Search

The generalized use of molecular identification tools indicated that multispecific green tides are more common than previously thought. Temporal successions between bloom-forming species on a seasonal basis were also revealed in different cold temperate estuaries, suggesting a key role of photoperiod and temperature controlling bloom development and composition. According to the Intergovernmental Panel on Climate Change, water temperatures are predicted to increase around 4°C by 2100 in Ireland, especially during late spring coinciding with early green tide development. Considering current and predicted temperatures, and photoperiods during bloom development, different eco-physiological experiments were developed. These experiments indicated that the growth of Ulva lacinulata was controlled by temperature, while U. compressa was unresponsive to the photoperiod and temperatures assayed. Considering a scenario of global warming for Irish waters, an earlier development of bloom is expected in the case of U. lacinulata. This could have significant consequences for biomass balance in Irish estuaries and the maximum accumulated biomass during peak bloom. The observed seasonal patterns and experiments also indicated that U. compressa may facilitate U. lacinulata development. When both species were co-cultivated, the culture performance showed intermediate responses to experimental treatments in comparison with monospecific cultures of both species.

International audience; A vast diversity of types of life cycles exists in nature, and several theories have been advanced to explain how this diversity has evolved and how each type of life cycle is retained over evolutionary time. Here, we exploited the diversity of life cycles and reproductive traits of the brown algae (Phaeophyceae) to test several hypotheses on the evolution of life cycles. We investigated the evolutionary dynamics of four life-history traits: life cycle, sexual system, level of gamete dimorphism and gamete parthenogenetic capacity. We assigned states to up to 77 representative species of the taxonomic diversity of the brown algal group, in a multi-gene phylogeny. We used maximum likelihood and Bayesian analyses of correlated evolution, while taking the phylogeny into account, to test for correlations between traits, and to investigate the chronological sequence of trait acquisition. Our analyses are consistent with the prediction that diploid growth evolves when sexual reproduction is preferred over asexual reproduction, possibly because it allows the complementation of deleterious mutations. We also found that haploid sex determination is ancestral in relation to diploid sex determination. However, our results could not address whether increased zygotic and diploid growth are associated with increased sexual dimorphism. Our analyses suggest that in the brown algae, isogamous species evolved from anisogamous ancestors, contrary to the commonly reported pattern where evolution proceeds from isogamy to anisogamy.

Manawatāwhi/Three Kings Islands lie to the north of the North Island of New Zealand. Manawatāwhi is part of the rohe (territory) of Ngāti Kuri, with the islands having spiritual, cultural, political and customary significance. This group of small islands has one of the most pristine coastlines in New Zealand, with no human-mediated impacts from current land use, no permanent anchorage points, and landing on the islands is prohibited. The islands harbour a rich marine biota with a number of endemic species. A recent collection trip and molecular genetic studies using the rbcL marker revealed the presence of three entities of the genus Ulva L. (Ulvales, Chlorophyta) on the islands. One of these we describe herein as Ulva piritoka Ngāti Kuri, Heesch & W.A.Nelson, sp. nov. While it is genetically close to U. adhaerens Matsumoto & Shimada from Japan, differences in morphology, habitat and rbcL gene region, including the presence of a large group II intron in U. adhaerens, which was lacking in the Manawatāwhi specimen, led us to conclude U. piritoka sp. nov. belongs to a distinct species. We also confirmed the presence of Ulva compressa L. and Ulva rigida C.Agardh, both of which, although present on the New Zealand mainland, were originally described from Europe and are considered introductions to the New Zealand archipelago. These are the first reported marine non-indigenous species (NIS) recorded from Manawatāwhi/Three Kings Islands, and the implications of their presence are discussed.

