A small armed dinoflagellate bloomed in the aquaculture ponds off the coast of Liaodong Bay, Bohai Sea of China, resulting in heavy mortalities of the cultured prawns （Penaeusjaponicus） and larvae of Chinese mitten ...A small armed dinoflagellate bloomed in the aquaculture ponds off the coast of Liaodong Bay, Bohai Sea of China, resulting in heavy mortalities of the cultured prawns （Penaeusjaponicus） and larvae of Chinese mitten handed crabs （Eriocheir sinensis）. The bloom-forming species was successfully isolated, and cellular morphology of the specimen was consequently investigated through light, fluorescent and electron microscopy. The small （（14.4±1.6） μm in length） ellipsoid cells show typical Heterocapsa thecal plate arrangement （Po, cp, 5′, 3a, 7″, 6c, 5s, 5′″, 2″″）. The episome is evidently bigger than the hyposome. One to three spherical pyrenoids are located above or beside the large elongated nucleus. The body scale is characterized by a triangle basal plate with one central upright and nine peripheral spines. Above all, Heterocapsa bohaiensis could be distinguished from other Heterocapsa species by the combination of the cell size, morphology, cellular structure and body scale. Sequence analyses of both ITS and LSU regions reveal the significant genetic divergence between H. bohaiensis and other established species in this genus, further supporting novelty of this species. Noticeably, different sample treatment methods resulted in morphological variation of the apical pore complex （APC） of H. bohaiensis, which needs to be taken into account in future study.展开更多
Microalgae are photosynthetic microorganisms that function as primary producers in aquatic ecosystems. Some species of microalgae undergo rapid growth and cause harmful blooms in marine ecosystems. Heterocapsa triquet...Microalgae are photosynthetic microorganisms that function as primary producers in aquatic ecosystems. Some species of microalgae undergo rapid growth and cause harmful blooms in marine ecosystems. Heterocapsa triquetra is one of the most common bloom-forming species in estuarine and coastal waters worldwide. Although this species does not produce toxins, unlike some other Heterocapsa species, the high density of its blooms can cause significant ecological damage. We developed a H. triquetra species-specific nuclease protection assay sandwich hybridization（NPA-SH） probe that targets the large subunit of ribosomal RNA（LSU r RNA）. We tested probe specificity and sensitivity with five other dinoflagellates that also cause red tides. Our assay detected H.triquetra at a concentration of 1.5×10^4 cells/m L, more sensitive than required for a red-tide guidance warning by the Korea Ministry of Oceans and Fisheries in 2015（3.0×10^4 cells/m L）. We also used the NPA-SH assay to monitor H. triquetra in the Tongyeong region of the southern sea area of Korea during 2014. This method could detect H.triquetra cells within 3 h. Our assay is useful for monitoring H. triquetra under field conditions.展开更多
This paper investigates behaviors that a set of initial cell densities of Heterocapsa Circularisquama(HC)and Proroce nt rum Dentatum(PD)and a set of environmental factors disturbing the growth of HC and PD cells forme...This paper investigates behaviors that a set of initial cell densities of Heterocapsa Circularisquama(HC)and Proroce nt rum Dentatum(PD)and a set of environmental factors disturbing the growth of HC and PD cells formed in their growth process,which are actually fractal phenomena.First,the calculation of the fractal dimension of the set of initial cell densities of HC and PD is given in the paper.Second,by controlling the set of initial cell density,HC and PD cells grow according to a given growth target.The approximate or same behaviors of two different sets of initial cell densities of HC and PD are realized by introducing the coupling terms.Finally,the set of environmental factors distu rbing the growth of HC and PD cells is construe ted by introducing real parameters.Then the result that makes HC and PD cells growing according to a given growth target is reached by a proper mathematical transform to the real parameters.The approximate or same behaviors of the set of environmental factors disturbing the growth of HC and PD cells are realized by introducing the coupling terms.展开更多
Heterocapsa circularisquama RNA virus(HcRNAV) is the first single-stranded RNA virus to be characterized that infects dinoflagellates.The ability of HcRNAV coat protein(HcRNAV CP) to self-assemble into virus-like part...Heterocapsa circularisquama RNA virus(HcRNAV) is the first single-stranded RNA virus to be characterized that infects dinoflagellates.The ability of HcRNAV coat protein(HcRNAV CP) to self-assemble into virus-like particles(VLPs) in vitro suggested that heterologous expression was possible,and that the VLPs might be ideal nanocontainers for the targeted delivery of genes and chemicals.In this paper,we report the expression of a codon-optimized HcRNAV 109 CP gene in Pichia pastoris and the production of self-assembled HcRNAV VLPs using large-scale fermentation.The HcRNAV 109 CP gene was synthesized according to the codon preference of P.pastoris and cloned into a pPICZA vector.The recombinant plasmid pPICZA-CPsyns was transformed into P.pastoris by electroporation.The resulting yeast colonies were screened by PCR and analyzed for protein expression by SDS polyacrylamide gel electrophoresis.After large-scale fermentation,the yield of HcRNAV CPsyns reached approximately 2.5 g L 1 within 4 d.The HcRNAV VLPs were purified using PEG precipitation followed by cesium chloride density gradient ultracentrifugation,and were subsequently analyzed using UV spectrophotometry and transmission electron microscopy.Fluorescence dye-labeled myoglobin was loaded into the cages of the HcRNAV VLPs and the encapsulation was confirmed by fluorescence spectroscopy.The results point to the possible utilization in pharmacology or nanotechnology of HcRNAV VLPs produced by P.pastoris fermentation.展开更多
基金The NSFC-Shandong Joint Funded Project under contract No.U1406403the National Natural Science Foundation of China under contract Nos 41506191 and 41306171
文摘A small armed dinoflagellate bloomed in the aquaculture ponds off the coast of Liaodong Bay, Bohai Sea of China, resulting in heavy mortalities of the cultured prawns （Penaeusjaponicus） and larvae of Chinese mitten handed crabs （Eriocheir sinensis）. The bloom-forming species was successfully isolated, and cellular morphology of the specimen was consequently investigated through light, fluorescent and electron microscopy. The small （（14.4±1.6） μm in length） ellipsoid cells show typical Heterocapsa thecal plate arrangement （Po, cp, 5′, 3a, 7″, 6c, 5s, 5′″, 2″″）. The episome is evidently bigger than the hyposome. One to three spherical pyrenoids are located above or beside the large elongated nucleus. The body scale is characterized by a triangle basal plate with one central upright and nine peripheral spines. Above all, Heterocapsa bohaiensis could be distinguished from other Heterocapsa species by the combination of the cell size, morphology, cellular structure and body scale. Sequence analyses of both ITS and LSU regions reveal the significant genetic divergence between H. bohaiensis and other established species in this genus, further supporting novelty of this species. Noticeably, different sample treatment methods resulted in morphological variation of the apical pore complex （APC） of H. bohaiensis, which needs to be taken into account in future study.
