Complete Genome Sequence of , filamentous colony-making Chroococcales with the analysis of FraC gene influencing filament integrity.

The complete genome of was sequenced. The genome size is 4.02 Mbp, including 3886286 bp circular chromosome and four circular plasmids (31516, 42453, 38085 and 24903 bp).

Reorganization of the ancestral sex-determining regions during the evolution of trioecy in Pleodorina starrii.

The coexistence of three sexual phenotypes (male, female and bisexual) in a single species, 'trioecy', is rarely found in diploid organisms such as flowering plants and invertebrates. However, trioecy in haploid organisms has only recently been reported in a green algal species, Pleodorina starrii. Here, we generated whole-genome data of the three sex phenotypes of P.

Characterization of a bloom-associated alphaproteobacterial lineage, 'Candidatus Phycosocius': insights into freshwater algal-bacterial interactions.

Marine bacterial lineages associated with algal blooms, such as the Roseobacter clade, have been well characterized in ecological and genomic contexts, yet such lineages have rarely been explored in freshwater blooms. This study performed phenotypic and genomic analyses of an alphaproteobacterial lineage 'Candidatus Phycosocius' (denoted the CaP clade), one of the few lineages ubiquitously associated with freshwater algal blooms, and described a novel species: 'Ca. Phycosocius spiralis.

Genomic analysis of an ultrasmall freshwater green alga, Medakamo hakoo.

Ultrasmall algae have attracted the attention of biologists investigating the basic mechanisms underlying living systems. Their potential as effective organisms for producing useful substances is also of interest in bioindustry. Although genomic information is indispensable for elucidating metabolism and promoting molecular breeding, many ultrasmall algae remain genetically uncharacterized.

Cryopreservation of two species of the multicellular volvocine green algal genus Astrephomene.

Background: Astrephomene is an interesting green algal genus that, together with Volvox, shows convergent evolution of spheroidal multicellular bodies with somatic cells of the colonial or multicellular volvocine lineage. A recent whole-genome analysis of A. gubernaculifera resolved the molecular-genetic basis of such convergent evolution, and two species of Astrephomene were described.

Rapid transcriptomic and physiological changes in the freshwater pennate diatom Mayamaea pseudoterrestris in response to copper exposure.

Diatoms function as major primary producers, accumulating large amounts of biomass in most aquatic environments. Given their rapid responses to changes in environmental conditions, diatoms are used for the biological monitoring of water quality and for performing ecotoxicological tests in aquatic ecosystems. However, the molecular basis for their toxicity to chemical compounds remains largely unknown.

Cryopreservation of vegetative cells and zygotes of the multicellular volvocine green alga Gonium pectorale.

Background: Colonial and multicellular volvocine green algae have been extensively studied recently in various fields of the biological sciences. However, only one species (Pandorina morum) has been cryopreserved in public culture collections.

Results: Here, we investigated conditions for cryopreservation of the multicellular volvocine alga Gonium pectorale using vegetative colonies or cells and zygotes.

What Happened before Losses of Photosynthesis in Cryptophyte Algae?

In many lineages of algae and land plants, photosynthesis was lost multiple times independently. Comparative analyses of photosynthetic and secondary nonphotosynthetic relatives have revealed the essential functions of plastids, beyond photosynthesis. However, evolutionary triggers and processes that drive the loss of photosynthesis remain unknown.

Genome sequencing of the NIES Cyanobacteria collection with a focus on the heterocyst-forming clade.

Cyanobacteria are a diverse group of Gram-negative prokaryotes that perform oxygenic photosynthesis. Cyanobacteria have been used for research on photosynthesis and have attracted attention as a platform for biomaterial/biofuel production. Cyanobacteria are also present in almost all habitats on Earth and have extensive impacts on global ecosystems.

Identification of a dual orange/far-red and blue light photoreceptor from an oceanic green picoplankton.

Photoreceptors are conserved in green algae to land plants and regulate various developmental stages. In the ocean, blue light penetrates deeper than red light, and blue-light sensing is key to adapting to marine environments. Here, a search for blue-light photoreceptors in the marine metagenome uncover a chimeric gene composed of a phytochrome and a cryptochrome (Dualchrome1, DUC1) in a prasinophyte, Pycnococcus provasolii.

Development of a time-series shotgun metagenomics database for monitoring microbial communities at the Pacific coast of Japan.

Although numerous metagenome, amplicon sequencing-based studies have been conducted to date to characterize marine microbial communities, relatively few have employed full metagenome shotgun sequencing to obtain a broader picture of the functional features of these marine microbial communities. Moreover, most of these studies only performed sporadic sampling, which is insufficient to understand an ecosystem comprehensively. In this study, we regularly conducted seawater sampling along the northeastern Pacific coast of Japan between March 2012 and May 2016.