International audience; In the study of the evolution of biological complexity, a reliable phylogenetic framework is needed. Many attempts have been made to resolve phylogenetic relationships between higher groups (i.e., interordinal) of brown algae (Phaeophyceae) based on molecular evidence, but most of these relationships remain unclear. Analyses based on small multi-gene data (including chloroplast, mitochondrial and nuclear sequences) have yielded inconclusive and sometimes contradictory results. To address this problem, we have analyzed 32 nuclear proteincoding sequences in 39 Phaeophycean species belonging to eight orders. The resulting nuclear-based phylogenomic trees provide virtually full support for the phylogenetic relationships within the studied taxa, with few exceptions. The relationships largely confirm phylogenetic trees based on nuclear, chloroplast and mitochondrial sequences, except for the placement of the Sphacelariales with weak bootstrap support. Our study indicates that nuclear protein-coding sequences provide significant support to conclusively resolve phylogenetic relationships among Phaeophyceae, and may be a powerful approach to fully resolve interordinal relationships with increased taxon sampling.

Seaweeds are increasingly used in European cuisine. Until the recent use of molecular techniques, species identification was solely based on morphology which cannot easily discriminate morphologically simple but phenotypically plastic taxa such as the green algal genus Ulva. For example, current taxonomic protocol effectively reassigned the previously known European 'Ulva lactuca L.' under the name Ulva fenestrata Postels & Ruprecht. Also, the presumptive Ulva lactuca approved by the Institute for Reference Materials and Measurements (IRMM, Joint Research Center, European Commission) as Certified Reference Material (CRM) for analytical quality assurance was genetically identified as U. rigida C.Agardh. It is very likely that different Ulva species under various names have been consumed as food not only in Europe, but also worldwide. In this regard, when chemical composition and nutritional quality of different seaweed species meet a set of food standard criteria, and food safety hazards are mitigated, they should be endorsed for consumption. In the case of Ulva, we propose that different bladed and tubular species should generally be accepted for food consumption in Europe.

Two morphologically similar digitate kelp species, Laminaria digitata and Hedophyllum nigripes, co-occur along a shallow sublittoral depth gradient in the Arctic but, in contrast to L. digitata, very few ecophysiological data exist for H. nigripes. We investigated growth, survival, photosynthetic characteristics and carbon:nitrogen ratios of juvenile sporophytes, and recruitment and survival of gametophytes in genetically verified Arctic isolates of both species along temperature gradients (0–25 °C) over 14 days. Laminaria digitata gametophytes survived 23–24 °C, while sporophytes survived 21–22 °C. Hedophyllum nigripes had lower temperature affinities. Gametophytes survived 19–21 °C, while sporophytes survived 18 °C. Male gametophytes were more heat-tolerant than female gametophytes in both species. The pronounced cold adaption of H. nigripes compared to L. digitata also became apparent in different sporophyte growth optima (L. digitata: 15 °C; H. nigripes: 10 °C) and gametogenesis optima (L. digitata: 5–15 °C; H. nigripes: 0–10 °C). Higher carbon:nitrogen ratios in H. nigripes suggest an adaptation to nutrient poor Arctic conditions. The overall temperature performance of H. nigripes possibly restricts the species to Arctic–Sub-Arctic regions, while Arctic L. digitata behaved similarly to cold-temperate populations. Our data suggest that a future increase in seawater temperatures may hamper the success of H. nigripes and favour L. digitata in Arctic environments.

In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro- and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified.; Results: The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU.; Conclusion: This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.; © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

In-depth metabolic profiling, also termed metabolomics, provides detailed information about the biochemical phenotype of an organism. Besides improving our understanding of biochemical processes, metabolomics is used for environmental monitoring, natural product discovery, or even chemotaxonomy, among others. However, for marine macroalgae, comparative large-scale metabolomics studies are lacking, even though seaweeds belong to the most important aquatic primary producers. In this study, we present via a broad scale systematic metabolomics survey 391 metabolites from 21 seaweeds species, representing brown, red and green algae. We demonstrate clear differences in metabolite composition of these seaweeds, reflecting their taxonomic classification. We highlight these differences for amino acid, amino acid derivative and peptide metabolites, energy and carbohydrate metabolites, for lipid, fatty acid and sterol metabolites and for secondary metabolites, including selected metabolic pathways such as the urea cycle, the citrate cycle and the glyconeogenesis/glycolysis, besides others. Additionally, we link selected seaweed biochemical properties to potential pharmaceutical and nutraceutical applications.

