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Garric S, Ratin M, Marie D, Foulon V, Probert I, Rodriguez F, Six C. Impaired photoacclimation in a kleptoplastidic dinoflagellate reveals physiological limits of early stages of endosymbiosis. Curr Biol 2024; 34:3064-3076.e5. [PMID: 38936366 DOI: 10.1016/j.cub.2024.05.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/02/2024] [Accepted: 05/29/2024] [Indexed: 06/29/2024]
Abstract
Dinophysis dinoflagellates are predators of Mesodinium ciliates, from which they retain only the plastids of cryptophyte origin. The absence of nuclear photosynthetic cryptophyte genes in Dinophysis raises intriguing physiological and evolutionary questions regarding the functional dynamics of these temporary kleptoplastids within a foreign cellular environment. In an experimental setup including two light conditions, the comparative analysis with Mesodinium rubrum and the cryptophyte Teleaulax amphioxeia revealed that Dinophysis acuminata possessed a smaller and less dynamic functional photosynthetic antenna for green light, a function performed by phycoerythrin. We showed that the lack of the cryptophyte nucleus prevented the synthesis of the phycoerythrin α subunit, thereby hindering the formation of a complete phycoerythrin in Dinophysis. In particular, biochemical analyses showed that Dinophysis acuminata synthesized a poorly stable, incomplete phycoerythrin composed of chromophorylated β subunits, with impaired performance. We show that, consequently, a continuous supply of new plastids is crucial for growth and effective photoacclimation in this organism. Transcriptome analyses revealed that all examined strains of Dinophysis spp. have acquired the cryptophyte pebA and pebB genes through horizontal gene transfer, suggesting a potential ability to synthesize the phycobilin pigments bound to the cryptophyte phycoerythrin. By emphasizing that a potential long-term acquisition of the cryptophyte plastid relies on establishing genetic independence for essential functions such as light harvesting, this study highlights the intricate molecular challenges inherent in the enslavement of organelles and the processes involved in the diversification of photosynthetic organisms through endosymbiosis.
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Affiliation(s)
- Sarah Garric
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, Place Georges Teissier, Roscoff 29680, France
| | - Morgane Ratin
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, Place Georges Teissier, Roscoff 29680, France
| | - Dominique Marie
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, Place Georges Teissier, Roscoff 29680, France
| | - Valentin Foulon
- Centre National de la Recherche Scientifique, UMR 6285 Laboratoire des Sciences et Techniques de l'information de la Communication et de la Connaissance (Lab-STICC), Technopole Brest-Iroise, Brest 29238, France
| | - Ian Probert
- Sorbonne Université, FR 2424, Station Biologique de Roscoff, Place Georges Teissier, Roscoff 29680, France
| | - Francisco Rodriguez
- Centro oceanográfico de Vigo (IEO-CSIC), Subida a Radio Faro 50, Vigo 36390, Spain
| | - Christophe Six
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, Place Georges Teissier, Roscoff 29680, France.
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Song Q, Zhao F, Hou L, Miao M. Cellular interactions and evolutionary origins of endosymbiotic relationships with ciliates. THE ISME JOURNAL 2024; 18:wrae117. [PMID: 38916437 PMCID: PMC11253213 DOI: 10.1093/ismejo/wrae117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/26/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
As unicellular predators, ciliates engage in close associations with diverse microbes, laying the foundation for the establishment of endosymbiosis. Originally heterotrophic, ciliates demonstrate the ability to acquire phototrophy by phagocytizing unicellular algae or by sequestering algal plastids. This adaptation enables them to gain photosynthate and develop resistance to unfavorable environmental conditions. The integration of acquired phototrophy with intrinsic phagotrophy results in a trophic mode known as mixotrophy. Additionally, ciliates can harbor thousands of bacteria in various intracellular regions, including the cytoplasm and nucleus, exhibiting species specificity. Under prolonged and specific selective pressure within hosts, bacterial endosymbionts evolve unique lifestyles and undergo particular reductions in metabolic activities. Investigating the research advancements in various endosymbiotic cases within ciliates will contribute to elucidate patterns in cellular interaction and unravel the evolutionary origins of complex traits.
