Different fates of the chloroplast tufA gene following its transfer to the nucleus in green algae

Previous work suggested that the tufA gene, encoding protein synthesis elongation factor Tu, was transferred from the chloroplast to the nucleus within the green algal lineage giving rise to land plants. In this report we investigate the timing and mode of transfer by examining chloroplast and nuclear DNA from the three major classes of green algae, with emphasis on the class Charophyceae, the proposed sister group to land plants. Filter hybridizations reveal a chloroplast tufA gene in all Ulvophyceae and Chlorophyceae, and in some but not all Charophyceae. One charophycean alga, Coleochaete orbicularis, is shown to contain an intact but highly divergent chloroplast tufA gene, whose product is predicted to be nonfunctional in protein synthesis. We propose that a copy of the tufA gene was functionally transferred from the chloroplast to the nucleus early in the evolution of the Charophyceae, with chloroplast copies of varying function being retained in some but not all of the subsequently diverging lineages. This proposal is supported by the demonstration of multiple tufA-like sequences in Coleochaete nuclear DNA and in nuclear DNA from all other Charophyceae examined

Sensitivity of Antarctic Urospora penicilliformis (Ulotrichales, Chlorophyta) to ultraviolet radiation is life stage dependent

The sensitivity of different life stages of the eulittoral green alga Urospora penicilliformis (Roth) Aresch. to ultraviolet radiation (UVR) was examinedin the laboratory. Gametophytic filaments and propagules (zoospores and gametes) released from filaments were separately exposed to different fluence of radiation treatments consisting of PAR (P = 400700 nm), PAR + ultraviolet A (UVA) (PA, UVA = 320400 nm), and PAR + UVA + ultraviolet B (UVB) (PAB, UVB = 280320 nm). Photophysiological indices (ETRmax, Ek, and a) derived from rapid light curves were measured in controls, while photosynthetic efficiency and amount of DNA lesions in terms of cyclobutane pyrimidine dimers (CPDs) were measured after exposure to radiation treatments and after recovery in low PAR; pigments of propagules were quantified after exposure treatment only. The photosynthetic conversion efficiency (a) and photosynthetic capacity (rETRmax) were higher in gametophytes compared with the propagules. The propagules were slightly more sensitive to UVB-induced DNA damage; however, both life stages of the eulittoral inhabiting turf alga were not severely affected by the negative impacts of UVR. Exposure to a maximum of 8 h UVR caused mild effects on the photochemical efficiency of PSII and induced minimal DNA lesions in both the gametophytes and propagules. Pigment concentrations were not significantly different between PAR-exposed and PAR + UVRexposed propagules. Our data showed that U. penicilliformis from the Antarctic is ratherinsensitive to the applied UVR. This amphi-equatorial species possesses different protective mechanisms that can cope with high UVR in coldtemperatewaters of both hemispheres and in polar regions under conditions of increasing UVR as a consequence of further reduction of stratosphericozone

Further expansion of the alien seaweed Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procacini (Ulvophyceae, Bryopsidales) in the Eastern Mediterranean Sea

We are grateful to Andreas Antoniou (Dep. of Environment, Ministry of Agriculture, Rural Development & Environment, Cyprus) for his assistance in the preparation of the illustrations. We would also like to thank Dr. Sotiris Orfanidis (NAGREF – Fisheries Research Institute, Kavala, Greece) for his valuable advice and both the DFMR and HSR / HCMR Rhodes crew and George Hatiris for their help in samplings. Special thanks are due to Dinos Leonidou (SeaQuest Divers Cyprus) for accompanying the deep dive for sampling Caulerpa at Cavo Greco. We are grateful to the Total Foundation (Paris) for its funding support to this study within the framework of the project “Brown algal ecology and biodiversity in the eastern Mediterranean Sea” and to the MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland, funded by the Scottish Funding Council and contributing institutions; grant reference HR09011).Peer reviewedPublisher PD

Distribution of Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procaccini in the Mediterranean Sea

The Non-Indigenous Species (NIS) Caulerpa taxifolia var. distichophylla (Sonder) Verlaque, Huisman & Procaccini has been reported for the first time in the Mediterranean Sea along the coast of South Turkey. This NIS is actively expanding into the Eastern and Western Mediterranean Sea. In this paper, we present an overview of the current distribution of this alga in the Mediterranean Sea, based on relevant scientific publications, grey literature and personal observations. New records from the Sicilian coast (Italy) are also reported. Caulerpa taxifolia var. distichophylla was found over a wide range of environmental conditions (depth, light and substratum), suggesting a broad ecological plasticity of this alga which makes it a poten- tial threat for the Mediterranean benthic communities. In this respect, artificial structures, often linked to harbours and maritime traffic, seem to provide suitable habitats for this NIS. Since maritime traffic is intense in the Mediterranean Sea, further expansion of C. taxifolia var. distichophylla in this region is to be expected. For this reason, it is very important to build up an overview on the current distribution of the species and its possible pattern of colonisation in relation to environmental conditions, as well as in view of future climate change scenarios

New phylogenetic hypotheses for the core Chlorophyta based on chloroplast sequence data

Phylogenetic relationships in the green algal phylum Chlorophyta have long been subject to debate, especially at higher taxonomic ranks (order, class). The relationships among three traditionally defined and well-studied classes, Chlorophyceae, Trebouxiophyceae, and Ulvophyceae are of particular interest, as these groups are species-rich and ecologically important worldwide. Different phylogenetic hypotheses have been proposed over the past two decades and the monophyly of the individual classes has been disputed on occasion. Our study seeks to test these hypotheses by combining high throughput sequencing data from the chloroplast genome with increased taxon sampling. Our results suggest that while many of the deep relationships are still problematic to resolve, the classes Trebouxiophyceae and Ulvophyceae are likely not monophyletic as currently defined. Our results also support relationships among several trebouxiophycean taxa that were previously unresolved. Finally, we propose that the common term for the grouping of the three classes, “UTC clade,” be replaced with the term “core Chlorophyta” for the well-supported clade containing Chlorophyceae, taxa belonging to Ulvophyceae and Trebouxiophyceae, and the classes Chlorodendrophyceae and Pedinophyceae

Marine Biodiversity and Ecosystem Health of Ilhas Selvagens, Portugal

In September 2015, National Geographic's Pristine Seas project, in conjunction with the Instituto Universitário-Portugal, The Waitt Institute, the University of Western Australia, and partners conducted a comprehensive assessment of the rarely surveyed Ilhas Selvagens to explore the marine environment, especially the poorly understood deep sea and open ocean areas, and quantify the biodiversity of the nearshore marine environment

Flora en fauna geassocieerd met mosselpopulaties in de Oosterschelde en Voordelta in 2009

In de periode van 5 tot en met 25 augustus 2009 zijn er bemonsteringen uitgevoerd van hangcultuur mosselen, mosselpercelen en MZI’s. In totaal zijn er 30 monsters genomen in de Voordelta en de Oosterschelde. In deze studie zijn 65 exoten geïdentificeerd die in potentie zouden kunnen worden geïntroduceerd met de zuid-noordtransporten van de mosselen. Tevens zijn er monsters genomen van MZIinstallaties, de hangcultures en bodemmosselen in de Oosterschelde en de Voordelta. Van de 116 aangetroffen soorten in de monsters uit de Oosterschelde waren 12 soorten gekenmerkt als exoot. In de MZI’s, die een relatief korte tijd in de Oosterschelde hangen zijn er in absoluut getal niet minder, maar wel andere soorten exoten aangetroffen dan in de bodemcultuur