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Laetz EMJ, Kahyaoglu C, Borgstein NM, Merkx M, van der Meij SET, Verberk WCEP. Critical thermal maxima and oxygen uptake in Elysia viridis, a sea slug that steals chloroplasts to photosynthesize. J Exp Biol 2024; 227:jeb246331. [PMID: 38629207 DOI: 10.1242/jeb.246331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 03/31/2024] [Indexed: 05/31/2024]
Abstract
Photosynthetic animals produce oxygen, providing an ideal lens for studying how oxygen dynamics influence thermal sensitivity. The algivorous sea slug Elysia viridis can steal and retain chloroplasts from the marine alga Bryopsis sp. for months when starved, but chloroplast retention is mere weeks when they are fed another green alga, Chaetomorpha sp. To examine plasticity in thermal tolerance and changes in net oxygen exchange when fed and starving, slugs fed each alga were acclimated to 17°C (the current maximum temperature to which they are exposed in nature) and 22°C (the increase predicted for 2100) and measured at different points during starvation. We also examined increased illumination to evaluate a potential tradeoff between increased oxygen production but faster chloroplast degradation. Following acclimation, we subjected slugs to acute thermal stress to determine their thermal tolerance. We also measured net oxygen exchange before and after acute thermal stress. Thermal tolerance improved in slugs acclimated to 22°C, indicating they can acclimate to temperatures higher than they naturally experience. All slugs exhibited net oxygen uptake, and rates were highest in recently fed slugs before exposure to acute thermal stress. Oxygen uptake was suppressed following acute thermal stress. Under brighter light, slugs exhibited improved thermal tolerance, possibly because photosynthetic oxygen production alleviated oxygen limitation. Accordingly, this advantage disappeared later in starvation when photosynthesis ceased. Thus, E. viridis can cope with heatwaves by suppressing metabolism and plastically adjusting heat tolerance; however, starvation influences a slug's thermal tolerance and oxygen uptake such that continuous access to algal food for its potential nutritive and oxygenic benefits is critical when facing thermal stress.
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Affiliation(s)
- Elise M J Laetz
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Can Kahyaoglu
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Natascha M Borgstein
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Michiel Merkx
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Sancia E T van der Meij
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, The Netherlands
| | - Wilco C E P Verberk
- Department of Ecology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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2
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Morelli L, Cartaxana P, Cruz S. Food shaped photosynthesis: Photophysiology of the sea slug Elysia viridis fed with two alternative chloroplast donors. OPEN RESEARCH EUROPE 2024; 3:107. [PMID: 38725452 PMCID: PMC11079582 DOI: 10.12688/openreseurope.16162.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/26/2024] [Indexed: 05/12/2024]
Abstract
Background Some Sacoglossa sea slugs steal and integrate chloroplasts derived from the algae they feed on into their cells where they continue to function photosynthetically, a process termed kleptoplasty. The stolen chloroplasts - kleptoplasts - can maintain their functionality up to several months and support animal metabolism. However, chloroplast longevity can vary depending on sea slug species and algal donor. In this study, we focused on Elysia viridis, a polyphagous species that is mostly found associated with the macroalga Codium tomentosum, but that was reported to eat other macroalgae, including Chaetomorpha sp. Methods We have investigated the changes in E. viridis physiology when provided with the two different food sources to evaluate to which extent the photosynthetic and photoprotective mechanisms of the algae chloroplasts matched those of the plastids once in the animal cells. To perform the study, we rely on the evaluation of chlorophyll a variable fluorescence to study the photophysiological state of the integrated kleptoplasts and high-performance liquid chromatography (HPLC) to study variations in the photosynthetic pigments. Results We observed that the photosynthetic efficiency of E. viridis is lower when fed with Chaetomorpha. Also, significant differences were observed in the non-photochemical quenching (NPQ) abilities of the sea slugs. While sea slugs fed with C. tomentosum react similarly to high-light stress as the alga, E. viridis hosting Chaetomorpha chloroplasts were unable to properly recover from photoinhibition or perform a functional xanthophyll cycle (XC). Conclusions Our results showed that, even if the sea slugs fed with the two algae show photosynthetic activities like the respective algal donors, not all the photoprotective mechanisms present in Chaetomorpha can be maintained in E. viridis. This indicates that the functionality of the kleptoplasts does not depend solely on their origin but also on the degree of compatibility with the animal species integrating them.
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Affiliation(s)
- Luca Morelli
- CESAM – Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Aveiro District, 3810-193, Portugal
| | - Paulo Cartaxana
- CESAM – Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Aveiro District, 3810-193, Portugal
| | - Sónia Cruz
- CESAM – Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Aveiro District, 3810-193, Portugal
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3
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Miyagishima SY. Taming the perils of photosynthesis by eukaryotes: constraints on endosymbiotic evolution in aquatic ecosystems. Commun Biol 2023; 6:1150. [PMID: 37952050 PMCID: PMC10640588 DOI: 10.1038/s42003-023-05544-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023] Open
Abstract
An ancestral eukaryote acquired photosynthesis by genetically integrating a cyanobacterial endosymbiont as the chloroplast. The chloroplast was then further integrated into many other eukaryotic lineages through secondary endosymbiotic events of unicellular eukaryotic algae. While photosynthesis enables autotrophy, it also generates reactive oxygen species that can cause oxidative stress. To mitigate the stress, photosynthetic eukaryotes employ various mechanisms, including regulating chloroplast light absorption and repairing or removing damaged chloroplasts by sensing light and photosynthetic status. Recent studies have shown that, besides algae and plants with innate chloroplasts, several lineages of numerous unicellular eukaryotes engage in acquired phototrophy by hosting algal endosymbionts or by transiently utilizing chloroplasts sequestrated from algal prey in aquatic ecosystems. In addition, it has become evident that unicellular organisms engaged in acquired phototrophy, as well as those that feed on algae, have also developed mechanisms to cope with photosynthetic oxidative stress. These mechanisms are limited but similar to those employed by algae and plants. Thus, there appear to be constraints on the evolution of those mechanisms, which likely began by incorporating photosynthetic cells before the establishment of chloroplasts by extending preexisting mechanisms to cope with oxidative stress originating from mitochondrial respiration and acquiring new mechanisms.
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Affiliation(s)
- Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- The Graduate University for Advanced Studies, SOKENDAI, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
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4
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Pinko D, Abramovich S, Rahav E, Belkin N, Rubin-Blum M, Kucera M, Morard R, Holzmann M, Abdu U. Shared ancestry of algal symbiosis and chloroplast sequestration in foraminifera. SCIENCE ADVANCES 2023; 9:eadi3401. [PMID: 37824622 PMCID: PMC10569721 DOI: 10.1126/sciadv.adi3401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/07/2023] [Indexed: 10/14/2023]
Abstract
Foraminifera are unicellular organisms that established the most diverse algal symbioses in the marine realm. Endosymbiosis repeatedly evolved in several lineages, while some engaged in the sequestration of chloroplasts, known as kleptoplasty. So far, kleptoplasty has been documented exclusively in the rotaliid clade. Here, we report the discovery of kleptoplasty in the species Hauerina diversa that belongs to the miliolid clade. The existence of kleptoplasty in the two main clades suggests that it is more widespread than previously documented. We observed chloroplasts in clustered structures within the foraminiferal cytoplasm and confirmed their functionality. Phylogenetic analysis of 18S ribosomal RNA gene sequences showed that H. diversa branches next to symbiont-bearing Alveolinidae. This finding represents evidence of of a relationship between kleptoplastic and symbiotic foraminifera.. Analysis of ribosomal genes and metagenomics revealed that alveolinid symbionts and kleptoplasts belong to the same clade, which suggests a common ancestry.
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Affiliation(s)
- Doron Pinko
- Department of Earth and Environmental Science, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Sigal Abramovich
- Department of Earth and Environmental Science, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Eyal Rahav
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Natalia Belkin
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Maxim Rubin-Blum
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Michal Kucera
- MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Raphaël Morard
- MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Maria Holzmann
- Department of Genetics and Evolution, University of Geneva, Quai Ernest Ansermet 30, Geneva 4 1211, Switzerland
| | - Uri Abdu
- Department of Life Science, Ben-Gurion University of the Negev, Beer Sheva, Israel
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5
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Lopes D, Cruz S, Martins P, Ferreira S, Nunes C, Domingues P, Cartaxana P. Sea Slug Mucus Production Is Supported by Photosynthesis of Stolen Chloroplasts. BIOLOGY 2022; 11:1207. [PMID: 36009836 PMCID: PMC9405057 DOI: 10.3390/biology11081207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
A handful of sea slugs of the order Sacoglossa are able to steal chloroplasts-kleptoplasts-from their algal food sources and maintain them functionally for periods ranging from several weeks to a few months. In this study, we investigated the role of kleptoplast photosynthesis on mucus production by the tropical sea slug Elysia crispata. Animals reared for 5 weeks in quasi dark (5 μmol photons m-2 s-1) showed similar growth to those under regular light (60-90 μmol photons m-2 s-1), showing that kleptoplast photosynthesis was not relevant for growth when sea slugs were fed ad libitum. However, when subjected to short-term desiccation stress, animals reared under regular light produced significantly more mucus. Furthermore, the carbohydrate content of secreted mucus was significantly lower in slugs limited in the photosynthetic activity of their kleptoplasts by quasi-dark conditions. This study indicates that photosynthesis supports the synthesis of protective mucus in kleptoplast-bearing sea slugs.
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Affiliation(s)
- Diana Lopes
- ECOMARE—Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM—Centre for Environmental and Marine Studies, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Sónia Cruz
- ECOMARE, CESAM, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Patrícia Martins
- ECOMARE, CESAM, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Sónia Ferreira
- CICECO—Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Cláudia Nunes
- CICECO, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Pedro Domingues
- Mass Spectrometry Centre, LAQV-REQUIMTE—Associated Laboratory for Green Chemistry of the Network of Chemistry and Technology, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Paulo Cartaxana
- ECOMARE, CESAM, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
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6
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Havurinne V, Aitokari R, Mattila H, Käpylä V, Tyystjärvi E. Ultraviolet screening by slug tissue and tight packing of plastids protect photosynthetic sea slugs from photoinhibition. PHOTOSYNTHESIS RESEARCH 2022; 152:373-387. [PMID: 34826025 PMCID: PMC9458594 DOI: 10.1007/s11120-021-00883-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/22/2021] [Indexed: 05/16/2023]
Abstract
One of the main mysteries regarding photosynthetic sea slugs is how the slug plastids handle photoinhibition, the constant light-induced damage to Photosystem II of photosynthesis. Recovery from photoinhibition involves proteins encoded by both the nuclear and plastid genomes, and slugs with plastids isolated from the algal nucleus are therefore expected to be incapable of constantly repairing the damage as the plastids inside the slugs grow old. We studied photoinhibition-related properties of the sea slug Elysia timida that ingests its plastids from the green alga Acetabularia acetabulum. Spectral analysis of both the slugs and the algae revealed that there are two ways the slugs use to avoid major photoinhibition of their plastids. Firstly, highly photoinhibitory UV radiation is screened by the slug tissue or mucus before it reaches the plastids. Secondly, the slugs pack the plastids tightly in their thick bodies, and therefore plastids in the outer layers protect the inner ones from photoinhibition. Both properties are expected to greatly improve the longevity of the plastids inside the slugs, as the plastids do not need to repair excessive amounts of damage.
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Affiliation(s)
- Vesa Havurinne
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Riina Aitokari
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Heta Mattila
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Ville Käpylä
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Esa Tyystjärvi
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland.
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7
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Maeda T, Takahashi S, Yoshida T, Shimamura S, Takaki Y, Nagai Y, Toyoda A, Suzuki Y, Arimoto A, Ishii H, Satoh N, Nishiyama T, Hasebe M, Maruyama T, Minagawa J, Obokata J, Shigenobu S. Chloroplast acquisition without the gene transfer in kleptoplastic sea slugs, Plakobranchus ocellatus. eLife 2021; 10:60176. [PMID: 33902812 PMCID: PMC8079154 DOI: 10.7554/elife.60176] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 04/01/2021] [Indexed: 12/14/2022] Open
Abstract
Some sea slugs sequester chloroplasts from algal food in their intestinal cells and photosynthesize for months. This phenomenon, kleptoplasty, poses a question of how the chloroplast retains its activity without the algal nucleus. There have been debates on the horizontal transfer of algal genes to the animal nucleus. To settle the arguments, this study reported the genome of a kleptoplastic sea slug, Plakobranchus ocellatus, and found no evidence of photosynthetic genes encoded on the nucleus. Nevertheless, it was confirmed that light illumination prolongs the life of mollusk under starvation. These data presented a paradigm that a complex adaptive trait, as typified by photosynthesis, can be transferred between eukaryotic kingdoms by a unique organelle transmission without nuclear gene transfer. Our phylogenomic analysis showed that genes for proteolysis and immunity undergo gene expansion and are up-regulated in chloroplast-enriched tissue, suggesting that these molluskan genes are involved in the phenotype acquisition without horizontal gene transfer.
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Affiliation(s)
- Taro Maeda
- National Institute for Basic Biology, Okazaki, Japan
| | - Shunichi Takahashi
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyu, Okinawa, Japan
| | - Takao Yoshida
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Shigeru Shimamura
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Yoshihiro Takaki
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Yukiko Nagai
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | | | | | - Asuka Arimoto
- Marine Biological Laboratory, Hiroshima University, Hiroshima, Japan
| | | | - Nori Satoh
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Tomoaki Nishiyama
- Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Mitsuyasu Hasebe
- National Institute for Basic Biology, Okazaki, Japan.,SOKENDAI, the Graduate University for Advanced Studies, Okazaki, Japan
| | | | - Jun Minagawa
- National Institute for Basic Biology, Okazaki, Japan.,SOKENDAI, the Graduate University for Advanced Studies, Okazaki, Japan
| | - Junichi Obokata
- Kyoto Prefectural University, Kyoto, Japan.,Setsunan Universiy, Hirakata, Japan
| | - Shuji Shigenobu
- National Institute for Basic Biology, Okazaki, Japan.,SOKENDAI, the Graduate University for Advanced Studies, Okazaki, Japan
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8
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Vorobyeva OA, Malakhov VV, Ekimova IA. General and fine structure of Aeolidia papillosa cnidosacs (Gastropoda: Nudibranchia). J Morphol 2021; 282:754-768. [PMID: 33713032 DOI: 10.1002/jmor.21346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/06/2021] [Accepted: 03/08/2021] [Indexed: 11/09/2022]
Abstract
Nudibranch mollusks (Gastropoda: Heterobranchia) are widely known for their ability to incorporate some active biochemical compounds of their prey, or even organelles and symbionts of the prey, which assured biological success of this group. At the same time, the process of nematocysts obtaining and incorporation into specific structures called cnidosacs by cladobranch mollusks remain poorly studied. This highlights a necessity of additional ultrastructural studies of cnidosac and adjacent organs in various aeolid mollusks using modern microscopic methods as they may provide new insight into the cnidosac diversity and fine-scale dynamics of nematocysts sequestration process. The present study is focused on the general and fine structure of the cnidosac area in cladobranch Aeolidia papillosa (Aeolidiidae). Specific goals of our study were to provide a detailed description of histological and ultrafine structure of epidermis, upper parts of the digestive glands and the cnidosac, its innervation and proliferation using standard histological techniques, confocal laser scanning microscopy (CLSM) and transmission electron microscopy. Our results clearly demonstrated that A. papillosa cnidosac is a much more complex structure, than it was thought, especially compared with simple cnidosacs found in flabellinids and facelinids. Using CLSM for functional morphological analysis provides a better resolution in visualization of structural elements within a cnidosac compared with traditional histological techniques. We revealed the presence of two cell types in the cnidophage zone: cnidophages and interstitial cells, which differ in ultrastructure and function. Our results also document the presence of a specific cnidopore zone, lined with differentiated cuboid epithelium bearing long microvilli, which likely provides a unidirectional flow of nematocysts during kleptocnides extrusion. For the first time, occurrence of vacuoles containing protective chitinous spindles in the cnidosac epithelium was shown.
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Affiliation(s)
- Olga A Vorobyeva
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir V Malakhov
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
| | - Irina A Ekimova
- Invertebrate Zoology Department, Lomonosov Moscow State University, Moscow, Russia
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9
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Havurinne V, Tyystjärvi E. Photosynthetic sea slugs induce protective changes to the light reactions of the chloroplasts they steal from algae. eLife 2020; 9:57389. [PMID: 33077025 PMCID: PMC7679141 DOI: 10.7554/elife.57389] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 10/07/2020] [Indexed: 12/13/2022] Open
Abstract
Sacoglossan sea slugs are able to maintain functional chloroplasts inside their own cells, and mechanisms that allow preservation of the chloroplasts are unknown. We found that the slug Elysia timida induces changes to the photosynthetic light reactions of the chloroplasts it steals from the alga Acetabularia acetabulum. Working with a large continuous laboratory culture of both the slugs (>500 individuals) and their prey algae, we show that the plastoquinone pool of slug chloroplasts remains oxidized, which can suppress reactive oxygen species formation. Slug chloroplasts also rapidly build up a strong proton-motive force upon a dark-to-light transition, which helps them to rapidly switch on photoprotective non-photochemical quenching of excitation energy. Finally, our results suggest that chloroplasts inside E. timida rely on oxygen-dependent electron sinks during rapid changes in light intensity. These photoprotective mechanisms are expected to contribute to the long-term functionality of the chloroplasts inside the slugs. Plants, algae and a few other organisms rely on a process known as photosynthesis to fuel themselves, as they can harness cellular structures called chloroplasts to convert light into usable energy. Animals typically lack chloroplasts, making them unable to use photosynthesis to power themselves. The sea slug Elysia timida, however, can steal whole chloroplasts from the cells of the algae it consumes: the stolen structures then become part of the cells in the gut of the slug, allowing the animal to gain energy from sunlight. Once they are in the digestive system of the slug, the chloroplasts survive and keep working for longer than expected. Indeed, these structures are often harmed as a side effect of photosynthesis, but the sea slug does not have the right genes to help repair this damage. In addition, conditions inside animal cells are widely different to the ones found inside algae and plants. It is not clear then how the sea slug extends the lifespan of its chloroplasts by preventing damage caused by sunlight. To investigate this question, Havurinne and Tyystjärvi compared photosynthesis in sea slugs and the algae they eat. A range of methods, including measuring fluorescence from the chloroplasts, was used: this revealed that the slug changes the inside of the stolen chloroplasts, making them more resistant to damage. First, when exposed to light the stolen chloroplasts can quickly switch on a mechanism that dissipates light energy to heat, which is less damaging. Second, a molecule that serves as an intermediate during photosynthesis is kept in a ‘safe’ state which prevents it from creating harmful compounds. And finally, additional safeguard molecules ‘deactivate’ compounds that could otherwise mediate damaging reactions. Overall, these measures may reduce the efficiency of the chloroplasts but allow them to keep working for much longer. Early chloroplasts were probably independent bacteria that were captured and ‘domesticated’ by other cells for their ability to extract energy from the sun. Photosynthesizing sea slugs therefore provide an interesting way to understand some of the challenges of early life. The work by Havurinne and Tyystjärvi may also reveal new ways to harness biological processes such as photosynthesis for energy production in other contexts.
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Affiliation(s)
- Vesa Havurinne
- University of Turku, Department of Biochemistry / Molecular Plant Biology, Turku, Finland
| | - Esa Tyystjärvi
- University of Turku, Department of Biochemistry / Molecular Plant Biology, Turku, Finland
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10
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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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11
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Better off alone? New insights in the symbiotic relationship between the flatworm Symsagittifera roscoffensis and the microalgae Tetraselmis convolutae. Symbiosis 2020. [DOI: 10.1007/s13199-020-00691-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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12
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Donohoo SA, Wade RM, Sherwood AR. Finding the Sweet Spot: Sub-Ambient Light Increases Fitness and Kleptoplast Survival in the Sea Slug Plakobranchus cf. ianthobaptus Gould, 1852. THE BIOLOGICAL BULLETIN 2020; 238:154-166. [PMID: 32597715 DOI: 10.1086/709371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Sacoglossans, or "sap-sucking" sea slugs, are primarily algivorous, with many taxa exhibiting kleptoplasty, the feeding and retaining of photosynthetically active chloroplasts from algae. The Plakobranchus species complex exhibits some of the longest kleptoplast retention and survival times under starvation conditions, but the contributions of these kleptoplasts to their survival and overall fitness have been widely debated. In this study we assessed the effects of starvation and light on the fitness of Plakobranchus cf. ianthobaptus and its kleptoplasts by placing starved individuals in eight daily average light treatments, ranging from near dark (2 µmol photon m-2 s-1) to ambient light (470 µmol photon m-2 s-1). Slug weight was used as a metric of fitness, and kleptoplast photosynthetic activity was determined via maximum quantum yield (Fv/Fm) by pulse-amplitude modulated fluorometry as a proxy for kleptoplast health. Plakobranchus individuals in near-dark and high light treatments (>160 µmol photon m-2 s-1) experienced significantly greater weight loss than those in low light (65 µmol photon m-2 s-1) and moderate light treatments (95-135 µmol photon m-2 s-1). Additionally, individuals in high light treatments experienced a rapid decline in kleptoplast photosynthetic activity, while all other treatments experienced minimal decline. This relationship between kleptoplast degradation and weight loss suggests an important link between fitness and kleptoplasty. Given the significant negative effects of ambient conditions, regular refreshment and replenishment of kleptoplasts or physiological or behavioral adjustments are likely employed for the benefits of kleptoplasty to be maintained.
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Cartaxana P, Morelli L, Jesus B, Calado G, Calado R, Cruz S. The photon menace: kleptoplast protection in the photosynthetic sea slug Elysia timida. ACTA ACUST UNITED AC 2019; 222:jeb.202580. [PMID: 31171599 DOI: 10.1242/jeb.202580] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/02/2019] [Indexed: 11/20/2022]
Abstract
Absorption of excessive light by photosymbiotic organisms leads to the production of reactive oxygen species that can damage both symbiont and host. This is highly relevant in sacoglossan sea slugs that host functional chloroplasts 'stolen' from their algal foods (kleptoplasts), because of limited repair capacities resulting from the absence of algal nuclear genes. Here, we experimentally demonstrate (i) a host-mediated photoprotection mechanism in the photosynthetic sea slug Elysia timida, characterized by the closure of the parapodia under high irradiance and the reduction of kleptoplast light exposure; and (ii) the activation of a reversible xanthophyll cycle in kleptoplasts, which allows excessive energy to be dissipated. The described mechanisms reduce photoinactivation under high irradiance. We conclude that both host-mediated behavioural and plastid-based physiological photoprotective mechanisms can mitigate oxidative stress induced by high light in E. timida These mechanisms may play an important role in the establishment of long-term photosynthetically active kleptoplasts.
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Affiliation(s)
- Paulo Cartaxana
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Luca Morelli
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Bruno Jesus
- Laboratoire Mer Molécules Santé, Faculté des Sciences et des Techniques, Université de Nantes, 44322 Nantes, France
| | - Gonçalo Calado
- Departamento de Ciências da Vida, Universidade Lusófona, 1749-024 Lisboa, Portugal
| | - Ricardo Calado
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Sónia Cruz
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Dionísio G, Faleiro F, Bispo R, Lopes AR, Cruz S, Paula JR, Repolho T, Calado R, Rosa R. Distinct Bleaching Resilience of Photosynthetic Plastid-Bearing Mollusks Under Thermal Stress and High CO 2 Conditions. Front Physiol 2018; 9:1675. [PMID: 30555338 PMCID: PMC6284066 DOI: 10.3389/fphys.2018.01675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/08/2018] [Indexed: 11/29/2022] Open
Abstract
The impact of temperature on photo-symbiotic relationships has been highly studied in the tropical reef-forming corals but overlooked in less charismatic groups such as solar-powered sacoglossan sea slugs. These organisms display one of the most puzzling symbiotic features observed in the animal kingdom, i.e., their mollusk-plastid association, which enables them to retain photosynthetic active chloroplasts (i.e., kleptoplasts) retrieved from their algae feed sources. Here we analyze the impact of thermal stress (+4°C) and high pCO2 conditions (ΔpH = 0.4) in survival, photophysiology (i.e., bleaching, photosynthetic efficiency, and metabolism) and stress defense mechanisms (i.e., heat shock and antioxidant response) of solar-powered sacoglossan sea slugs, from tropical (Elysia crispata) and temperate (E. viridis) environments. High temperature was the main factor affecting the survival of both species, while pH only affected the survival of the temperate model. The photobiology of E. viridis remained stable under the combined scenario, while photoinhibition was observed for E. crispata under high temperature and high pCO2. In fact, bleaching was observed within all tropical specimens exposed to warming (but not in the temperate ones), which constitutes the first report where the incidence of bleaching in tropical animals hosting photosynthetic symbionts, other than corals, occurs. Yet, the expulsion of kleptoplasts by the tropical sea slug, allied with metabolic depression, constituted a physiological response that did not imply signs of vulnerability (i.e., mortality) in the host itself. Although the temperate species revealed greater heat shock and antioxidant enzyme response to environmental stress, we argue that the tropical (stenotherm) sea slug species may display a greater scope for acclimatization than the temperate (eurytherm) sea slug. E. crispata may exhibit increased capacity for phenotypic plasticity by increasing fitness in a much narrower thermal niche (minimizing maintenance costs), which ultimately may allow to face severe environmental conditions more effectively than its temperate generalist counterpart (E. viridis).
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Affiliation(s)
- Gisela Dionísio
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Aveiro, Portugal
- Naturalist Science & Tourism, Horta, Portugal
| | - Filipa Faleiro
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Regina Bispo
- Departamento de Matemática, Centro de Matemática e Aplicações, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa de Caparica, Portugal
| | - Ana Rita Lopes
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Sónia Cruz
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Aveiro, Portugal
| | - José Ricardo Paula
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Tiago Repolho
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
| | - Ricardo Calado
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Aveiro, Portugal
| | - Rui Rosa
- MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia – Faculdade de Ciências da Universidade de Lisboa, Cascais, Portugal
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Christa G, Pütz L, Sickinger C, Melo Clavijo J, Laetz EMJ, Greve C, Serôdio J. Photoprotective Non-photochemical Quenching Does Not Prevent Kleptoplasts From Net Photoinactivation. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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16
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Inorganic carbon and nitrogen assimilation in cellular compartments of a benthic kleptoplastic foraminifer. Sci Rep 2018; 8:10140. [PMID: 29973634 PMCID: PMC6031614 DOI: 10.1038/s41598-018-28455-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/20/2018] [Indexed: 11/08/2022] Open
Abstract
Haynesina germanica, an ubiquitous benthic foraminifer in intertidal mudflats, has the remarkable ability to isolate, sequester, and use chloroplasts from microalgae. The photosynthetic functionality of these kleptoplasts has been demonstrated by measuring photosystem II quantum efficiency and O2 production rates, but the precise role of the kleptoplasts in foraminiferal metabolism is poorly understood. Thus, the mechanism and dynamics of C and N assimilation and translocation from the kleptoplasts to the foraminiferal host requires study. The objective of this study was to investigate, using correlated TEM and NanoSIMS imaging, the assimilation of inorganic C and N (here ammonium, NH4+) in individuals of a kleptoplastic benthic foraminiferal species. H. germanica specimens were incubated for 20 h in artificial seawater enriched with H13CO3- and 15NH4+ during a light/dark cycle. All specimens (n = 12) incorporated 13C into their endoplasm stored primarily in the form of lipid droplets. A control incubation in darkness resulted in no 13C-uptake, strongly suggesting that photosynthesis is the process dominating inorganic C assimilation. Ammonium assimilation was observed both with and without light, with diffuse 15N-enrichment throughout the cytoplasm and distinct 15N-hotspots in fibrillar vesicles, electron-opaque bodies, tubulin paracrystals, bacterial associates, and, rarely and at moderate levels, in kleptoplasts. The latter observation might indicate that the kleptoplasts are involved in N assimilation. However, the higher N assimilation observed in the foraminiferal endoplasm incubated without light suggests that another cytoplasmic pathway is dominant, at least in darkness. This study clearly shows the advantage provided by the kleptoplasts as an additional source of carbon and provides observations of ammonium uptake by the foraminiferal cell.
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Cartaxana P, Morelli L, Quintaneiro C, Calado G, Calado R, Cruz S. Kleptoplast photoacclimation state modulates the photobehaviour of the solar-powered sea slug Elysia viridis. ACTA ACUST UNITED AC 2018; 221:jeb.180463. [PMID: 29712748 DOI: 10.1242/jeb.180463] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
Some sacoglossan sea slugs incorporate intracellular functional algal chloroplasts (kleptoplasty) for periods ranging from a few days to several months. Whether this association modulates the photobehaviour of solar-powered sea slugs is unknown. In this study, the long-term kleptoplast retention species Elysia viridis showed avoidance of dark independently of light acclimation state. In contrast, Placida dendritica, which shows non-functional retention of kleptoplasts, showed no preference over dark, low or high light. High light-acclimated (HLac) E. viridis showed a higher preference for high light than low light-acclimated (LLac) conspecifics. The position of the lateral folds (parapodia) was modulated by irradiance, with increasing light levels leading to a closure of parapodia and protection of kleptoplasts from high light exposure. Furthermore, closure of parapodia occurred at higher irradiance in HLacE. viridis Our results strongly indicate that kleptoplast photoacclimation state modulates the photobehaviour of the solar-powered sea slug E. viridis.
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Affiliation(s)
- Paulo Cartaxana
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Luca Morelli
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal.,Dipartimento di Scienze Agrarie, Alimentari e Agro-ambientali, Università di Pisa, 56124 Pisa, Italy
| | - Carla Quintaneiro
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Gonçalo Calado
- Departamento de Ciências da Vida, Universidade Lusófona, 1749-024 Lisboa, Portugal
| | - Ricardo Calado
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Sónia Cruz
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Melo Clavijo J, Donath A, Serôdio J, Christa G. Polymorphic adaptations in metazoans to establish and maintain photosymbioses. Biol Rev Camb Philos Soc 2018; 93:2006-2020. [PMID: 29808579 DOI: 10.1111/brv.12430] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 12/21/2022]
Abstract
Mutualistic symbioses are common throughout the animal kingdom. Rather unusual is a form of symbiosis, photosymbiosis, where animals are symbiotic with photoautotrophic organisms. Photosymbiosis is found among sponges, cnidarians, flatworms, molluscs, ascidians and even some amphibians. Generally the animal host harbours a phototrophic partner, usually a cyanobacteria or a unicellular alga. An exception to this rule is found in some sea slugs, which only retain the chloroplasts of the algal food source and maintain them photosynthetically active in their own cytosol - a phenomenon called 'functional kleptoplasty'. Research has focused largely on the biodiversity of photosymbiotic species across a range of taxa. However, many questions with regard to the evolution of the ability to establish and maintain a photosymbiosis are still unanswered. To date, attempts to understand genome adaptations which could potentially lead to the evolution of photosymbioses have only been performed in cnidarians. This knowledge gap for other systems is mainly due to a lack of genetic information, both for non-symbiotic and symbiotic species. Considering non-photosymbiotic species is, however, important to understand the factors that make symbiotic species so unique. Herein we provide an overview of the diversity of photosymbioses across the animal kingdom and discuss potential scenarios for the evolution of this association in different lineages. We stress that the evolution of photosymbiosis is probably based on genome adaptations, which (i) lead to recognition of the symbiont to establish the symbiosis, and (ii) are needed to maintain the symbiosis. We hope to stimulate research involving sequencing the genomes of various key taxa to increase the genomic resources needed to understand the most fundamental question: how have animals evolved the ability to establish and maintain a photosymbiosis?
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Affiliation(s)
- Jenny Melo Clavijo
- Center for Molecular Biodiversity Research (zmb), Zoological Research Museum Alexander Koenig, Adenauerallee 160, Bonn, 53113, Germany
| | - Alexander Donath
- Center for Molecular Biodiversity Research (zmb), Zoological Research Museum Alexander Koenig, Adenauerallee 160, Bonn, 53113, Germany
| | - João Serôdio
- Department of Biology and Center for Environmental and Marine Studies, University of Aveiro, Campus Santiago, Aveiro, 3810-192, Portugal
| | - Gregor Christa
- Center for Molecular Biodiversity Research (zmb), Zoological Research Museum Alexander Koenig, Adenauerallee 160, Bonn, 53113, Germany.,Department of Biology and Center for Environmental and Marine Studies, University of Aveiro, Campus Santiago, Aveiro, 3810-192, Portugal
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Laetz EMJ, Wägele H. Chloroplast digestion and the development of functional kleptoplasty in juvenile Elysia timida (Risso, 1818) as compared to short-term and non-chloroplast-retaining sacoglossan slugs. PLoS One 2017; 12:e0182910. [PMID: 29020043 PMCID: PMC5636068 DOI: 10.1371/journal.pone.0182910] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/26/2017] [Indexed: 01/13/2023] Open
Abstract
Sacoglossan sea slugs are the only metazoans known to perform functional kleptoplasty, the sequestration and retention of functional chloroplasts within their digestive gland cells. Remarkably, a few species with this ability can survive starvation periods of 3–12 months likely due to their stolen chloroplasts. There are no reports of kleptoplast transfer from mother slug to either eggs or juveniles, demonstrating that each animal must independently acquire its kleptoplasts and develop the ability to maintain them within its digestive gland. We present here an investigation into the development of functional kleptoplasty in a long-term kleptoplast retaining species, Elysia timida. Laboratory-reared juvenile slugs of different post-metamorphic ages were placed in starvation and compared to 5 known short-term retaining slug species and 5 non-retaining slug species. The subsequent results indicate that functional kleptoplasty is not performed by E. timida until after 15 days post-metamorphosis and that by 25 days, these animals outlive many of the short-term retention species. Digestive activity was also monitored using lysosomal abundance as an indicator, revealing different patterns in starving juveniles versus adults. Starved juveniles were reintroduced to food to determine any differences in digestive activity when starvation ends, resulting in an increase in the number of kleptoplasts, but no overall change in lysosomal activity. By revealing some of the changes that occur during early development in these animals, which begin as non-kleptoplast-retaining and grow into long-term retaining slugs, this investigation provides a basis for future inquiries into the origin and development of this remarkable ability.
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Affiliation(s)
- Elise Marie Jerschabek Laetz
- Center for Molecular Biodiversity Research (ZMB), Zoological Research Museum Alexander Koenig Adenauerallee 160 Bonn, Germany
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1 Bonn, Germany
- * E-mail:
| | - Heike Wägele
- Center for Molecular Biodiversity Research (ZMB), Zoological Research Museum Alexander Koenig Adenauerallee 160 Bonn, Germany
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20
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Rey F, Costa ED, Campos AM, Cartaxana P, Maciel E, Domingues P, Domingues MRM, Calado R, Cruz S. Kleptoplasty does not promote major shifts in the lipidome of macroalgal chloroplasts sequestered by the sacoglossan sea slug Elysia viridis. Sci Rep 2017; 7:11502. [PMID: 28904377 PMCID: PMC5597624 DOI: 10.1038/s41598-017-12008-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/31/2017] [Indexed: 01/19/2023] Open
Abstract
Sacoglossan sea slugs, also known as crawling leaves due to their photosynthetic activity, are highly selective feeders that incorporate chloroplasts from specific macroalgae. These “stolen” plastids - kleptoplasts - are kept functional inside animal cells and likely provide an alternative source of energy to their host. The mechanisms supporting the retention and functionality of kleptoplasts remain unknown. A lipidomic mass spectrometry-based analysis was performed to study kleptoplasty of the sacoglossan sea slug Elysia viridis fed with Codium tomentosum. Total lipid extract of both organisms was fractionated. The fraction rich in glycolipids, exclusive lipids from chloroplasts, and the fraction rich in betaine lipids, characteristic of algae, were analysed using hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-LC-MS). This approach allowed the identification of 81 molecular species, namely galactolipids (8 in both organisms), sulfolipids (17 in C. tomentosum and 13 in E. viridis) and betaine lipids (51 in C. tomentosum and 41 in E. viridis). These lipid classes presented similar lipidomic profiles in C. tomentosum and E. viridis, indicating that the necessary mechanisms to perform photosynthesis are preserved during the process of endosymbiosis. The present study shows that there are no major shifts in the lipidome of C. tomentosum chloroplasts sequestered by E. viridis.
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Affiliation(s)
- Felisa Rey
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Elisabete da Costa
- Centro de Espetrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Ana M Campos
- Centro de Espetrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Paulo Cartaxana
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Elisabete Maciel
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.,Centro de Espetrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Pedro Domingues
- Centro de Espetrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - M Rosário M Domingues
- Centro de Espetrometria de Massa, Departamento de Química & QOPNA, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Ricardo Calado
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Sónia Cruz
- Departamento de Biologia & CESAM & ECOMARE, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
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Rauch C, Jahns P, Tielens AGM, Gould SB, Martin WF. On Being the Right Size as an Animal with Plastids. FRONTIERS IN PLANT SCIENCE 2017; 8:1402. [PMID: 28861094 PMCID: PMC5562673 DOI: 10.3389/fpls.2017.01402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/27/2017] [Indexed: 06/07/2023]
Abstract
Plastids typically reside in plant or algal cells-with one notable exception. There is one group of multicellular animals, sea slugs in the order Sacoglossa, members of which feed on siphonaceous algae. The slugs sequester the ingested plastids in the cytosol of cells in their digestive gland, giving the animals the color of leaves. In a few species of slugs, including members of the genus Elysia, the stolen plastids (kleptoplasts) can remain morphologically intact for weeks and months, surrounded by the animal cytosol, which is separated from the plastid stroma by only the inner and outer plastid membranes. The kleptoplasts of the Sacoglossa are the only case described so far in nature where plastids interface directly with the metazoan cytosol. That makes them interesting in their own right, but it has also led to the idea that it might someday be possible to engineer photosynthetic animals. Is that really possible? And if so, how big would the photosynthetic organs of such animals need to be? Here we provide two sets of calculations: one based on a best case scenario assuming that animals with kleptoplasts can be, on a per cm2 basis, as efficient at CO2 fixation as maize leaves, and one based on 14CO2 fixation rates measured in plastid-bearing sea slugs. We also tabulate an overview of the literature going back to 1970 reporting direct measurements or indirect estimates of the CO2 fixing capabilities of Sacoglossan slugs with plastids.
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Affiliation(s)
- Cessa Rauch
- Molecular Evolution, Heinrich-Heine-UniversityDüsseldorf, Germany
| | - Peter Jahns
- Plant Biochemistry, Heinrich-Heine-UniversityDüsseldorf, Germany
| | - Aloysius G. M. Tielens
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht UniversityUtrecht, Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical CenterRotterdam, Netherlands
| | - Sven B. Gould
- Molecular Evolution, Heinrich-Heine-UniversityDüsseldorf, Germany
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22
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Kleptoplast photosynthesis is nutritionally relevant in the sea slug Elysia viridis. Sci Rep 2017; 7:7714. [PMID: 28798379 PMCID: PMC5552801 DOI: 10.1038/s41598-017-08002-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 07/06/2017] [Indexed: 12/02/2022] Open
Abstract
Several sacoglossan sea slug species feed on macroalgae and incorporate chloroplasts into tubular cells of their digestive diverticula. We investigated the role of the “stolen” chloroplasts (kleptoplasts) in the nutrition of the sea slug Elysia viridis and assessed how their abundance, distribution and photosynthetic activity were affected by light and starvation. Elysia viridis individuals feeding on the macroalga Codium tomentosum were compared with starved specimens kept in dark and low light conditions. A combination of variable Chl a fluorescence and hyperspectral imaging, and HPLC pigment analysis was used to evaluate the spatial and temporal variability of photopigments and of the photosynthetic capacity of kleptoplasts. We show increased loss of weight and body length in dark-starved E. viridis as compared to low light-starved sea slugs. A more pronounced decrease in kleptoplast abundance and lower photosynthetic electron transport rates were observed in dark-starved sea slugs than in low light-starved animals. This study presents strong evidence of the importance of kleptoplast photosynthesis for the nutrition of E. viridis in periods of food scarcity. Deprived of photosynthates, E. viridis could accelerate the breakdown of kleptoplasts in the dark to satisfy its’ energy requirements.
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23
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Bornancin L, Bonnard I, Mills SC, Banaigs B. Chemical mediation as a structuring element in marine gastropod predator-prey interactions. Nat Prod Rep 2017; 34:644-676. [DOI: 10.1039/c6np00097e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Some diterpenoid compounds protect the sacoglossansElysiasp. andCyerce nigricansfrom their carnivorous predator the dorid nudibranch,Gymnodorissp., unlike chemically unprotected gastropods that are consumed by this voracious nudibranch (photo Philippe Bourseiller).
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Affiliation(s)
- L. Bornancin
- CRIOBE
- USR CNRS-EPHE-UPVD 3278
- Université de Perpignan
- 66860 Perpignan
- France
| | - I. Bonnard
- CRIOBE
- USR CNRS-EPHE-UPVD 3278
- Université de Perpignan
- 66860 Perpignan
- France
| | - S. C. Mills
- PSL Research University
- CRIOBE
- USR EPHE-UPVD-CNRS 3278
- 98729 Moorea
- French Polynesia
| | - B. Banaigs
- CRIOBE
- USR CNRS-EPHE-UPVD 3278
- Université de Perpignan
- 66860 Perpignan
- France
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Stamatakis K, Vayenos D, Kotakis C, Gast RJ, Papageorgiou GC. The extraordinary longevity of kleptoplasts derived from the Ross Sea haptophyte Phaeocystis antarctica within dinoflagellate host cells relates to the diminished role of the oxygen-evolving Photosystem II and to supplementary light harvesting by mycosporine-like amino acid/s. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1858:189-195. [PMID: 27940021 DOI: 10.1016/j.bbabio.2016.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 12/05/2016] [Accepted: 12/07/2016] [Indexed: 11/30/2022]
Abstract
The haptophyte Phaeocystis antarctica and the novel Ross Sea dinoflagellate that hosts kleptoplasts derived from P. antarctica (RSD; R.J. Gast et al., 2006, J. Phycol. 42 233-242) were compared for photosynthetic light harvesting and for oxygen evolution activity. Both chloroplasts and kleptoplasts emit chlorophyll a (Chl a) fluorescence peaking at 683nm (F683) at 277K and at 689 (F689) at 77K. Second derivative analysis of the F689 band at 77K revealed two individual contributions centered at 683nm (Fi-683) and at 689 (Fi-689). Using the p-nitrothiophenol (p-NTP) treatment of Kobayashi et al. (Biochim. Biophys. Acta 423 (1976) 80-90) to differentiate between Photosystem (PS) II and I fluorescence emissions, we could identify PS II as the origin of Fi-683 and PS I as the origin of Fi-689. Both emissions could be excited not only by Chl a-selective light (436nm) but also by mycosporine-like amino acids (MAAs)-selective light (345nm). This suggests that a fraction of MAAs must be proximal to Chls a and, therefore, located within the plastids. On the basis of second derivative fluorescence spectra at 77K, of p-NTP resolved fluorescence spectra, as well as of PSII-driven oxygen evolution activities, PS II appears substantially less active (~1/5) in dinoflagellate kleptoplasts than in P. antarctica chloroplasts. We suggest that a diminished role of PS II, a known source of reactive oxygen species, and a diminished dependence on nucleus-encoded light-harvesting proteins, due to supplementary light-harvesting by MAAs, may account for the extraordinary longevity of RSD kleptoplasts.
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, NCSR "Demokritos", Aghia Paraskevi, Attikis, Greece.
| | - Dimitris Vayenos
- Institute of Biosciences and Applications, NCSR "Demokritos", Aghia Paraskevi, Attikis, Greece
| | - Christos Kotakis
- Institute of Biosciences and Applications, NCSR "Demokritos", Aghia Paraskevi, Attikis, Greece; Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary; Kontakeika, Karlovassi Samos, GR-83200, Greece
| | - Rebecca J Gast
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - George C Papageorgiou
- Institute of Biosciences and Applications, NCSR "Demokritos", Aghia Paraskevi, Attikis, Greece
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25
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Abstract
Can egalitarian partnerships exist in nature? A new study demonstrates how protist hosts use and abuse their algal symbionts depending on their needs. While this relationship allows protists to survive in low nutrient conditions, it leaves little room for algal retaliation.
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Affiliation(s)
- E Toby Kiers
- Institute of Ecological Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands.
| | - Stuart A West
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
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26
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Shapiro JA. Nothing in Evolution Makes Sense Except in the Light of Genomics: Read-Write Genome Evolution as an Active Biological Process. BIOLOGY 2016; 5:E27. [PMID: 27338490 PMCID: PMC4929541 DOI: 10.3390/biology5020027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/20/2016] [Accepted: 06/02/2016] [Indexed: 01/15/2023]
Abstract
The 21st century genomics-based analysis of evolutionary variation reveals a number of novel features impossible to predict when Dobzhansky and other evolutionary biologists formulated the neo-Darwinian Modern Synthesis in the middle of the last century. These include three distinct realms of cell evolution; symbiogenetic fusions forming eukaryotic cells with multiple genome compartments; horizontal organelle, virus and DNA transfers; functional organization of proteins as systems of interacting domains subject to rapid evolution by exon shuffling and exonization; distributed genome networks integrated by mobile repetitive regulatory signals; and regulation of multicellular development by non-coding lncRNAs containing repetitive sequence components. Rather than single gene traits, all phenotypes involve coordinated activity by multiple interacting cell molecules. Genomes contain abundant and functional repetitive components in addition to the unique coding sequences envisaged in the early days of molecular biology. Combinatorial coding, plus the biochemical abilities cells possess to rearrange DNA molecules, constitute a powerful toolbox for adaptive genome rewriting. That is, cells possess "Read-Write Genomes" they alter by numerous biochemical processes capable of rapidly restructuring cellular DNA molecules. Rather than viewing genome evolution as a series of accidental modifications, we can now study it as a complex biological process of active self-modification.
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Affiliation(s)
- James A Shapiro
- Department of Biochemistry and Molecular Biology, University of Chicago, GCIS W123B, 979 E. 57th Street, Chicago, IL 60637, USA.
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27
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Stefano GB, Kream RM. Dysregulated mitochondrial and chloroplast bioenergetics from a translational medical perspective (Review). Int J Mol Med 2016; 37:547-55. [PMID: 26821064 PMCID: PMC4771107 DOI: 10.3892/ijmm.2016.2471] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/22/2016] [Indexed: 02/06/2023] Open
Abstract
Mitochondria and chloroplasts represent endosymbiotic models of complex organelle development, driven by intense evolutionary pressure to provide exponentially enhanced ATP-dependent energy production functionally linked to cellular respiration and photosynthesis. Within the realm of translational medicine, it has become compellingly evident that mitochondrial dysfunction, resulting in compromised cellular bioenergetics, represents a key causative factor in the etiology and persistence of major diseases afflicting human populations. As a pathophysiological consequence of enhanced oxygen utilization that is functionally uncoupled from the oxidative phosphorylation of ADP, significant levels of reactive oxygen species (ROS) may be generated within mitochondria and chloroplasts, which may effectively compromise cellular energy production following prolonged stress/inflammatory conditions. Empirically determined homologies in biochemical pathways, and their respective encoding gene sequences between chloroplasts and mitochondria, suggest common origins via entrapped primordial bacterial ancestors. From evolutionary and developmental perspectives, the elucidation of multiple biochemical and molecular relationships responsible for errorless bioenergetics within mitochondrial and plastid complexes will most certainly enhance the depth of translational approaches to ameliorate or even prevent the destructive effects of multiple disease states. The selective choice of discussion points contained within the present review is designed to provide theoretical bases and translational insights into the pathophysiology of human diseases from a perspective of dysregulated mitochondrial bioenergetics with special reference to chloroplast biology.
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28
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Network-Thinking: Graphs to Analyze Microbial Complexity and Evolution. Trends Microbiol 2016; 24:224-237. [PMID: 26774999 PMCID: PMC4766943 DOI: 10.1016/j.tim.2015.12.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 12/02/2015] [Accepted: 12/08/2015] [Indexed: 01/23/2023]
Abstract
The tree model and tree-based methods have played a major, fruitful role in evolutionary studies. However, with the increasing realization of the quantitative and qualitative importance of reticulate evolutionary processes, affecting all levels of biological organization, complementary network-based models and methods are now flourishing, inviting evolutionary biology to experience a network-thinking era. We show how relatively recent comers in this field of study, that is, sequence-similarity networks, genome networks, and gene families–genomes bipartite graphs, already allow for a significantly enhanced usage of molecular datasets in comparative studies. Analyses of these networks provide tools for tackling a multitude of complex phenomena, including the evolution of gene transfer, composite genes and genomes, evolutionary transitions, and holobionts. Introgressive processes shape the microbial world at all levels of organisation. This reticulated evolution is increasingly studied by sequence-similarity networks. They provide an inclusive accurate multilevel framework to study the web of life. Networks enhance analyses of microbial genes, genomes, communities, and of symbiosis.
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29
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Marine and terrestrial herbivores display convergent chemical ecology despite 400 million years of independent evolution. Proc Natl Acad Sci U S A 2015; 112:12110-5. [PMID: 26324909 DOI: 10.1073/pnas.1508133112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chemical cues regulate key ecological interactions in marine and terrestrial ecosystems. They are particularly important in terrestrial plant-herbivore interactions, where they mediate both herbivore foraging and plant defense. Although well described for terrestrial interactions, the identity and ecological importance of herbivore foraging cues in marine ecosystems remain unknown. Here we show that the specialist gastropod Elysia tuca hunts its seaweed prey, Halimeda incrassata, by tracking 4-hydroxybenzoic acid to find vegetative prey and the defensive metabolite halimedatetraacetate to find reproductive prey. Foraging cues were predicted to be polar compounds but instead were nonpolar secondary metabolites similar to those used by specialist terrestrial insects. Tracking halimedatetraacetate enables Elysia to increase in abundance by 12- to 18-fold on reproductive Halimeda, despite reproduction in Halimeda being rare and lasting for only ∼36 h. Elysia swarm to reproductive Halimeda where they consume the alga's gametes, which are resource rich but are chemically defended from most consumers. Elysia sequester functional chloroplasts and halimedatetraacetate from Halimeda to become photosynthetic and chemically defended. Feeding by Elysia suppresses the growth of vegetative Halimeda by ∼50%. Halimeda responds by dropping branches occupied by Elysia, apparently to prevent fungal infection associated with Elysia feeding. Elysia is remarkably similar to some terrestrial insects, not only in its hunting strategy, but also its feeding method, defense tactics, and effects on prey behavior and performance. Such striking parallels indicate that specialist herbivores in marine and terrestrial systems can evolve convergent ecological strategies despite 400 million years of independent evolution in vastly different habitats.
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30
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Rauch C, Vries JD, Rommel S, Rose LE, Woehle C, Christa G, Laetz EM, Wägele H, Tielens AGM, Nickelsen J, Schumann T, Jahns P, Gould SB. Why It Is Time to Look Beyond Algal Genes in Photosynthetic Slugs. Genome Biol Evol 2015; 7:2602-7. [PMID: 26319575 PMCID: PMC4607529 DOI: 10.1093/gbe/evv173] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Eukaryotic organelles depend on nuclear genes to perpetuate their biochemical integrity. This is true for mitochondria in all eukaryotes and plastids in plants and algae. Then how do kleptoplasts, plastids that are sequestered by some sacoglossan sea slugs, survive in the animals’ digestive gland cells in the absence of the algal nucleus encoding the vast majority of organellar proteins? For almost two decades, lateral gene transfer (LGT) from algae to slugs appeared to offer a solution, but RNA-seq analysis, later supported by genome sequencing of slug DNA, failed to find any evidence for such LGT events. Yet, isolated reports continue to be published and are readily discussed by the popular press and social media, making the data on LGT and its support for kleptoplast longevity appear controversial. However, when we take a sober look at the methods used, we realize that caution is warranted in how the results are interpreted. There is no evidence that the evolution of kleptoplasty in sea slugs involves LGT events. Based on what we know about photosystem maintenance in embryophyte plastids, we assume kleptoplasts depend on nuclear genes. However, studies have shown that some isolated algal plastids are, by nature, more robust than those of land plants. The evolution of kleptoplasty in green sea slugs involves many promising and unexplored phenomena, but there is no evidence that any of these require the expression of slug genes of algal origin.
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Affiliation(s)
- Cessa Rauch
- Molecular Evolution, Heinrich-Heine-University Düsseldorf, Germany
| | - Jan de Vries
- Molecular Evolution, Heinrich-Heine-University Düsseldorf, Germany
| | - Sophie Rommel
- Population Genetics, Heinrich-Heine-University Düsseldorf, Germany
| | - Laura E Rose
- Population Genetics, Heinrich-Heine-University Düsseldorf, Germany
| | - Christian Woehle
- Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität ZMB, Am Botanischen Garten, Kiel, Germany
| | - Gregor Christa
- Molecular Evolution, Heinrich-Heine-University Düsseldorf, Germany
| | - Elise M Laetz
- Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany
| | - Aloysius G M Tielens
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Tobias Schumann
- Plant Biochemistry and Stress Physiology, Heinrich-Heine-University Düsseldorf, Germany
| | - Peter Jahns
- Plant Biochemistry and Stress Physiology, Heinrich-Heine-University Düsseldorf, Germany
| | - Sven B Gould
- Molecular Evolution, Heinrich-Heine-University Düsseldorf, Germany
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31
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Stefano GB, Snyder C, Kream RM. Mitochondria, Chloroplasts in Animal and Plant Cells: Significance of Conformational Matching. Med Sci Monit 2015; 21:2073-8. [PMID: 26184462 PMCID: PMC4517925 DOI: 10.12659/msm.894758] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Many commonalities between chloroplasts and mitochondria exist, thereby suggesting a common origin via a bacterial ancestor capable of enhanced ATP-dependent energy production functionally linked to cellular respiration and photosynthesis. Accordingly, the molecular evolution/retention of the catalytic Qo quinol oxidation site of cytochrome b complexes as the tetrapeptide PEWY sequence functionally underlies the common retention of a chemiosmotic proton gradient mechanism for ATP synthesis in cellular respiration and photosynthesis. Furthermore, the dual regulatory targeting of mitochondrial and chloroplast gene expression by mitochondrial transcription termination factor (MTERF) proteins to promote optimal energy production and oxygen consumption further advances these evolutionary contentions. As a functional consequence of enhanced oxygen utilization and production, significant levels of reactive oxygen species (ROS) may be generated within mitochondria and chloroplasts, which may effectively compromise cellular energy production following prolonged stress/inflammationary conditions. Interestingly, both types of organelles have been identified in selected animal cells, most notably specialized digestive cells lining the gut of several species of Sacoglossan sea slugs. Termed kleptoplasty or kleptoplastic endosymbiosis, functional chloroplasts from algal food sources are internalized and stored within digestive cells to provide the host with dual energy sources derived from mitochondrial and photosynthetic processes. Recently, the observation of internalized algae within embryonic tissues of the spotted salamander strongly suggest that developmental processes within a vertebrate organism may require photosynthetic endosymbiosis as an internal regulator. The dual presence of mitochondria and functional chloroplasts within specialized animal cells indicates a high degree of biochemical identity, stereoselectivity, and conformational matching that are the likely keys to their functional presence and essential endosymbiotic activities for over 2.5 billion years.
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32
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Snyder C, Stefano GB. Mitochondria and chloroplasts shared in animal and plant tissues: significance of communication. Med Sci Monit 2015; 21:1507-11. [PMID: 26005853 PMCID: PMC4455318 DOI: 10.12659/msm.894481] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria have long been recognized as the main source of energy production for the eukaryotic cell. Recent studies have found that the mitochondria have a variety of dynamic functions aside from the production of energy. It communicates bidirectionally with other organelles in order to modulate its energy balance efficiently, as well as maintain homeostasis, ultimately prolonging its own and the cell’s longevity. The mitochondria achieves this level of regulation via specific and common bidirectional chemical messengers, especially involving the endoplasmic/sarcoplasmic reticulum (ER/SR), deoxyribonucleoside triphosphates (dNTP’s), ATP and the generation of reactive oxygen species (ROS). Its communication network is also involved in stress associated events. In this regard, the activation of the Bax family proteins and the release of cytochrome c occurs during cellular stress. The communication can also promote apoptosis of the cell. When mitochondrial abnormalities cannot be dealt with, there is an increased chance that major illnesses like type 2 diabetes, Alzheimer’s disease, and cancer may occur. Importantly, functioning chloroplasts can be found in animals, suggesting conserved chemical messengers during its evolutionary path. The dynamic capacity of mitochondria is also noted by their ability to function anaerobically. Indeed, this latter phenomenon may represent a return to an earlier developmental stage of mitochondria, suggesting certain disorders result from its untimely appearance.
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33
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Nissen M, Shcherbakov D, Heyer A, Brümmer F, Schill RO. Behaviour of the plathelminth Symsagittifera roscoffensis under different light conditions and the consequences for the symbiotic algae Tetraselmis convolutae. ACTA ACUST UNITED AC 2015; 218:1693-8. [PMID: 25852067 DOI: 10.1242/jeb.110429] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 03/31/2015] [Indexed: 02/03/2023]
Abstract
Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmis convolutae. Host and symbiont are a model system for the study of endosymbiosis, which has so far mainly focused on their biochemical interactions. Symsagittifera roscoffensis is well known for its positive phototaxis that is hypothesized to optimize the symbiont's light perception for photosynthesis. In this study, we conducted a detailed analysis of phototaxis using light sources of different wavelength and brightness by videotracking. Furthermore, we compared the behavioural data with the electron transfer rate of the photosystem from cultured symbiotic cells. The symbiotic algae is adapted to low light conditions, showing a positive electron transfer rate at a photosynthetically active radiation of 0.112 µmol photons m(-2) s(-1), and S. roscoffensis showed a positive phototactic behaviour for light intensities up to 459.17 µmol photons m(-2) s(-1), which is not optimal regarding the needs of the symbiotic cells and may even harm host and symbiont. Red light cannot be detected by the animals and therefore their eyes seem not to be suitable for measuring the exact photosynthetically active radiation to the benefit of the photosymbionts.
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Affiliation(s)
- Matthias Nissen
- Department of Biophysics, Biological Institute, University of Rostock, Gertrudenstr. 11 A, Rostock 18057, Germany Department of Zoology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, Stuttgart 70569, Germany
| | - Denis Shcherbakov
- Institute of Zoology, University of Hohenheim, Garbenstr. 30, Stuttgart 70593, Germany
| | - Arnd Heyer
- Department of Plant Biotechnology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, Stuttgart 70569, Germany
| | - Franz Brümmer
- Department of Zoology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, Stuttgart 70569, Germany
| | - Ralph O Schill
- Department of Zoology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, Stuttgart 70569, Germany
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34
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Cruz S, Cartaxana P, Newcomer R, Dionísio G, Calado R, Serôdio J, Pelletreau KN, Rumpho ME. Photoprotection in sequestered plastids of sea slugs and respective algal sources. Sci Rep 2015; 5:7904. [PMID: 25601025 PMCID: PMC4298725 DOI: 10.1038/srep07904] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/18/2014] [Indexed: 01/07/2023] Open
Abstract
Some sea slugs are capable of retaining functional sequestered chloroplasts (kleptoplasts) for variable periods of time. The mechanisms supporting the maintenance of these organelles in animal hosts are still largely unknown. Non-photochemical quenching (NPQ) and the occurrence of a xanthophyll cycle were investigated in the sea slugs Elysia viridis and E. chlorotica using chlorophyll fluorescence measurements and pigment analysis. The photoprotective capacity of kleptoplasts was compared to that observed in their respective algal source, Codium tomentosum and Vaucheria litorea. A functional xanthophyll cycle and a rapidly reversible NPQ component were found in V. litorea and E. chlorotica but not in C. tomentosum and E. viridis. To our knowledge, this is the first report of the absence of a functional xanthophyll cycle in a green macroalgae. The absence of a functional xanthophyll cycle in C. tomentosum could contribute to the premature loss of photosynthetic activity and relatively short-term retention of kleptoplasts in E. viridis. On the contrary, E. chlorotica displays one of the longest functional examples of kleptoplasty known so far. We speculate that different efficiencies of photoprotection and repair mechanisms of algal food sources play a role in the longevity of photosynthetic activity in kleptoplasts retained by sea slugs.
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Affiliation(s)
- Sónia Cruz
- Departamento de Biologia &CESAM - Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - Paulo Cartaxana
- MARE - Centro de Ciências do Mar e do Ambiente, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Rebecca Newcomer
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Gisela Dionísio
- 1] Departamento de Biologia &CESAM - Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal [2] MARE - Centro de Ciências do Mar e do Ambiente, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Ricardo Calado
- Departamento de Biologia &CESAM - Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - João Serôdio
- Departamento de Biologia &CESAM - Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - Karen N Pelletreau
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Mary E Rumpho
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
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35
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Christa G, Händeler K, Kück P, Vleugels M, Franken J, Karmeinski D, Wägele H. Phylogenetic evidence for multiple independent origins of functional kleptoplasty in Sacoglossa (Heterobranchia, Gastropoda). ORG DIVERS EVOL 2014. [DOI: 10.1007/s13127-014-0189-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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36
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Spetea C, Rintamäki E, Schoefs B. Changing the light environment: chloroplast signalling and response mechanisms. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130220. [PMID: 24591707 DOI: 10.1098/rstb.2013.0220] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Light is an essential environmental factor required for photosynthesis, but it also mediates signals to control plant development and growth and induces stress tolerance. The photosynthetic organelle (chloroplast) is a key component in the signalling and response network in plants. This theme issue of Philosophical Transactions of the Royal Society of London B: Biology provides updates, highlights and summaries of the most recent findings on chloroplast-initiated signalling cascades and responses to environmental changes, including light and biotic stress. Besides plant molecular cell biology and physiology, the theme issue includes aspects from the cross-disciplinary fields of environmental adaptation, ecology and agronomy.
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Affiliation(s)
- Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, , PO Box 461, Gothenburg 40530, Sweden
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