The Rubisco small subunits in the green algal genus Chloromonas provide insights into evolutionary loss of the eukaryotic carbon-concentrating organelle, the pyrenoid.

Background: Pyrenoids are protein microcompartments composed mainly of Rubisco that are localized in the chloroplasts of many photosynthetic organisms. Pyrenoids contribute to the CO-concentrating mechanism. This organelle has been lost many times during algal/plant evolution, including with the origin of land plants.

Comparative genome analysis of test algal strain NIVA-CHL1 (Raphidocelis subcapitata) maintained in microalgal culture collections worldwide.

Raphidocelis subcapitata is one of the most frequently used species for algal growth inhibition tests. Accordingly, many microalgal culture collections worldwide maintain R. subcapitata for distribution to users.

Draft Genome Sequences of Four Microcystis aeruginosa Strains (NIES-3787, NIES-3804, NIES-3806, and NIES-3807) Isolated from Lake Kasumigaura, Japan.

is a bloom-forming cyanobacterium found in freshwater environments. The draft genomes of the strains NIES-3787, NIES-3804, NIES-3806, and NIES-3807, which were isolated from Lake Kasumigaura, Japan, were sequenced. The genome sizes of NIES-3787, NIES-3804, NIES-3806, and NIES-3807 were 4,524,637, 4,522,701, 4,370,004, and 4,378,226 bp, respectively.

Genomic Characteristics of the Toxic Bloom-Forming Cyanobacterium NIES-102.

, a bloom-forming cyanobacterium distributed mainly in freshwater environments, can be divided into at least 12 groups (A-K and X) based on multi-locus phylogenetic analyses. In this study, we characterized the genome of microcystin-producing NIES-102, assigned to group A, isolated from Lake Kasumigaura, Japan. The complete genome sequence of NIES-102 comprised a 5.

Draft Genome Sequences of Three Filamentous Cyanobacterial Strains, Dolichospermum planctonicum NIES-80, Planktothrix agardhii NIES-905, and Sphaerospermopsis reniformis NIES-1949.

Three freshwater planktonic filamentous cyanobacterial strains, NIES-80, NIES-905, and NIES-1949, were sequenced. The genome sizes of NIES-80, NIES-905, and NIES-1949 were 4,571,002 bp, 5,512,454 bp, and 6,025,023 bp, and the number of protein-coding genes in each genome was 4,009, 4,925, and 5,408, respectively.

Depth-dependent transcriptomic response of diatoms during spring bloom in the western subarctic Pacific Ocean.

Diatoms play important roles in primary production and carbon transportation in various environments. Large-scale diatom bloom occurs worldwide; however, metabolic responses of diatoms to environmental conditions have been little studied. Here, we targeted the Oyashio region of the western subarctic Pacific where diatoms bloom every spring and investigated metabolic response of major diatoms to bloom formation by comparing metatranscriptomes between two depths corresponding to different bloom phases.

The Draft Genome of a Hydrogen-producing Cyanobacterium, NIES-46.

is an economically important cyanobacterium that contains many useful products, including proteins, vitamins, lipids, and pigments, and it is distributed in several alkaline soda lakes. NIES-46 produces large amounts of hydrogen. In this study, we sequenced the NIES-46 draft genome and performed comparative analyses among species to elucidate the genomic background of this strain.

First Report of Strains Producing MC-FR and -WR Toxins in Japan.

Microcystins (MCs) are a group of cyclic heptapeptide hepatotoxins produced by and several other genera of cyanobacteria. Many structural variants have been characterized using various methods such as liquid chromatography-mass spectrometry (LC-MS) analysis, enzyme-linked immunosorbent assay (ELISA) and protein phosphatase 2A (PP2A) inhibition assay. The representative MC, MC-LR, and related cyanobacterial toxins strongly inhibit PP2A activity and can therefore be assayed by measuring the extent of PP2A inhibition.

A novel salt-tolerant genotype illuminates the sucrose gene evolution in freshwater bloom-forming cyanobacterium Microcystis aeruginosa.

Microcystis aeruginosa is a water bloom-forming cyanobacterium found in fresh and brackish water ecosystems worldwide. Previously, we showed that several instances of M. aeruginosa bloom in brackish water can be explained by the proliferation of salt-tolerant M.

Draft Genome Sequence of Microcystis aeruginosa NIES-4285, Isolated from Brackish Water (Lake Abashiri, Japan).

Microcystis aeruginosa is a bloom-forming cyanobacterium found in fresh and brackish waters worldwide. We sequenced the whole genome of M. aeruginosa NIES-4285, isolated from Lake Abashiri, Japan.