Gymnodinium catenatum is a dinoflagellate known to cause paralytic shellfish poisoning (PSP), commonly associated with human muscular paralysis, neurological symptoms, and, in extreme cases, death. In the present work, we developed a real-time PCR-based assay for the rapid detection of the toxic microalgal species, G. catenatum, in environmental bivalve mollusc samples as well as seawater samples. G. catenatum-specific primers and probe were designed on the ITS1-5.8S-ITS2 rDNA region. Hydrolysis…
Category: Dinoflagellate genomics
Apr 21
An overview of transcription in dinoflagellates
Dinoflagellates are a vital diverse family of unicellular algae widespread in various aquatic environments. Typically large genomes and permanently condensed chromosomes without histones make these organisms unique among eukaryotes in terms of chromatin structure and gene expression. Genomic and transcriptomic sequencing projects have provided new insight into the genetic foundation of dinoflagellate behaviors. Genes in tandem arrays, trans-splicing of mRNAs and lower levels of transcriptional…
Apr 14
Population genomics for symbiotic anthozoans: can reduced representation approaches be used for taxa without reference genomes?
Population genetic studies of symbiotic anthozoans have been historically challenging because their endosymbioses with dinoflagellates have impeded marker development. Genomic approaches like reduced representation sequencing alleviate marker development issues but produce anonymous loci, and without a reference genome, it is unknown which organism is contributing to the observed patterns. Alternative methods such as bait-capture sequencing targeting Ultra-Conserved Elements are now possible but…
Apr 13
Bioinformatic prediction of putative metallothioneins in non-ciliate protists
Intracellular ligands that bind heavy metals (HMs) and thereby minimize their detrimental effects to cellular metabolism are attracting great interest for a number of applications including bioremediation and development of HM-biosensors. Metallothioneins (MTs) are short, cysteine-rich, genetically encoded proteins involved in intracellular metal-binding and play a key role in detoxification of HMs. We searched approximately 700 genomes and transcriptomes of non-ciliate protists for novel…
Mar 07
Fatal affairs – conjugational transfer of a dinoflagellate-killing plasmid between marine Rhodobacterales
The roseobacter group of marine bacteria is characterized by a mosaic distribution of ecologically important phenotypes. These are often encoded on mobile extrachromosomal replicons. So far, conjugation had only been experimentally proven between the two model organisms Phaeobacter inhibens and Dinoroseobacter shibae. Here, we show that two large natural RepABC-type plasmids from D. shibae can be transferred into representatives of all known major Rhodobacterales lineages. Complete genome…
Mar 01
Genome-powered classification of microbial eukaryotes: focus on coral algal symbionts
Modern microbial taxonomy generally relies on the use of single marker genes or sets of concatenated genes to generate a framework for the delineation and classification of organisms at different taxonomic levels. However, given that DNA is the ‘blueprint of life’, and hence the ultimate arbiter of taxonomy, classification systems should attempt to use as much of the blueprint as possible to capture a comprehensive phylogenetic signal. Recent analysis of whole-genome sequences from coral reef…
Feb 24
Dataset of genome sequence, de novo assembly, and functional annotation of Ruegeria sp. (PBVC088), a marine bacterium associated with the toxin-producing harmful dinoflagellate, Pyrodinium bahamense var. compressum
The dataset comprises a whole-genome sequence of Ruegeria sp. PBVC088, a symbiotic (Gram-negative) bacterium associated with Pyrodinium bahamense var. compressum, which has been associated with harmful algal blooms in the coastal waters of west Sabah, Malaysia. Harmful algal blooms contribute to economic losses for the aquaculture industry, as well as human illnesses and fatalities due to paralytic shellfish poisoning. Bacteria-algae dynamics have posited that the interaction is potentially…
Feb 24
The Caspase Homologues in Scallop Chlamys farreri and Their Expression Responses to Toxic Dinoflagellates Exposure
The cysteine aspartic acid-specific protease (caspase) family is distributed across vertebrates and invertebrates, and its members are involved in apoptosis and response to cellular stress. The Zhikong scallop (Chlamys farreri) is a bivalve mollusc that is well adapted to complex marine environments, yet the diversity of caspase homologues and their expression patterns in the Zhikong scallop remain largely unknown. Here, we identified 30 caspase homologues in the genome of the Zhikong scallop…
Feb 19
Gymnodinialimonas ceratoperidinii gen. nov., sp. nov., isolated from rare marine dinoflagellate Ceratoperidinium margalefii
A bacterial strain, designated J12C1-MA-4^(T), was isolated from liquid culture of the dinoflagellate Ceratoperidinium margalefii. The bacterium was Gram-negative, aerobic, and rod-shaped. Oxidase and catalase were positive. Optimal growth was observed at 30 °C, pH 7.0, in the presence of 1% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene and a 92 core gene set suggested that the strain J12C1-MA-4^(T) belongs to the family Rhodobacteraceae in the class Alphaproteobacteria and represents…
Feb 04
Alexandriicola marinus gen. nov., sp. nov., a new member of the family Rhodobacteraceae isolated from marine phycosphere
Two yellow-pigmented bacterial strains, LZ-14 ^(T) and ABI-LZ29, were isolated from the cultivable phycosphere microbiota of the highly toxic marine dinoflagellate Alexandrium catenella LZT09 and demonstrated obvious microalgae growth-promoting potentials toward the algal host. To elucidate the taxonomic status of the two bioactive bacterial strains, they were subjected to a polyphasic taxonomic characterization. Both strains were found to be Gram-negative, aerobic, rod-shaped and motile; to…