International audience; Marine-freshwater and freshwater-marine transitions have been key events in the evolution of life, and most major groups of organisms have independently undergone such events at least once in their history. Here we first compile an inventory of bidirectional freshwater and marine transitions in multicellular photosynthetic eukaryotes. While green and red algae have mastered multiple transitions in both directions, brown algae have colonized fresh water on a maximum of six known occasions, and angiosperms have made the transition to marine environments only two or three times. Next we review the early evolutionary events leading to the colonization of current habitats. It is commonly assumed that the conquest of land proceeded in a sequence from marine to freshwater habitats. However, recent evidence suggests that early photosynthetic eukaryotes may have arisen in subaerial or freshwater environments and only later colonized marine environments as hypersaline oceans were diluted to the contemporary level. Although this hypothesis remains speculative, it is important to keep these alternative scenarios in mind when interpreting the current habitat distribution of plants and algae. Finally we discuss the roles of structural and functional adaptations of the cell wall, reactive oxygen species scavengers, osmoregulation, and reproduction. These are central for acclimatization to freshwater or to marine environments. We observe that successful transitions appear to have occurred more frequently in morphologically simple forms and conclude that, in addition to physiological studies of euryhaline species, comparative studies of closely related species fully adapted to one or the other environment are necessary to better understand the adaptive processes.

The brown algal genus Cladostephus (Sphacelariales) is found worldwide in temperate regions. Two species are considered endemic to South America (C. antarcticus Kützing and C. hariotii Sauvageau), whilst specimens from the rest of the world are usually attributed to a third, cosmopolitan species, C. spongiosus (Hudson) C.Agardh. However, comparisons of organellar (plastid rbcL and psbC, mitochondrial COI-5P) and nuclear (ITS nrDNA) markers for samples collected throughout the geographic range of C. spongiosus suggest that two genetic entities are treated under this name, which correspond to previously recognized morphological entities. Specimens with ‘spongiose’ morphology (C. spongiosus s.s.) were found to be limited to the Atlantic coast of Western Europe. The entity showing ‘verticillate’ morphology (‘C. verticillatus’) emerged as the cosmopolitan species: specimens were found on the Atlantic coasts of western Europe and the USA, in the Mediterranean, in New Zealand, Australia and on the Pacific coast of Mexico. Since the name C. verticillatus (Lightfoot) Lyngbye is illegitimate, this entity is herein referred to as C. hirsutus (L.) Boudouresque & M.Perret. A third genetic entity was only encountered in the southern hemisphere, i.e. in New Zealand, Australia, southern Chile and Falkland Islands. Comparisons with descriptions and images of type specimens suggest that this southern entity conforms most closely to the description of Cladostephus australis Kützing, nom. illeg., and it is herein renamed as Cladostephus kuetzingii Heesch, Rindi & W.A.Nelson.

The red seaweed Agarophyton vermiculophyllum is an invasive species native to the north-west Pacific, which has proliferated in temperate estuaries of Europe, North America and Africa. Combining molecular identification tools, historical satellite imagery and one-year seasonal monitoring of biomass and environmental conditions, the presence of A. vermiculophyllum was confirmed, and the invasion was assessed and reconstructed. The analysis of satellite imagery identified the first bloom in 2014 and revealed that A. vermiculophyllum is capable of thriving in areas, where native bloom-forming species cannot, increasing the size of blooms (ca. 10%). The high biomass found during the peak bloom (>2 kg m−2) and the observation of anoxic events indicated deleterious effects. The monitoring of environmental conditions and biomass variability suggests an essential role of light, temperature and phosphorous in bloom development. The introduction of this species could be considered a threat for local biodiversity and ecosystem functioning in a global change context.

Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga Vertebrata lanosa collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R2 ≥ 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 μg/mL and limits of quantification (LOQ) lower than 0.12 μg/mL. Subsequently, the method was applied to determine the bromophenol content in Vertebrata lanosa samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against Staphylococcus aureus and Escherichia coli bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.