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Affiliation(s)
- Qi Song
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
| | - Fangqing Zhao
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
- Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1 Xiangshan Road, Hangzhou 310024, China
| | - Lina Hou
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
| | - Miao Miao
- Medical School, University of Chinese Academy of Sciences, No. 1 Yanqihu East Road, Huairou District, Beijing 100049, China
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Johnson MD, Moeller HV, Paight C, Kellogg RM, McIlvin MR, Saito MA, Lasek-Nesselquist E. Functional control and metabolic integration of stolen organelles in a photosynthetic ciliate. Curr Biol 2023; 33:973-980.e5. [PMID: 36773606 DOI: 10.1016/j.cub.2023.01.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/15/2022] [Accepted: 01/16/2023] [Indexed: 02/12/2023]
Abstract
Stealing prey plastids for metabolic gain is a common phenomenon among protists within aquatic ecosystems.1 Ciliates of the Mesodinium rubrum species complex are unique in that they also steal a transcriptionally active but non-dividing prey nucleus, the kleptokaryon, from certain cryptophytes.2 The kleptokaryon enables full control and replication of kleptoplastids but has a half-life of about 10 days.2 Once the kleptokaryon is lost, the ciliate experiences a slow loss of photosynthetic metabolism and eventually death.2,3,4 This transient ability to function phototrophically allows M. rubrum to form productive blooms in coastal waters.5,6,7,8 Here, we show, using multi-omics approaches, that an Antarctic strain of the ciliate not only depends on stolen Geminigera cryophila organelles for photosynthesis but also for anabolic synthesis of fatty acids, amino acids, and other essential macromolecules. Transcription of diverse pathways was higher in the kleptokaryon than that in G. cryophila, and many increased in higher light. Proteins of major biosynthetic pathways were found in greater numbers in the kleptokaryon relative to M. rubrum, implying anabolic dependency on foreign metabolism. We show that despite losing transcriptional control of the kleptokaryon, M. rubrum regulates kleptoplastid pigments with changing light, implying an important role for post-transcriptional control. These findings demonstrate that the integration of foreign organelles and their gene and protein expression, energy metabolism, and anabolism occur in the absence of a stable endosymbiotic association. Our results shed light on potential events early in the process of complex plastid acquisition and broaden our understanding of symbiogenesis.
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Affiliation(s)
- Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - Holly V Moeller
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Christopher Paight
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Riss M Kellogg
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Matthew R McIlvin
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Mak A Saito
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
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Limits to the cellular control of sequestered cryptophyte prey in the marine ciliate Mesodinium rubrum. THE ISME JOURNAL 2021; 15:1056-1072. [PMID: 33230263 PMCID: PMC8115319 DOI: 10.1038/s41396-020-00830-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/28/2020] [Accepted: 11/02/2020] [Indexed: 01/29/2023]
Abstract
The marine ciliate Mesodinium rubrum is famous for its ability to acquire and exploit chloroplasts and other cell organelles from some cryptophyte algal species. We sequenced genomes and transcriptomes of free-swimming Teleaulax amphioxeia, as well as well-fed and starved M. rubrum in order to understand cellular processes upon sequestration under different prey and light conditions. From its prey, the ciliate acquires the ability to photosynthesize as well as the potential to metabolize several essential compounds including lysine, glycan, and vitamins that elucidate its specific prey dependency. M. rubrum does not express photosynthesis-related genes itself, but elicits considerable transcriptional control of the acquired cryptophyte organelles. This control is limited as light-dependent transcriptional changes found in free-swimming T. amphioxeia got lost after sequestration. We found strong transcriptional rewiring of the cryptophyte nucleus upon sequestration, where 35% of the T. amphioxeia genes were significantly differentially expressed within well-fed M. rubrum. Qualitatively, 68% of all genes expressed within well-fed M. rubrum originated from T. amphioxeia. Quantitatively, these genes contributed up to 48% to the global transcriptome in well-fed M. rubrum and down to 11% in starved M. rubrum. This tertiary endosymbiosis system functions for several weeks, when deprived of prey. After this point in time, the ciliate dies if not supplied with fresh prey cells. M. rubrum represents one evolutionary way of acquiring photosystems from its algal prey, and might represent a step on the evolutionary way towards a permanent tertiary endosymbiosis.
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Liu L, Hu L, Yang L, Jia S, Du P, Min X, Wu J, Wu H, Long H, Lu Q, Zhao M. UHRF1 downregulation promotes T follicular helper cell differentiation by increasing BCL6 expression in SLE. Clin Epigenetics 2021; 13:31. [PMID: 33568199 PMCID: PMC7874639 DOI: 10.1186/s13148-021-01007-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/06/2021] [Indexed: 11/16/2022] Open
Abstract
Background Transcription factor B cell lymphoma 6 (BCL6) is a master regulator of T follicular helper (Tfh) cells, which play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms by which BCL6 expression is regulated are poorly understood. Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an important epigenetic factor that regulates DNA methylation and histone modifications. In the present study, we assessed whether UHRF1 can regulate BCL6 expression and influence the differentiation and proliferation of Tfh cells. Results Compared to healthy controls, the mean fluorescence intensity of UHRF1 (UHRF1-MFI) in Tfh cells from SLE patients was significantly downregulated, whereas that of BCL6 (BCL6-MFI) was significantly upregulated. In vitro, UHRF1 knockdown led to BCL6 overexpression and promoted Tfh cell differentiation. In contrast, UHRF1 overexpression led to BCL6 downregulation and decreased Tfh cell differentiation. In vivo, conditional UHRF1 gene knockout (UHRF1-cKO) in mouse T cells revealed that UHRF1 depletion can enhance the proportion of Tfh cells and induce an augmented GC reaction in mice treated with NP-keyhole limpet hemocyanin (NP-KLH). Mechanistically, UHRF1 downregulation can decrease DNA methylation and H3K27 trimethylation (H3K27me3) levels in the BCL6 promoter region of Tfh cells. Conclusions Our results demonstrated that UHRF1 downregulation leads to increased BCL6 expression by decreasing DNA methylation and H3K27me3 levels, promoting Tfh cell differentiation in vitro and in vivo. This finding reveals the role of UHRF1 in regulating Tfh cell differentiation and provides a potential target for SLE therapy.
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Affiliation(s)
- Limin Liu
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Longyuan Hu
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Linxuan Yang
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Sujie Jia
- Department of Pharmacy, Central South University, The Third Xiangya Hospital, Changsha, China
| | - Pei Du
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Xiaoli Min
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Jiali Wu
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Haijing Wu
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Hai Long
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Qianjin Lu
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China.,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China
| | - Ming Zhao
- Department of Dermatology, Second Xiangya Hospital, Central South University, #139 Renmin Middle Road, Changsha, 410011, Hunan, China. .,Research Unit of Key Technologies of Diagnosis and Treatment for Immune-Related Skin Diseases, Chinese Academy of Medical Sciences (2019RU027), Changsha, Hunan, China.
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6
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Onuma R, Hirooka S, Kanesaki Y, Fujiwara T, Yoshikawa H, Miyagishima SY. Changes in the transcriptome, ploidy, and optimal light intensity of a cryptomonad upon integration into a kleptoplastic dinoflagellate. THE ISME JOURNAL 2020; 14:2407-2423. [PMID: 32514116 PMCID: PMC7490267 DOI: 10.1038/s41396-020-0693-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 11/30/2022]
Abstract
Endosymbiosis of unicellular eukaryotic algae into previously nonphotosynthetic eukaryotes has established chloroplasts in several eukaryotic lineages. In addition, certain unicellular organisms in several different lineages ingest algae and utilize them as temporal chloroplasts (kleptoplasts) for weeks to months before digesting them. Among these organisms, the dinoflagellate Nusuttodinium aeruginosum ingests the cryptomonad Chroomonas sp. and enlarges the kleptoplast with the aid of the cryptomonad nucleus. To understand how the cryptomonad nucleus is remodeled in the dinoflagellate, here we examined changes in the transcriptome and ploidy of the ingested nucleus. We show that, after ingestion, genes involved in metabolism, translation, and DNA replication are upregulated while those involved in sensory systems and cell motility are downregulated. In the dinoflagellate cell, the cryptomonad nucleus undergoes polyploidization that correlates with an increase in the mRNA levels of upregulated genes. In addition, the ingested nucleus almost loses transcriptional responses to light. Because polyploidization and loss of transcriptional regulation are also known to have occurred during the establishment of endosymbiotic organelles, these changes are probably a common trend in endosymbiotic evolution. Furthermore, we show that the kleptoplast and dinoflagellate are more susceptible to high light than the free-living cryptomonad but that the ingested nucleus reduces this damage.
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Affiliation(s)
- Ryo Onuma
- Department of Gene Function and Phenomics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka, 411-8540, Japan.
| | - Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka, 411-8540, Japan
| | - Yu Kanesaki
- Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga, Shizuoka, 422-8529, Japan
| | - Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Yata 1111, Mishima, Shizuoka, 411-8540, Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo, 156-8502, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Yata 1111, Mishima, Shizuoka, 411-8540, Japan.
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Fiorendino JM, Smith JL, Campbell L. Growth response of Dinophysis, Mesodinium, and Teleaulax cultures to temperature, irradiance, and salinity. HARMFUL ALGAE 2020; 98:101896. [PMID: 33129454 DOI: 10.1016/j.hal.2020.101896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Mixotrophic Dinophysis species threaten human health and coastal economies through the production of toxins which cause diarrhetic shellfish poisoning (DSP) in humans. Novel blooms of Dinophysis acuminata and Dinophysis ovum have occurred in North American waters in recent decades, resulting in the closure of shellfish harvesting. Understanding the ecology of Dinophysis species and their prey is essential to predicting and mitigating the impact of blooms of these dinoflagellates. The growth response of two new isolates of Dinophysis species, one isolate of Mesodinium rubrum, and two strains of Teleaulax amphioxeia were evaluated at a range of temperature, salinity, and irradiance treatments to identify possible environmental drivers of Dinophysis blooms in the Gulf of Mexico. Results showed optimal growth of T. amphioxeia and M. rubrum at 24 °C, salinity 30 - 34, and irradiances between 300 and 400 µmol quanta m - 2s - 1. Optimal Dinophysis growth was observed at salinity 22 and temperatures between 18 and 24 °C. Mesodinium and both Dinophysis responded differently to experimental treatments, which may be due to the suitability of prey and different handling of kleptochloroplasts. Dinophysis bloom onset may be initiated by warming surface waters between winter and spring in the Gulf of Mexico. Toxin profiles for these two North American isolates were distinct; Dinophysis acuminata produced okadaic acid, dinophysistoxin-1, and pectenotoxin-2 while D. ovum produced only okadaic acid. Toxin per cell for D. ovum was two orders of magnitude greater than D. acuminata. Phylogenies based on the cox1 and cob genes did not distinguish these two Dinophysis species within the D. acuminata complex.
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Affiliation(s)
- James M Fiorendino
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Juliette L Smith
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, Virginia, 23062, USA
| | - Lisa Campbell
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA.
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Nomura M, Kamikawa R, Ishida KI. Fine Structure Observation of Feeding Behavior, Nephroselmis spp.-derived Chloroplast Enlargement, and Mitotic Processes in the Katablepharid Hatena arenicola. Protist 2020; 171:125714. [PMID: 32088560 DOI: 10.1016/j.protis.2020.125714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/19/2020] [Accepted: 01/21/2020] [Indexed: 11/17/2022]
Abstract
The difficult-to-cultivate katablepharid Hatena arenicola ingests green algae, Nephroselmis spp., and temporarily retains a Nephroselmis-derived cell compartment (kleptochloroplast), including a chloroplast within a phagocytotic vacuole. H. arenicola has a unique life history; during cell division, the Nephroselmis-derived cell compartment is only inherited by one of two daughter cells. However, the detailed morphological transition of the Nephroselmis cell to a kleptochloroplast and the mitotic process of the host cell remain unclear. Herein, we observed feeding behavior, enlargement of the Nephroselmis-derived chloroplast, and mitotic processes in H. arenicola using light and electron microscopy. During feeding behavior, H. arenicola peeled off the cell coverings and flagella of the Nephroselmis cell, which selectively accumulated in a vacuole separate to one containing a Nephroselmis cell body. An obvious nucleolus, but no heterochromatin was observed in the Nephroselmis-derived nucleus during the chloroplast-enlarging process, while compressed heterochromatin was explicitly observed in the nuclei of free-living Nephroselmis cells. The cell membrane of an ingested Nephroselmis cell disintegrated during enlargement of the Nephroselmis-derived chloroplast. The process of mitosis in H. arenicola was very similar to that of other katablepharids and cryptophytes.
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Affiliation(s)
- Mami Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida, Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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Liu Q, Xing Y, Li Y, Wang H, Mi T, Zhen Y, Yu Z. Carbon fixation gene expression in Skeletonema marinoi in nitrogen-, phosphate-, silicate-starvation, and low-temperature stress exposure. JOURNAL OF PHYCOLOGY 2020; 56:310-323. [PMID: 31628865 DOI: 10.1111/jpy.12936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 10/10/2019] [Indexed: 06/10/2023]
Abstract
Diatoms are unicellular algae with a set of extraordinary genes, metabolic pathways, and physiological functions acquired by secondary endosymbiosis, especially for their efficient photosynthetic carbon fixation mechanisms, which can be a reason for their successful environmental adaptation and great contribution to primary production. Based on the available genomic information, the expression patterns of carbon fixation genes were analyzed using transcriptomic sequencing and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in Skeletonema marinoi. Meanwhile, suitable reference genes applying to specific experimental treatments were selected. In our results, carbon fixation genes were standardized by actin and TATA box-binding protein-coding genes in growth phase samples and stress conditions, respectively. It was found that a series of carbon fixation genes, such as the pyruvate orthophosphate dikinase (PPDK)-coding gene, had significantly up-regulated expression in nitrogen-starvation, phosphate-starvation, and low-temperature conditions, but consistently down-regulated in silicate-starvation treatment. These carbon fixation genes exhibited variable expression levels in different conditions and will be useful for investigating gene expression mechanisms in S. marinoi and improve our understanding of diatom carbon fixation pathways.
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Affiliation(s)
- Qian Liu
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Yongze Xing
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Sciences Academy, Beihai, 536000, China
| | - Ying Li
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Hualong Wang
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Tiezhu Mi
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Yu Zhen
- Key laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Zhigang Yu
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
- Key Laboratory of Marine Chemical Theory and Technology, Ministry of Education, Qingdao, 266100, China
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Lasek-Nesselquist E, Johnson MD. A Phylogenomic Approach to Clarifying the Relationship of Mesodinium within the Ciliophora: A Case Study in the Complexity of Mixed-Species Transcriptome Analyses. Genome Biol Evol 2019; 11:3218-3232. [PMID: 31665294 PMCID: PMC6859813 DOI: 10.1093/gbe/evz233] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2019] [Indexed: 11/25/2022] Open
Abstract
Recent high-throughput sequencing endeavors have yielded multigene/protein phylogenies that confidently resolve several inter- and intra-class relationships within the phylum Ciliophora. We leverage the massive sequencing efforts from the Marine Microbial Eukaryote Transcriptome Sequencing Project, other SRA submissions, and available genome data with our own sequencing efforts to determine the phylogenetic position of Mesodinium and to generate the most taxonomically rich phylogenomic ciliate tree to date. Regardless of the data mining strategy, the multiprotein data set, or the molecular models of evolution employed, we consistently recovered the same well-supported relationships among ciliate classes, confirming many of the higher-level relationships previously identified. Mesodinium always formed a monophyletic group with members of the Litostomatea, with mixotrophic species of Mesodinium-M. rubrum, M. major, and M. chamaeleon-being more closely related to each other than to the heterotrophic member, M. pulex. The well-supported position of Mesodinium as sister to other litostomes contrasts with previous molecular analyses including those from phylogenomic studies that exploited the same transcriptomic databases. These topological discrepancies illustrate the need for caution when mining mixed-species transcriptomes and indicate that identifying ciliate sequences among prey contamination-particularly for Mesodinium species where expression from stolen prey nuclei appears to dominate-requires thorough and iterative vetting with phylogenies that incorporate sequences from a large outgroup of prey.
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Affiliation(s)
| | - Matthew D Johnson
- Biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
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11
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Kim M, Park MG. Unveiling the hidden genetic diversity and chloroplast type of marine benthic ciliate Mesodinium species. Sci Rep 2019; 9:14081. [PMID: 31575940 PMCID: PMC6773952 DOI: 10.1038/s41598-019-50659-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Abstract
Ciliate Mesodinium species are commonly distributed in diverse aquatic systems worldwide. Among Mesodinium species, M. rubrum is closely associated with microbial food webs and red tide formation and is known to acquire chloroplasts from its cryptophyte prey for use in photosynthesis. For these reasons, Mesodinium has long received much attention in terms of ecophysiology and chloroplast evolution. Mesodinium cells are easily identifiable from other organisms owing to their unique morphology comprising two hemispheres, but a clear distinction among species is difficult under a microscope. Recent taxonomic studies of Mesodinium have been conducted largely in parallel with molecular sequence analysis, and the results have shown that the best-known planktonic M. rubrum in fact comprises eight genetic clades of a M. rubrum/M. major complex. However, unlike the planktonic Mesodinium species, little is known of the genetic diversity of benthic Mesodinium species, and to our knowledge, the present study is the first to explore this. A total of ten genetic clades, including two clades composed of M. chamaeleon and M. coatsi, were found in marine sandy sediments, eight of which were clades newly discovered through this study. We report the updated phylogenetic relationship within the genus Mesodinium comprising heterotrophic/mixotrophic as well as planktonic/benthic species. Furthermore, we unveiled the wide variety of chloroplasts of benthic Mesodinium, which were related to the green cryptophyte Chroomonas/Hemiselmis and the red cryptophyte Rhodomonas/Storeatula/Teleaulax groups.
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Affiliation(s)
- Miran Kim
- Research Institute for Basic Science, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Myung Gil Park
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Republic of Korea.
