Category: Dinoflagellate genomics

Despite theoretical expectations, marine microeukaryote population are often highly structured and the mechanisms behind such patterns remain to be elucidated. These organisms display huge census population sizes, yet genotyping usually requires clonal strains originating from single cells, hindering proper population sampling. Estimating allelic frequency directly from population wide samples, without any isolation step, offers an interesting alternative. Here we validate the use of…

Dinoflagellate inhabitants of the reef-building corals exchange nutrients and signals with host cells, which often benefit the growth of both partners. Phytohormones serve as central hubs for signal integration between symbiotic microbes and their hosts, allowing appropriate modulation of plant growth and defense in response to various stresses. However, the presence and function of phytohormones in photosynthetic dinoflagellates and their function in the holobionts remain elusive. We…

The metabolic capabilities of animals have been derived from well-studied model organisms and are generally considered to be well understood. In animals, cysteine is an important amino acid thought to be exclusively synthesized through the transsulfuration pathway. Corals of the genus Acropora have lost cystathionine β-synthase, a key enzyme of the transsulfuration pathway, and it was proposed that Acropora relies on the symbiosis with dinoflagellates of the family Symbiodiniaceae for the…

Dinoflagellates play important roles in ecosystems as primary producers and consumers making natural products that can benefit or harm environmental and human health but are also potential therapeutics with unique chemistries. Annotations of dinoflagellate genes have been hampered by large genomes with many gene copies that reduce the reliability of transcriptomics, quantitative PCR, and targeted knockouts. This study aimed to functionally characterize dinoflagellate proteins by testing their…

Mitochondrial genomes of apicomplexans, dinoflagellates and chrompodellids that collectively make up the Myzozoa, encode only three proteins (COB, COX1, COX3), contain fragmented rRNAs, and display extensive recombination, RNA trans-splicing, and RNA-editing. The early-diverging Perkinsozoa is the final major myzozoan lineage whose mitochondrial genomes remained poorly characterized. Previous reports of Perkinsus genes indicated independent acquisition of non-canonical features, namely the…

The sunburst anemone Anthopleura sola is an abundant species inhabiting the intertidal zone of coastal California. Historically, this species has extended from Baja California, Mexico to as far north as Monterey Bay, CA. However, recently the geographic range of this species has expanded to Bodega Bay, CA, possibly as far north as Salt Point, CA. This species also forms symbiotic partnerships with the dinoflagellate Breviolum muscatinei, a member of the family Symbiodiniaceae. These partnerships…

The dinoflagellate family Suessiaceae comprises cosmopolitan species distributed across polar and tropical waters in both marine and freshwater ecosystems, encompassing free-living forms, symbionts, and parasites. Recently, species diversity within the family has rapidly expanded, now including a few species reported to cause red tides. Despite their ecological and evolutionary importance, classifying them within Suessiaceae is difficult due to the limitations of the existing molecular…

Stony corals often harbor intracellular photosynthetic dinoflagellate algae that receive dissolved inorganic nutrients. However, Dendrophyllia cribrosa is a non-symbiotic stony coral distributed in the western Pacific. We assembled a chromosome-level D. cribrosa genome using PacBio and Hi-C technologies. The final assembly was 625 Mb, distributed on 14 chromosomes, and contained 30,493 protein-coding genes. BUSCO analysis revealed a 96.8% of the metazoan genome. Comparative phylogenetic analysis…

Dinoflagellates of the family Symbiodiniaceae are crucial photosymbionts in corals and other marine organisms. Of these, Cladocopium goreaui is one of the most dominant symbiont species in the Indo-Pacific. Here, we present an improved genome assembly of C. goreaui combining new long-read sequence data with previously generated short-read data. Incorporating new full-length transcripts to guide gene prediction, the C. goreaui genome (1.2 Gb) exhibits a high extent of completeness (82.4% based on…

Since > 91% of dinoflagellates are proven auxotrophs of vitamin B(12) and the cobalamin synthetase W (CobW) is a key gene involved in vitamin B(12) synthesis pathway, a number of CobW domain-containing (CBWD) genes in dinoflagellates (DinoCBWDs) were surprisedly found from our transcriptomic and meta-transcriptomic studies. A total of 88 DinoCBWD genes were identified from the genomes and transcriptomes of four dinoflagellates, with five being cloned for full-lengths and characterized using the…