The Norwegian seaweed industry is expanding and there is a need for accurate estimates of protein content of seaweed species from Norwegian waters. A solid method to calculate protein content is through the sum of the proteomic amino acids; however, it can be expensive and beyond the capacities of many laboratories. The most commonly used method to quantify protein is based on the assessment of crude protein from overall nitrogen content, using the traditional nitrogen-to-protein conversion factor of 6.25. However, this approach can be inaccurate when applied to seaweeds, often resulting in an overestimation of their protein content. Specific nitrogen-to-protein conversion factors, calculated from amino acid composition and total nitrogen, give a more reliable protein quantification in seaweeds. However, no such factors are available for species from Norwegian waters. This study was designed to characterize the amino acid composition of 21 seaweed species from Norwegian waters and use the amino acid data to estimate protein contents of the seaweeds. Crude protein analysis (nitrogen × 6.25) was performed and resulted in overestimation (18–44 %) of the protein content compared to the sum of proteomic amino acids. Specific nitrogen-to-protein conversion factors, calculated for each species, ranged from 3.53 ± 0.1 to 5.13 ± 0.1. This study provides nutritional data on Norwegian seaweeds, covering a relatively wide range of species. Moreover, it is the first study to assess nitrogen-to-protein conversion factors on such species.

SUMMARY Genetic diversity of native and introduced populations of Ulva pertusa (Ulvales, Chlorophyta) was examined using genetic markers of chloroplast, mitochondria and nuclear non-coding region sequences. In the preliminary investigations to genetically identify the species for further analyses, U. pertusa was found only from temperate coasts of the more extensive collection sites including tropical coasts suggesting that it is a temperate species and basically not distributed in tropical regions. For chloroplast and mitochondrial sequences, repeating patterns of short tandem repeat sequences and nucleotide substitutions were used to recognize the haplotypes (genetic types). A total of 48 haplotypes based on combinations of chloroplast and mitochondrial haplotypes were recognized in the 244 specimens collected in the presumptive native range (Northeast Asia) and introduced populations (North America, Australia, New Zealand, Chile and Europe). Among them, 46 haplotypes (H1–H8 and H11–H48) were recognized in Northeast Asia, whereas only 1–5 haplotypes were recognized in the other areas. Nuclear microsatellite sequences were also analyzed. The lengths of the PCR products including the nuclear microsatellite region of 234 specimens were determined, and a total of 17 genotypes were recognized. Among them, 14 genotypes were found in Northeast Asia, whereas 1–7 genotypes were recognized in the other areas. Based on the results, the hypothesis that the native range of the species is in Northeast Asia was supported, and the populations outside this range were concluded to be non-indigenous populations.

Brown algae are characterized by a remarkable diversity of life cycles, sexual systems, and reproductive modes, and these traits seem to be very labile across the whole group. This diversity makes them ideal models to test existing theories on the evolution of alternation between generations, and to examine correlations between life cycle and reproductive life history traits. In this study, we investigate the dynamics of trait evolution for four life-history traits: life cycle, sexual system, level of gamete dimorphism and gamete parthenogenetic capacity. We assign states to up to 70 species in a multi-gene phylogeny of brown algae, and use maximum likelihood and Bayesian analyses of correlated evolution, taking phylogeny into account, to test for correlations between life history traits and sexual systems, and to investigate the sequence of trait acquisition. Our analyses are consistent with the prediction that diploid growth may evolve because it allows the complementation of deleterious mutations, and that haploid sex determination is ancestral in relation to diploid sex determination. However, the idea that increased zygotic and diploid growth is associated with increased sexual dimorphism is not supported by our analysis. Finally, it appears that in the brown algae isogamous species evolved from anisogamous ancestors.

