Analysis of small microplastics in coastal surface water samples of the subtropical island of Okinawa, Japan.

Marine plastic debris is widely recognized as a global environmental issue. Small microplastic particles, with an upper size limit of 20 μm, have been identified as having the highest potential for causing damage to marine ecosystems. Having accurate methods for quantifying the abundance of such particles in a natural environment is essential for defining the extent of the problem they pose.

Response of Coral Reef Dinoflagellates to Nanoplastics under Experimental Conditions Suggests Downregulation of Cellular Metabolism.

Plastic products contribute heavily to anthropogenic pollution of the oceans. Small plastic particles in the microscale and nanoscale ranges have been found in all marine ecosystems, but little is known about their effects upon marine organisms. In this study, we examine changes in cell growth, aggregation, and gene expression of two symbiotic dinoflagellates of the family Symbiodiniaceae, (clade A3), and sp.

Dinoflagellate nucleus contains an extensive endomembrane network, the nuclear net.

Dinoflagellates are some of the most common eukaryotic cells in the ocean, but have very unusual nuclei. Many exhibit a form of closed mitosis (dinomitosis) wherein the nuclear envelope (NE) invaginates to form one or more trans-nuclear tunnels. Rather than contact spindles directly, the chromatids then bind to membrane-based kinetochores on the NE.

Microbial arms race: Ballistic "nematocysts" in dinoflagellates represent a new extreme in organelle complexity.

We examine the origin of harpoon-like secretory organelles (nematocysts) in dinoflagellate protists. These ballistic organelles have been hypothesized to be homologous to similarly complex structures in animals (cnidarians); but we show, using structural, functional, and phylogenomic data, that nematocysts evolved independently in both lineages. We also recorded the first high-resolution videos of nematocyst discharge in dinoflagellates.