What Was Old Is New Again: The Pennate Diatom (Gaillon) Simonsen in the Multi-Omic Age.

The marine pennate diatom has long been known for its characteristic blue pigment marennine, which is responsible for the greening of invertebrate gills, a natural phenomenon of great importance for the oyster industry. For two centuries, this taxon was considered unique; however, the recent description of a new blue species revealed unsuspected biodiversity. Marennine-like pigments are natural blue dyes that display various biological activities-e.

Mitochondrial and Plastid Genomes of the Monoraphid Diatom .

We provide for the first time the complete plastid and mitochondrial genomes of a monoraphid diatom: The mitogenome is 41,957 bp in size and displays two group II introns in the gene. The 187,029 bp plastid genome features the typical quadripartite architecture of diatom genomes. It contains a group II intron in the gene that overlaps the large single-copy and the inverted repeat region.

Extreme Enlargement of the Inverted Repeat Region in the Plastid Genomes of Diatoms from the Genus .

We sequenced the plastid genomes of three diatoms from the genus , including two strains formerly designated as . At 208,097 and 216,580 bp, the plastid genomes of the latter strains are the largest ever sequenced among diatoms and their increased size is explained by the massive expansion of the inverted repeat region. Important rearrangements of gene order were identified among the two populations of cf.

Multigene phylogenetic data place monoraphid diatoms Schizostauron and Astartiella along with other fistula-bearing genera in the Stauroneidaceae.

Presented here are new insights into the marine monoraphid diatom genera Schizostauron and Astartiella, based on molecular and morphological data, including descriptions of new species. Although no unambiguous morphological synapomorphies between the two genera are currently recognized, they are closely related by DNA sequence data. Heterovalvate frustules of Schizostauron are characterized by a bifid stauros on the raphe-bearing valve and intricate areolate occlusions on the sternum valve.

, A Novel Cosmopolitan Species of Blue Diatoms.

Specimens of a new species of blue diatoms from the genus Simonsen were discovered in geographically distant sampling sites, first in the Canary Archipelago, then North Carolina, Gulf of Naples, the Croatian South Adriatic Sea, and Turkish coast of the Eastern Mediterranean Sea. An exhaustive characterization of these specimens, using a combined morphological and genomic approach led to the conclusion that they belong to a single new to science cosmopolitan species, sp. nov.

Mitogenome sequence of a Black Sea isolate of the kinetoplastid .

We obtained the mitogenome sequence of a Black Sea isolate of the kinetoplastid . This sequence consists of two contigs totaling 24,925 bp and encodes ten protein-coding genes, one conserved ORF and one rRNA gene. Alignment of the Black Sea mitogenome with the limited sequence data currently available in public databases for another strain of revealed significant genetic divergence between the two isolates.

Marennine, promising blue pigments from a widespread Haslea diatom species complex.

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting.