Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae)

doi:10.1016/j.hal.2024.102658

	Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae)
	Li, Ruoxi 1,4; Deng, Yunyan 1,2,3; Shang, Lixia 1,2,3; Liu, Yuyang 1; Tao, Zhe 1,4; Chai, Zhaoyang 1,3; Tang, Ying Zhong 1,2,3
	2024-08-01
发表期刊	HARMFUL ALGAE
ISSN	1568-9883
卷号	137 页码:16
通讯作者	Chai, Zhaoyang(zhaoyangchai@qdio.ac.cn) ; Tang, Ying Zhong(yingzhong.tang@qdio.ac.cn)
摘要	Coral reef ecosystems are the most productive and biodiverse marine ecosystems, with their productivity levels highly dependent on the symbiotic dinoflagellates belonging to the family Symbiodiniaceae. As a unique life history strategy, resting cyst production is of great significance in the ecology of many dinoflagellate species, those HABs-causing species in particular, however, there has been no confirmative evidence for the resting cyst production in any species of the family Symbiodiniaceae. Based on morphological and life history observations of cultures in the laboratory and morpho-molecular detections of cysts from the marine sediments via fluorescence in situ hybridization (FISH), cyst photography, and subsequent singe -cyst PCR sequencing, here we provide evidences for the asexual production of resting cysts by Effrenium voratum , the free-living, red tide -forming, and the type species of the genus Effrenium in Symbiodiniaceae. The evidences from the marine sediments were obtained through a sequential detections: Firstly, E. voratum amplicon sequence variants (ASVs) were detected in the cyst assemblages that were concentrated with the sodium polytungstate (SPT) method from the sediments collected from different regions of China Seas by high -throughput next generation sequencing (NGS); Secondly, the presence of E. voratum in the sediments was detected by PCR using the species -specific primers for the DNA directly extracted from sediment; Thirdly, E. voratum cysts were confirmed by a combined approach of FISH using the species -specific probes, light microscopic (LM) photography of the FISH -positive cysts, and a subsequent single -cyst PCR sequencing for the FISH -positive and photographed cysts. The evidences from the laboratory -reared clonal cultures of E. voratum include that: 1) numerous cysts formed in the two clonal cultures and exhibited a spherical shape, a smooth surface, absence of ornaments, and a large red accumulation body; 2) cysts could maintain morphologically intact for a storage of two weeks to six months at 4 degrees C in darkness and of which 76 -92 % successfully germinated through an internal development processes within a time period of 3 -21 days after being transferred back to the normal culturing conditions; 3) two or four germlings were released from each cyst through the cryptopylic archeopyle in all cysts with continuous observations of germination processes; and 4) while neither sexual mating of gametes nor planozygote (cells with two longitudinal flagella) were observed, the haploidy of cysts was proven with flow cytometric measurements and direct LM measurements of fluorescence from cells stained with either propidium iodide (PI) or DAPI, which together suggest that the cysts were formed asexually. All evidences led to a conclusion that E. voratum is capable of producing asexual resting cysts, although its sexuality cannot be completely excluded, which guarantees a more intensive investigation. This work fills a gap in the knowledge about the life cycle, particularly the potential of resting cyst formation, of the species in Symbiodiniaceae, a group of dinoflagellates having unique life forms and vital significance in the ecology of coral reefs, and may provide novel insights into understanding the recovery mechanisms of coral reefs destructed by the global climate change and suggest various forms of resting cysts in the cyst assemblages of dinoflagellates observed in the field sediments, including HABs-causing species.
关键词	Asexual resting cyst Effrenium voratum Fluorescence in situ hybridization (fish) Life cycle Single -cyst PCR sequencing
DOI	10.1016/j.hal.2024.102658
收录类别	SCI
语种	英语
资助项目	Field Stations of the Chinese Academy of Science[KFJ-SW-YW047]
WOS研究方向	Marine & Freshwater Biology
WOS类目	Marine & Freshwater Biology
WOS记录号	WOS:001254154300001
出版者	ELSEVIER
WOS关键词	ALEXANDRIUM DINOPHYCEAE ; PHYLOGENETIC ANALYSIS ; GONYAULAX-TAMARENSIS ; CORAL-REEFS ; LIFE-CYCLE ; DINOFLAGELLATE ; IDENTIFICATION ; ZOOXANTHELLAE ; MORPHOLOGY ; CARBON
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/186480
专题	海洋生态与环境科学重点实验室
通讯作者	Chai, Zhaoyang; Tang, Ying Zhong
作者单位	1.Chinese Acad Sci Qingdao, Inst Oceanol, CAS Key Lab Marine Ecol & Environm Sci, Qingdao 266071, Peoples R China 2.Qingdao Marine Sci & Technol Ctr, Lab Marine Ecol & Environm Sci, Qingdao 266237, Shandong, Peoples R China 3.Chinese Acad Sci, Ctr Ocean Mega Sci, Qingdao 266071, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
第一作者单位	中国科学院海洋研究所
通讯作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Li, Ruoxi,Deng, Yunyan,Shang, Lixia,et al. Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae)[J]. HARMFUL ALGAE,2024,137:16.
APA	Li, Ruoxi.,Deng, Yunyan.,Shang, Lixia.,Liu, Yuyang.,Tao, Zhe.,...&Tang, Ying Zhong.(2024).Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae).HARMFUL ALGAE,137,16.
MLA	Li, Ruoxi,et al."Evidence for the production of asexual resting cysts in a free-living species of Symbiodiniaceae (Dinophyceae)".HARMFUL ALGAE 137(2024):16.