

Marine microalgae are a diverse group of microscopic eukaryotic and prokaryotic organisms capable of photosynthesis. They are important primary producers and carbon sinks but their physiology and persistence are severely affected by global climate change. Powerful experimental evolution technologies are being used to examine the potential of microalgae to respond adaptively to current and predicted future conditions, as well as to develop resources to facilitate species conservation and…