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Prey Lysate Enhances Growth and Toxin Production in an Isolate of Dinophysis acuminata. Toxins (Basel) 2019; 11:toxins11010057. [PMID: 30669577 PMCID: PMC6356360 DOI: 10.3390/toxins11010057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 11/24/2022] Open
Abstract
The physiological and toxicological characteristics of Dinophysis acuminata have been increasingly studied in an attempt to better understand and predict diarrhetic shellfish poisoning (DSP) events worldwide. Recent work has identified prey quantity, organic nitrogen, and ammonium as likely contributors to increased Dinophysis growth rates and/or toxicity. Further research is now needed to better understand the interplay between these factors, for example, how inorganic and organic compounds interact with prey and a variety of Dinophysis species and/or strains. In this study, the exudate of ciliate prey and cryptophytes were investigated for an ability to support D. acuminata growth and toxin production in the presence and absence of prey, i.e., during mixotrophic and phototrophic growth respectively. A series of culturing experiments demonstrated that the addition of ciliate lysate led to faster dinoflagellate growth rates (0.25 ± 0.002/d) in predator-prey co-incubations than in treatments containing (1) similar levels of prey but without lysate (0.21 ± 0.003/d), (2) ciliate lysate but no live prey (0.12 ± 0.004/d), or (3) monocultures of D. acuminata without ciliate lysate or live prey (0.01 ± 0.007/d). The addition of ciliate lysate to co-incubations also resulted in maximum toxin quotas and extracellular concentrations of okadaic acid (OA, 0.11 ± 0.01 pg/cell; 1.37 ± 0.10 ng/mL) and dinophysistoxin-1 (DTX1, 0.20 ± 0.02 pg/cell; 1.27 ± 0.10 ng/mL), and significantly greater total DSP toxin concentrations (intracellular + extracellular). Pectenotoxin-2 values, intracellular or extracellular, did not show a clear trend across the treatments. The addition of cryptophyte lysate or whole cells, however, did not support dinoflagellate cell division. Together these data demonstrate that while certain growth was observed when only lysate was added, the benefits to Dinophysis were maximized when ciliate lysate was added with the ciliate inoculum (i.e., during mixotrophic growth). Extrapolating to the field, these culturing studies suggest that the presence of ciliate exudate during co-occurring dinoflagellate-ciliate blooms may indirectly and directly exacerbate D. acuminata abundance and toxigenicity. More research is required, however, to understand what direct or indirect mechanisms control the predator-prey dynamic and what component(s) of ciliate lysate are being utilized by the dinoflagellate or other organisms (e.g., ciliate or bacteria) in the culture if predictive capabilities are to be developed and management strategies created.
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Kim M, Kang M, Park MG. Growth and Chloroplast Replacement of the Benthic Mixotrophic Ciliate Mesodinium coatsi. J Eukaryot Microbiol 2019; 66:625-636. [PMID: 30561091 PMCID: PMC6766864 DOI: 10.1111/jeu.12709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 09/27/2018] [Accepted: 12/06/2018] [Indexed: 01/14/2023]
Abstract
While the ecophysiology of planktonic Mesodinium rubrum species complex has been relatively well studied, very little is known about that of benthic Mesodinium species. In this study, we examined the growth response of the benthic ciliate Mesodinium coatsi to different cryptophyte prey using an established culture of this species. M. coatsi was able to ingest all of the offered cryptophyte prey types, but not all cryptophytes supported its positive, sustained growth. While M. coatsi achieved sustained growth on all of the phycocyanin‐containing Chroomonas spp. it was offered, it showed different growth responses to the phycoerythrin‐containing cryptophytes Rhodomonas spp., Storeatula sp., and Teleaulax amphioxeia. M. coatsi was able to easily replace previously ingested prey chloroplasts with newly ingested ones within 4 d, irrespective of prey type, if cryptophyte prey were available. Once retained, the ingested prey chloroplasts seemed to be photosynthetically active. When fed, M. coatsi was capable of heterotrophic growth in darkness, but its growth was enhanced significantly in the light (14:10 h light:dark cycle), suggesting that photosynthesis by ingested prey chloroplast leads to a significant increase in the growth of M. coatsi. Our results expand the knowledge of autecology and ecophysiology of the benthic M. coatsi.