Although nutrient enrichment of estuarine and coastal waters is considered a key factor for the development of green tides, the extent, distribution, and species composition of blooms vary among systems of similar nutrient loading, which compromises our ability to predict these events based on information about nutrient status alone. Additional factors may play a role in the control and development of macroalgal blooms. The identification of relevant scales of variation is a necessary prerequisite before explanatory models can be proposed and tested. In this study spatial and temporal patterns of biomass distribution were assessed for two Ulva morphologies in two Irish estuaries heavily affected by green tides (wet biomass >1 kg m−2 during the peak bloom). Moreover, using genetic markers, the species composition of these green tides was assessed. Results revealed that these blooms were multi-specific, with Ulva prolifera, U. compressa and U.rigida the most frequent species. The species U. prolifera and U. compressa usually showed a tubular morphology, while U. rigida was mainly laminar. A seasonal succession common to both estuaries was also identified, with the bloom dominated by tubular species during spring and early summer, and co-dominated by tubular and laminar morphologies during late summer and autumn. Moreover, tubular and laminar morphologies exhibited different distribution patterns, with tubular morphologies varying at bigger spatial scales and higher biomass than the laminar. As tubular and laminar morphologies exhibited different distribution patterns, varying tubular morphologies along bigger spatial scales with higher biomass levels than the laminar. Considering that tubular morphologies were usually anchored to the sediment, while laminar Ulva were usually observed free-floating, these differences could explain a differential influence by water motion. An important annual and decadal variability in biomass levels of Ulva was observed, in the case of the Tolka estuary a noticeable increase over the last two decades. These findings should be considered for the development of management and monitoring strategies since the different habitat of laminar and tubular morphologies (anchored vs. free-floating) may play an important role in the balance of nutrients and biomass in the estuary, or determine the response to pollutant exposure. Furthermore, the presence of different species with different ecological requirements could favour the duration and extension of the bloom though temporal and spatial successions.

Through the current trend for bioprospecting, marine organisms - particularly algae - are becoming increasingly known for their osteogenic potential. Such organisms may provide novel treatment options for osteoporosis and other musculoskeletal conditions, helping to address their large healthcare burden and the limitations of current therapies. In this study, extracts from two red algae – Plocamium lyngbyanum and Ceramium secundatum – were tested in vitro and in vivo for their osteogenic potential. In vitro, the growth of human bone marrow stromal cells (hBMSCs) was significantly greater in the presence of the extracts, particularly with P. lyngbyanum treatment. Osteogenic differentiation was promoted more by C. secundatum (70 µg/ml), though P. lyngbyanum had greater in vitro mineralisation potential. Both species caused a marked and dose-dependent increase in the opercular bone area of zebrafish larvae. Our findings therefore indicate the presence of bioactive components in P. lyngbyanum and C. secundatum extracts, which can promote both in vitro and in vivo osteogenic activity.

Species of Prasiolales (Trebouxiophyceae, Chlorophyta) are among the most common terrestrial and freshwater algae in polar regions. Comprehensive molecular studies of this group are available for Antarctica, but not yet for Arctic regions. We examined the diversity of the Prasiolales in the Svalbard Archipelago combining morphological observations of field-collected material, culture studies, molecular data (plastid rbcL and tufA sequences) and literature records. We confirmed the widespread occurrence of Prasiola crispa and P. fluviatilis, species recorded from Spitsbergen since the 19th century. Molecular phylogenetic analyses led to the discovery of two new genera of Prasiolales. Prasionema payeri is morphologically identical to filamentous stages of P. crispa, but represents an early-diverging lineage in the order. Prasionella wendyae is a colonial alga reproducing by aplanospores; its phylogenetic position is among the basal lineages of the order, but it could not be reliably reconstructed du...

DNA sequences from type material in the nongeniculate coralline genus Lithophyllum were used to unambiguously link some European species names to field-collected specimens, thus providing a great advance over morpho-anatomical identifi-cation. In particular, sequence comparisons of rbcL, COI and psbA genes from field-collected specimens allowed the following conclusion: the generitype species, L. incrustans, occurs mostly as subtidal rhodoliths and crusts on both Atlantic and Mediterranean coasts, and not as the common, NE Atlantic, epilithic, intertidal crust reported in the literature. The heterotypic type material of L. hibernicum was narrowed to one rhodolith belonging in Lithophyllum. As well as occurring as a subtidal rhodolith, L. hibernicum is a common, epilithic and epizoic crust in the intertidal zone from Ireland south to Mediterranean France. A set of four features distinguished L. incrustans from L. hibernicum, including epithallial cell diameter, pore canal shape of sporangial conceptacles and sporangium height and diameter. An rbcL sequence of the lectotype of Lithophyllum bathyporum, which was recently proposed to accommodate Atlantic intertidal collections of L. incrustans, corresponded to a distinct taxon hitherto known only from Brittany as the subtidal, bisporangial, lectotype, but also occurs intertidally in Atlantic Spain. Specimens from Ireland and France morpho-anatomically identified as L. fasciculatum and a specimen from Cornwall likewise identified as L. duckerae were resolved as L. incrustans and L. hibernicum, respectively.

