title: Mapping the Distribution of Cysts from the Toxic Dinoflagellate Cochlodinium polykrikoides in Bloom-Prone Estuaries by a Novel Fluorescence In Situ Hybridization Assay.
abstract: Cochlodinium polykrikoides is a cosmopolitan dinoflagellate that is notorious for causing fish-killing harmful algal blooms (HABs) across North America and Asia. While recent laboratory and ecosystem studies have definitively demonstrated that Cochlodinium forms resting cysts that may play a key role in the dynamics of its HABs, uncertainties regarding cyst morphology and detection have prohibited even a rudimentary understanding of the distribution of C. polykrikoides cysts in coastal ecosystems. Here, we report on the development of a fluorescence in situ hybridization (FISH) assay using oligonucleotide probes specific for the large subunit (LSU) ribosomal DNA (rDNA) of C. polykrikoides. The LSU rDNA-targeted FISH assay was used with epifluorescence microscopy and was iteratively refined to maximize the fluorescent reaction with C. polykrikoides and minimize cross-reactivity. The final LSU rDNA-targeted FISH assay was found to quantitatively recover cysts made by North American isolates of C. polykrikoides but not cysts formed by other common cyst-forming dinoflagellates. The method was then applied to identify and map C. polykrikoides cysts across bloom-prone estuaries. Annual cyst and vegetative cell surveys revealed that elevated densities of C. polykrikoides cysts (>100 cm(-3)) during the spring of a given year were spatially consistent with regions of dense blooms the prior summer. The identity of cysts in sediments was confirmed via independent amplification of C. polykrikoides rDNA. This study mapped C. polykrikoides cysts in a natural marine setting and indicates that the excystment of cysts formed by this harmful alga may play a key role in the development of HABs of this species.
authors.affiliation: Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, New York, New York, USA.
authors.forename: Theresa K
authors.initials: TK
authors.lastname: Hattenrath-Lehmann
authors.affiliation: Ocean University of China, College of Environmental Science and Engineering, Qingdao, People's Republic of China.|Ocean University of China, Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhen
authors.affiliation: Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, New York, New York, USA.
authors.forename: Ryan B
authors.initials: RB
authors.lastname: Wallace
authors.affiliation: Chinese Academy of Science, Institute of Oceanology, Key Laboratory of Marine Ecology and Environmental Sciences, Qingdao, China yingzhong.tang@qdio.ac.cn christopher.gobler@stonybrook.edu.
authors.forename: Ying-Zhong
authors.initials: YZ
authors.lastname: Tang
authors.affiliation: Stony Brook University, School of Marine and Atmospheric Sciences, Southampton, New York, New York, USA yingzhong.tang@qdio.ac.cn christopher.gobler@stonybrook.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gobler
mesh_terms: D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004141:Dinoflagellida / Q000235:genetics / Q000302:isolation & purification*; D063366:Estuaries; D019015:Geologic Sediments / Q000469:parasitology*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008856:Microscopy, Fluorescence; D009656:North America; D015345:Oligonucleotide Probes / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012621:Seasons; D012680:Sensitivity and Specificity; D033761:Spores, Protozoan / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D015345:Oligonucleotide Probes; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S