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PLASTID DYNAMICS DURING SURVIVAL OF DINOPHYSIS CAUDATA WITHOUT ITS CILIATE PREY 1
Author(s) -
Park Myung Gil,
Park Jong Soo,
Kim Miran,
Yih Wonho
Publication year - 2008
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.2008.00579.x
Subject(s) - caudata , biology , dinophysis , plastid , photosynthesis , botany , ecology , chloroplast , gene , genetics , phytoplankton , nutrient , algal bloom
To survive, the marine dinoflagellate Dinophysis caudata Saville‐Kent must feed on the plastidic ciliate Myrionecta rubra (= Mesodinium rubrum ), itself a consumer of cryptophytes . Whether D . caudata has its own permanent chloroplasts or retains plastids from its ciliate prey, however, remains unresolved. Further, how long D . caudata plastids (or kleptoplastids) persist and remain photosynthetically active in the absence of prey remains unknown. We addressed those issues here, using the first established culture of D . caudata . Phylogenetic analyses of the plastid 16S rRNA and psb A gene sequences directly from the three organisms ( D . caudata , M . rubra , and a cryptophyte) revealed that the sequences of both genes from the three organisms are almost identical to each other, supporting that the plastids of D . caudata are kleptoplastids. A 3‐month starvation experiment revealed that D . caudata can remain photosynthetically active for ∼2 months when not supplied with prey. D . caudata cells starved for more than 2 months continued to keep the plastid 16S rRNA gene but lost the photosynthesis‐related genes (i.e., psa A and psb A genes). When the prey was available again, however, D . caudata cells starved for more than 2 months were able to reacquire plastids and slowly resumed photosynthetic activity. Taken all together, the results indicate that the nature of the relationship between D . caudata and its plastids is not that of permanent cellular acquisitions. D . caudata is an intriguing protist that would represent an interesting evolutionary adaptation with regard to photosynthesis as well as help us to better understand plastid evolution in eukaryotes.