Rhodoliths are free-living calcifying red algae that form extensive beds in shallow marine benthic environments (

For the Mediterranean Sea, and indeed most of the world's oceans, the biodiversity and biogeography of eukaryotic pathogens infecting marine macroalgae remains poorly known, yet their ecological impact is probably significant. Based on 2 sampling campaigns on the Greek island of Lesvos in 2009 and 1 in northern Greece in 2012, this study provides first records of 3 intracellular eukaryotic pathogens infecting filamentous brown algae at these locations: Eury - chas ma dicksonii, Anisolpidium sphacellarum, and A. ectocarpii. Field and microscopic observa- tions of the 3 pathogens are complemented by the first E. dicksonii large subunit ribosomal RNA (LSU rRNA) gene sequence analyses of isolates from Lesvos and other parts of the world. The lat- ter highlights the monophyly of E. dicksonii worldwide and confirms the basal position of this pathogen within the oomycete lineage (Peronosporomycotina). The results of this study strongly support the notion that the geographic distribution of the relatively few eukaryotic seaweed pathogens is probably much larger than previously thought and that many of the world's marine bioregions remain seriously undersampled and understudied in this respect.

International audience

International audience

Enrichment of nutrients and metals in seawater associated with anthropogenic activities can threaten aquatic ecosystems. Consequently, nutrient and metal concentrations are parameters used to define water quality. The European Union's Water Framework Directive (WFD) goes further than a contaminant-based approach and utilises indices to assess the Ecological Status (ES) of transitional water bodies (e.g. estuaries and lagoons). One assessment is based upon the abundance of opportunistic Ulva species, as an indication of eutrophication. The objective of this study was to characterise Ireland's Ulva blooms through the use of WFD assessment, metal concentrations and taxonomic identity. Furthermore, the study assessed whether the ecological assessment is related to the metal composition in the Ulva. WFD algal bloom assessment revealed that the largest surveyed blooms had an estimated biomass of 2164 metric tonnes (w/w). DNA sequences identified biomass from all locations as Ulva rigida, with the exception of New Quay, which was Ulva rotundata. Some blooms contained significant amounts of As, Cu, Cr, Pb and Sn. The results showed that all metal concentrations had a negative relationship (except Se) with the Ecological Quality Ratio (EQR). However, only in the case of Mn were these differences significant (p = 0.038). Overall, the metal composition and concentrations found in Ulva were site dependent, and not clearly related to the ES. Nevertheless, sites with a moderate or poor ES had a higher variability in the metals levels than in estuaries with a high ES.

Genetic affiliation, nuclear DNA content, and gamete functioning were examined in small salt marsh Fucus from three localities in western Ireland. Individuals with small and dioecious receptacles were found at all localities, but production of germlings was only evident from those at Locality 1. Here, the Fucus vegetation formed a morphological cline from F. vesiculosus with bladders in the mid intertidal to small Fucus individuals lacking bladders in the salt marsh of the upper intertidal. Measurements of nuclear DNA content ranged from 1 1.8 pg at this locality, with the F. vesiculosus individuals in the lower range. At the two other localities, the small salt marsh Fucus formed distinct morphological entities. Microsatellite analyses revealed that the small salt marsh Fucus individuals from Locality 2 were derived mainly from F. vesiculosus, whereas those from Locality 3 were hybrids between F. vesiculosus and F. spiralis with greatest affiliation to F. spiralis. While the small salt marsh Fucus forms from Locality 2 had high nuclear DNA content (ca. 4 pg) and were probably octoploids, the small salt marsh ucus from Locality 3 formed two groups: one with high (3.9 4.6 pg) and one with low (1.5 1.9 pg) nuclear DNA content. Nuclear DNA content measured in individuals from Locality 3 varied between 1.1 2.8 pg in F. vesiculosus and 2 3.5 pg in F. spiralis and showed a more or less stepwise increase in both species, consistent with polyploidy. We hypothesize that the small salt marsh Fucus forms originate from genome size changes in the parental taxa. The final version of this research has been published in European Journal of Phycology. © 2017 Taylor & Francis