基金The Public Welfare&Safety Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning under contract No.NRF-2013M3A2A1067529
文摘Microalgae are photosynthetic microorganisms that function as primary producers in aquatic ecosystems. Some species of microalgae undergo rapid growth and cause harmful blooms in marine ecosystems. Heterocapsa triquetra is one of the most common bloom-forming species in estuarine and coastal waters worldwide. Although this species does not produce toxins, unlike some other Heterocapsa species, the high density of its blooms can cause significant ecological damage. We developed a H. triquetra species-specific nuclease protection assay sandwich hybridization（NPA-SH） probe that targets the large subunit of ribosomal RNA（LSU r RNA）. We tested probe specificity and sensitivity with five other dinoflagellates that also cause red tides. Our assay detected H.triquetra at a concentration of 1.5×10^4 cells/m L, more sensitive than required for a red-tide guidance warning by the Korea Ministry of Oceans and Fisheries in 2015（3.0×10^4 cells/m L）. We also used the NPA-SH assay to monitor H. triquetra in the Tongyeong region of the southern sea area of Korea during 2014. This method could detect H.triquetra cells within 3 h. Our assay is useful for monitoring H. triquetra under field conditions.
基金the National Natural Science Foundation of China(Nos.U1806203 and 61533011).
文摘This paper investigates behaviors that a set of initial cell densities of Heterocapsa Circularisquama(HC)and Proroce nt rum Dentatum(PD)and a set of environmental factors disturbing the growth of HC and PD cells formed in their growth process,which are actually fractal phenomena.First,the calculation of the fractal dimension of the set of initial cell densities of HC and PD is given in the paper.Second,by controlling the set of initial cell density,HC and PD cells grow according to a given growth target.The approximate or same behaviors of two different sets of initial cell densities of HC and PD are realized by introducing the coupling terms.Finally,the set of environmental factors distu rbing the growth of HC and PD cells is construe ted by introducing real parameters.Then the result that makes HC and PD cells growing according to a given growth target is reached by a proper mathematical transform to the real parameters.The approximate or same behaviors of the set of environmental factors disturbing the growth of HC and PD cells are realized by introducing the coupling terms.
基金supported by the Pioneer Research Center Program through the National Research Program of Korea funded by the Ministry of Education,Science and Technology,Korea (Grant M1071118001-08M1118-00110)(2010)
文摘Heterocapsa circularisquama RNA virus(HcRNAV) is the first single-stranded RNA virus to be characterized that infects dinoflagellates.The ability of HcRNAV coat protein(HcRNAV CP) to self-assemble into virus-like particles(VLPs) in vitro suggested that heterologous expression was possible,and that the VLPs might be ideal nanocontainers for the targeted delivery of genes and chemicals.In this paper,we report the expression of a codon-optimized HcRNAV 109 CP gene in Pichia pastoris and the production of self-assembled HcRNAV VLPs using large-scale fermentation.The HcRNAV 109 CP gene was synthesized according to the codon preference of P.pastoris and cloned into a pPICZA vector.The recombinant plasmid pPICZA-CPsyns was transformed into P.pastoris by electroporation.The resulting yeast colonies were screened by PCR and analyzed for protein expression by SDS polyacrylamide gel electrophoresis.After large-scale fermentation,the yield of HcRNAV CPsyns reached approximately 2.5 g L 1 within 4 d.The HcRNAV VLPs were purified using PEG precipitation followed by cesium chloride density gradient ultracentrifugation,and were subsequently analyzed using UV spectrophotometry and transmission electron microscopy.Fluorescence dye-labeled myoglobin was loaded into the cages of the HcRNAV VLPs and the encapsulation was confirmed by fluorescence spectroscopy.The results point to the possible utilization in pharmacology or nanotechnology of HcRNAV VLPs produced by P.pastoris fermentation.