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Affiliation(s)
- Miran Kim
- Research Institute for Basic Science, Chonnam National University, Gwangju, 61186, Korea
| | - Misun Kang
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Korea
| | - Myung Gil Park
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju, 61186, Korea
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García-Portela M, Reguera B, Sibat M, Altenburger A, Rodríguez F, Hess P. Metabolomic Profiles of Dinophysis acuminata and Dinophysis acuta Using Non-Targeted High-Resolution Mass Spectrometry: Effect of Nutritional Status and Prey. Mar Drugs 2018; 16:E143. [PMID: 29701702 PMCID: PMC5982093 DOI: 10.3390/md16050143] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/11/2018] [Accepted: 04/20/2018] [Indexed: 11/24/2022] Open
Abstract
Photosynthetic species of the genus Dinophysis are obligate mixotrophs with temporary plastids (kleptoplastids) that are acquired from the ciliate Mesodinium rubrum, which feeds on cryptophytes of the Teleaulax-Plagioselmis-Geminigera clade. A metabolomic study of the three-species food chain Dinophysis-Mesodinium-Teleaulax was carried out using mass spectrometric analysis of extracts of batch-cultured cells of each level of that food chain. The main goal was to compare the metabolomic expression of Galician strains of Dinophysis acuminata and D. acuta that were subjected to different feeding regimes (well-fed and prey-limited) and feeding on two Mesodinium (Spanish and Danish) strains. Both Dinophysis species were able to grow while feeding on both Mesodinium strains, although differences in growth rates were observed. Toxin and metabolomic profiles of the two Dinophysis species were significantly different, and also varied between different feeding regimes and different prey organisms. Furthermore, significantly different metabolomes were expressed by a strain of D. acuminata that was feeding on different strains of the ciliate Mesodinium rubrum. Both species-specific metabolites and those common to D. acuminata and D. acuta were tentatively identified by screening of METLIN and Marine Natural Products Dictionary databases. This first metabolomic study applied to Dinophysis acuminata and D.acuta in culture establishes a basis for the chemical inventory of these species.
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Affiliation(s)
| | - Beatriz Reguera
- IEO, Oceanographic Centre of Vigo, Subida a Radio Faro 50, Vigo 36390, Spain.
| | - Manoella Sibat
- IFREMER, Phycotoxins Laboratory, rue de l'Ile d'Yeu, BP 21105, F-44311 Nantes, France.
| | - Andreas Altenburger
- Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark.
| | - Francisco Rodríguez
- IEO, Oceanographic Centre of Vigo, Subida a Radio Faro 50, Vigo 36390, Spain.
| | - Philipp Hess
- IFREMER, Phycotoxins Laboratory, rue de l'Ile d'Yeu, BP 21105, F-44311 Nantes, France.
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Moeller HV, Johnson MD. Preferential Plastid Retention by the Acquired Phototroph Mesodinium chamaeleon. J Eukaryot Microbiol 2017; 65:148-158. [PMID: 28710891 DOI: 10.1111/jeu.12446] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/15/2017] [Accepted: 07/06/2017] [Indexed: 11/29/2022]
Abstract
The ciliate genus Mesodinium contains species that rely to varying degrees on photosynthetic machinery stolen from cryptophyte algal prey. Prey specificity appears to scales inversely with this reliance: The predominantly phototrophic M. major/rubrum species complex exhibits high prey specificity, while the heterotrophic lineages M. pulex and pupula are generalists. Here, we test the hypothesis that the recently described mixotroph M. chamaeleon, which is phylogenetically intermediate between M. major/rubrum and M. pulex/pupula, exhibits intermediate prey preferences. Using a series of feeding and starvation experiments, we demonstrate that M. chamaeleon grazes and retains plastids at rates which often exceed those observed in M. rubrum, and retains plastids from at least five genera of cryptophyte algae. Despite this relative generality, M. chamaeleon exhibits distinct prey preferences, with higher plastid retention, mixotrophic growth rates and efficiencies, and starvation tolerance when offered Storeatula major, a cryptophyte that M. rubrum does not appear to ingest. These results suggest that niche partitioning between the two acquired phototrophs may be mediated by prey identity. M. chamaeleon appears to represent an intermediate step in the transition to strict reliance on acquired phototrophy, indicating that prey specificity may evolve alongside degree of phototrophy.