Heesch S., Sutherland J.E. and Nelson W.A. 2012. Marine Prasiolales (Trebouxiophyceae, Chlorophyta) from New Zealand and the Balleny Islands, with descriptions of Prasiola novaezelandiae sp. nov. and Rosenvingiella australis sp. nov. Phycologia 51: 217–227. DOI: 2216/10-95.1 Molecular systematic studies using rbcL sequences of marine populations of Prasiolales in the New Zealand archipelago (29 to 54°S) and the Balleny Islands (66°15′ to 67°10′S) confirm the presence of at least six species in this region. Four species of Prasiola are distinguished by the sequence analyses. Three populations from the main islands of New Zealand belong to a new species, described here as Prasiola novaezelandiae sp. nov. One species belongs to the Prasiola stipitata complex; another species from Antipodes Island, referred to here as Prasiola ‘borealis’, is related to specimens from British Columbia and Alaska in the North Pacific. The fourth species, Prasiola crispa, previously recorded from mainland New Zealand, w...

The genetic diversity of the green algal genus Ulva sensu lato in the New Zealand region was surveyed, examining rbcL sequences of 581 samples from a wide geographical range. Twenty-four genetically distinct taxa were discovered in New Zealand waters, belonging to three genera–Ulva (19 species), Umbraulva (four species) and Gemina (one species). Of the 19 species of Ulva reported here, 13 could be identified to the species level based on morphological and genetic data. The remaining six species cannot currently be assigned to known species groups due to a lack of close homology with sequences in GenBank. These species may include undescribed endemic taxa, recognised taxa for which rbcL sequences are not yet available, or may represent cryptogenic species. The genus Umbraulva is recorded for the first time for the New Zealand region and for the Southern Hemisphere. Of the four species distinguished, one is considered to be introduced to the region and the other three are undescribed indigenous taxa. Subant...

The phylogenetic affinities of the brown alga Herpodiscus durvillaeae, an obligate parasite of Durvillaea antarctica (Fucales, Phaeophyceae) endemic to New Zealand, were analysed using combined partial nuclear encoded ribosomal DNA (26S) and plastid encoded RuBisCO (rbcL) gene sequences. Results from phylogenetic analyses place this species within the order Sphacelariales. Molecular data were supported by two morphological features characteristic for the Sphacelariales sensu stricto: the presence of apical cells and the transitory blackening of the cell wall with sodium hypochlorite solution (‘Eau de Javel’). However, the strongly heteromorphic life history distinguishes H. durvillaeae from all other members of the Sphacelariales of which the life cycle is known. This variability in life history provides a new systematic character for the order and should be taken into account in any comprehensive systematic revision of the Sphacelariales.

Carbon physiology of a genetically identified Ulva rigida was investigated under different CO2(aq) and light levels. The study was designed to answer whether (1) light or exogenous inorganic carbon (Ci) pool is driving growth; and (2) elevated CO2(aq) concentration under ocean acidification (OA) will downregulate CAext-mediated [Formula: see text] dehydration and alter the stable carbon isotope (δ (13)C) signatures toward more CO2 use to support higher growth rate. At pHT 9.0 where CO2(aq) is1 μmol L(-1), inhibition of the known [Formula: see text] use mechanisms, that is, direct [Formula: see text] uptake through the AE port and CAext-mediated [Formula: see text] dehydration decreased net photosynthesis (NPS) by only 56-83%, leaving the carbon uptake mechanism for the remaining 17-44% of the NPS unaccounted. An in silico search for carbon-concentrating mechanism elements in expressed sequence tag libraries of Ulva found putative light-dependent [Formula: see text] transporters to which the remaining NPS can be attributed. The shift in δ (13)C signatures from -22‰ toward -10‰ under saturating light but not under elevated CO2(aq) suggest preference and substantial [Formula: see text] use to support photosynthesis and growth. U. rigida is Ci saturated, and growth was primarily controlled by light. Therefore, increased levels of CO2(aq) predicted for the future will not, in isolation, stimulate Ulva blooms.

The roles of Biological Resource Centres (BRCs), such as the Culture Collection of Algae and Protozoa (CCAP), have extended beyond their traditional maintenance and provision of curated microorganisms to the user community. A major driver for change has been the exponential increase in metagenomics and environmental sequencing data over the last few years. This has underlined a critical requirement for molecular information on reference biological materials, which would allow better taxonomic interpretation, greater biological understanding and additional exploitation of these data. This is especially relevant for the relatively poorly studied protists (algal/autotrophic as well as heterotrophic) and prokaryotic cyanobacteria, which despite their huge biodiversity, reflected in the genomic data that has been generated, are under-represented in BRCs worldwide. Here we describe the functionalities of the Culture Collection of Algae and Protozoa (CCAP) KnowledgeBase (http://www.ccap.ac.uk), developed as a one-stop shop for quality-controlled biological material, hyperlinked to manually curated molecular, bibliographic and taxonomic information. This has been built around the CCAP live collection, which constitutes one of the most genotypically diverse collections in the world with representatives of all the major eukaryotic lineages and the cyanobacteria.

The algae are an extremely diverse group of organisms from several different perspectives; including their phylogeny, their basic biology and biochemistry, the range of complexity they exhibit and their adaptation to a large number of different habitats. As a result, algal research touches on a broad spectrum of questions ranging from the importance of algae as key species in marine ecosystems to algae as a source of novel biomolecules and bioprocesses. Two key developments have accelerated research in this field over the past few years. The first is the application of high-throughput sequencing approaches both to whole genome sequencing and to metagenomic exploration of marine environments. The second is the emergence of model organisms in several of the less well studied algal lineages. These model organisms are important because they permit efficient application of genomic approaches to these groups. This chapter will describe how genomic research is providing new insights into many aspects of algal biology and will attempt to outline where this research is likely to lead in the future.

Brown algae (Phaeophyceae) are complex photosynthetic organisms with a very different evolutionary history to green plants, to which they are only distantly related. These seaweeds are the dominant species in rocky coastal ecosystems and they exhibit many interesting adaptations to these, often harsh, environments. Brown algae are also one of only a small number of eukaryotic lineages that have evolved complex multicellularity (Fig. 1). We report the 214 million base pair (Mbp) genome sequence of the filamentous seaweed Ectocarpus siliculosus (Dillwyn) Lyngbye, a model organism for brown algae, closely related to the kelps (Fig. 1). Genome features such as the presence of an extended set of light-harvesting and pigment biosynthesis genes and new metabolic processes such as halide metabolism help explain the ability of this organism to cope with the highly variable tidal environment. The evolution of multicellularity in this lineage is correlated with the presence of a rich array of signal transduction genes. Of particular interest is the presence of a family of receptor kinases, as the independent evolution of related molecules has been linked with the emergence of multicellularity in both the animal and green plant lineages. The Ectocarpus genome sequence represents an important step towards developing this organism as a model species, providing the possibility to combine genomic and genetic approaches to explore these and other aspects of brown algal biology further. © 2010 Macmillan Publishers Limited. All rights reserved.

International audience; Ectocarpus siliculosus has been proposed as a genetic and genomic model for the brown algae and the 214 Mbp genome of this organism has been sequenced. The aim of this project was to obtain a chromosome-scale view of the genome by constructing a genetic map using microsatellite markers that were designed based on the sequence supercontigs. To map genetic markers, a segregating F 2 population was generated from a cross between the sequenced strain (Ec 32) and a compatible strain from northern Chile. Amplified fragment length polymorphism (AFLP) analysis indicated a significant degree of polymorphism (41%) between the genomes of these two parental strains. Of 1,152 microsatellite markers that were selected for analysis based on their location on long supercontigs, their potential as markers and their predicted ability to amplify a single genomic locus, 407 were found to be polymorphic. A genetic map was constructed using 406 markers, resulting in 34 linkage groups. The 406 markers anchor 325 of the longest supercontigs on to the map, representing 70.1% of the genome sequence. The Ectocarpus genetic map described here not only provides a large-scale assembly of the genome sequence, but also represents an important tool for future genetic analysis using this organism.