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Affiliation(s)
- Holly V Moeller
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.,Department of Ecology, Evolution, & Marine Biology, University of California, Santa Barbara, Santa Barbara, California, 93106, USA.,Biodiversity Research Centre, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA
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Bodył A. Did some red alga-derived plastids evolveviakleptoplastidy? A hypothesis. Biol Rev Camb Philos Soc 2017; 93:201-222. [DOI: 10.1111/brv.12340] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 04/24/2017] [Accepted: 04/25/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Andrzej Bodył
- Laboratory of Evolutionary Protistology, Department of Invertebrate Biology, Evolution and Conservation, Institute of Environmental Biology; University of Wrocław, ul. Przybyszewskiego 65; 51-148 Wrocław Poland
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Kim M, Drumm K, Daugbjerg N, Hansen PJ. Dynamics of Sequestered Cryptophyte Nuclei in Mesodinium rubrum during Starvation and Refeeding. Front Microbiol 2017; 8:423. [PMID: 28377747 PMCID: PMC5359308 DOI: 10.3389/fmicb.2017.00423] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/28/2017] [Indexed: 11/24/2022] Open
Abstract
The marine mixotrophic ciliate Mesodinium rubrum is known to acquire chloroplasts, mitochondria, nucleomorphs, and nucleus from its cryptophyte prey, particularly from species in the genera, Geminigera and Teleaulax. The sequestered prey nucleus and chloroplasts are considered to support photosynthesis of M. rubrum. In addition, recent studies have shown enlargement of the retained prey nucleus in starved M. rubrum and have inferred that enlargement results from the fusion of ingested prey nuclei. Thus far, however, little is known about the mechanism underlying the enlargement of the prey nucleus in M. rubrum. Here, we conducted starvation and refeeding studies to monitor the fate of prey nuclei acquired by M. rubrum when feeding on Teleaulax amphioxeia and to explore the influence of the retained prey nucleus on photosynthesis of M. rubrum. Results indicate that enlargement of the prey nucleus does not result from fusion of nuclei. Furthermore, the enlarged prey nucleus does not appear to divide during cell division of M. rubrum. The presence of a prey nucleus significantly affected photosynthetic performance of M. rubrum, while the number of retained chloroplasts had little influence on rate of carbon fixation. We interpret results within the context of a model that considers the dynamics of ingested prey nuclei during division of M. rubrum.
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Affiliation(s)
- Miran Kim
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
| | - Kirstine Drumm
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
| | - Niels Daugbjerg
- Marine Biological Section, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Per J Hansen
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
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Reply to Johnson et al.: Functionally active cryptophyte cell membrane and cytoplasm indicate intact symbionts within Mesodinium. Proc Natl Acad Sci U S A 2017; 114:E1043-E1044. [PMID: 28154147 DOI: 10.1073/pnas.1620409114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Nam SW, Park JW, Yih W, Park MG, Shin W. The fate of cryptophyte cell organelles in the ciliate Mesodinium cf. rubrum subjected to starvation. HARMFUL ALGAE 2016; 59:19-30. [PMID: 28073503 DOI: 10.1016/j.hal.2016.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/11/2016] [Accepted: 09/14/2016] [Indexed: 06/06/2023]
Abstract
Mesodinium rubrum Lohmann is a mixotrophic ciliate and one of the best studied species exhibiting acquired phototrophy. To investigate the fate of cryptophyte organelles in the ciliate subjected to starvation, we conducted ultrastructural studies of a Korean strain of M. cf. rubrum during a 10 week starvation experiments. Ingested cells of the cryptophyte Teleaulax amphioxeia were first enveloped by ciliate membrane, and then prey organelles, including ejectisomes, flagella, basal bodies and flagellar roots, were digested. Over time, prey nuclei protruded into the cytoplasm of the ciliate, their size and volume increased, and their number decreased, suggesting that the cryptophyte nuclei likely fused with each other in the ciliate cytoplasm. At 4 weeks of starvation, M. cf. rubrum cells without cryptophyte nuclei started to appear. At 10 weeks of starvation, only two M. cf. rubrum cells still possessing a cryptophyte nucleus had relatively intact chloroplast-mitochondria complexes (CMCs), while M. cf. rubrum cells without cryptophyte nuclei had a few damaged CMCs. This is the first ultrastructural study demonstrating that cryptophyte nuclei undergo a dramatic change inside M. cf. rubrum in terms of size, shape, and number following their acquisition.
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Affiliation(s)
- Seung Won Nam
- Department of Biology, Chungnam National University, Deajeon 34134, Republic of Korea; LOHABE, Department of Oceanography, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jong Woo Park
- Department of Oceanography, Kunsan National University, Kunsan 54150, Republic of Korea; Ocean Climate and Ecology Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea
| | - Wonho Yih
- Department of Oceanography, Kunsan National University, Kunsan 54150, Republic of Korea
| | - Myung Gil Park
- LOHABE, Department of Oceanography, Chonnam National University, Gwangju 61186, Republic of Korea.
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Deajeon 34134, Republic of Korea.
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