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Krings W, Neumann C, Gorb SN, Koehnsen A, Wägele H. Elemental composition and material properties of radular teeth in the heterobranch snail Gastropteron rubrum (Mollusca, Gastropoda, Cephalaspidea) foraging on hard organisms. Ecol Evol 2023; 13:e10332. [PMID: 37589038 PMCID: PMC10425275 DOI: 10.1002/ece3.10332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/19/2023] [Accepted: 07/05/2023] [Indexed: 08/18/2023] Open
Abstract
The molluscan feeding structure is the radula, a chitinous membrane with teeth, which are highly adapted to the food and the substrate to which the food is attached. In Polyplacophora and Patellogastropoda, the handling of hard ingesta can be facilitated by high content of chemical compounds containing Fe or Si in the tooth cusps. Other taxa, however, possess teeth that are less mineralized, even though animals have to avoid structural failure or high wear during feeding as well. Here, we investigated the gastropod Gastropteron rubrum, feeding on hard Foraminifera, diatoms and Porifera. Tooth morphologies and wear were documented by scanning electron microscopy and their mechanical properties were tested by nanoindentation. We determined that gradients of hard- and stiffness run along each tooth, decreasing from cusp to basis. We also found that inner lateral teeth were harder and stiffer than the outer ones. These findings allowed us to propose hypotheses about the radula-ingesta interaction. In search for the origins of the gradients, teeth were visualized using confocal laser scanning microscopy, to determine the degree of tanning, and analyzed with energy-dispersive X-ray spectroscopy, to test the elemental composition. We found that the mechanical gradients did not have their origins in the elemental content, as the teeth did not contain high proportions of metals or other minerals. This indicates that their origin might be the degree of tanning. However, in the tooth surfaces that interact with the ingesta high Si and Ca contents were determined, which is likely an adaptation to reduce wear.
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Affiliation(s)
- Wencke Krings
- Department of Electron Microscopy, Institute of Cell and Systems Biology of AnimalsUniversität HamburgHamburgGermany
- Department of Cariology, Endodontology and PeriodontologyUniversität LeipzigLeipzigGermany
- Department of Mammalogy and PalaeoanthropologyLeibniz Institute for the Analysis of Biodiversity ChangeHamburgGermany
- Department of Functional Morphology and Biomechanics, Zoological InstituteChristian‐Albrechts‐Universität zu KielKielGermany
| | - Charlotte Neumann
- Department of Cariology, Endodontology and PeriodontologyUniversität LeipzigLeipzigGermany
- Department of Mammalogy and PalaeoanthropologyLeibniz Institute for the Analysis of Biodiversity ChangeHamburgGermany
| | - Stanislav N. Gorb
- Department of Functional Morphology and Biomechanics, Zoological InstituteChristian‐Albrechts‐Universität zu KielKielGermany
| | - Alexander Koehnsen
- Department of Electron Microscopy, Institute of Cell and Systems Biology of AnimalsUniversität HamburgHamburgGermany
- Department of Cariology, Endodontology and PeriodontologyUniversität LeipzigLeipzigGermany
| | - Heike Wägele
- Department of Phylogenetics and Evolutionary BiologyLeibniz Institute for the Analysis of Biodiversity ChangeBonnGermany
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Krings W, Wägele H, Neumann C, Gorb SN. Coping with abrasive food: diverging composition of radular teeth in two Porifera-consuming nudibranch species (Mollusca, Gastropoda). J R Soc Interface 2023; 20:20220927. [PMID: 37221862 DOI: 10.1098/rsif.2022.0927] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
Molluscs forage with their radula, a chitinous membrane with teeth. Adaptations to hard or abrasive ingesta were well studied in Polyplacophora and Patellogastropoda, but for other taxa there are large gaps in knowledge. Here, we investigated the nudibranch gastropods Felimare picta and Doris pseudoargus, both of which feed on Porifera. Tooth morphologies were documented by scanning electron microscopy, and mechanical properties were tested by nanoindentation. We found that these parameters are rather similar in both species, indicating that teeth are similar in their function. To study the composition, teeth were visualized using confocal laser scanning microscopy (CLSM), to determine the degree of tanning, and analysed with energy-dispersive X-ray spectroscopy, to test the elemental composition. The emitted autofluorescence signal and the inorganic content differed between the species. This was especially prominent when studying the inner and outer tooth surfaces (leading and trailing edges). In F. picta, we detected high proportions of Si, whereas teeth of D. pseudoargus contained high amounts of Ca, which influenced the autofluorescence signal in CLSM. Employing nanoindentation, we determined high Young's modulus and hardness values for the leading edges of teeth, which relate to the Si and Ca content. This highlights that teeth with a similar morphology and mechanical properties can be mechanically enhanced via different chemical pathways in Nudibranchia.
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Affiliation(s)
- Wencke Krings
- Department of Cariology, Endodontology and Periodontology, Universität Leipzig, Liebigstraße 12, 04103 Leipzig, Germany
- Department of Behavioral Biology, Institute of Cell and Systems Biology of Animals, Universität Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
- Department of Mammalogy and Palaeoanthropology, Leibniz Institute for the Analysis of Biodiversity Change, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Heike Wägele
- Department of Phylogenetics and Evolutionary Biology, Leibniz Institute for the Analysis of Biodiversity Change, Adenauerallee 160, 53113 Bonn, Germany
| | - Charlotte Neumann
- Department of Behavioral Biology, Institute of Cell and Systems Biology of Animals, Universität Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
- Department of Mammalogy and Palaeoanthropology, Leibniz Institute for the Analysis of Biodiversity Change, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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Wägele H, Knezevic K, Moustafa AY. Defensive acid-secreting glands in Cypraeoidea (Caenogastropoda, Mollusca). Molluscan Research 2022. [DOI: 10.1080/13235818.2022.2124581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Heike Wägele
- Leibniz Institute for the Analysis of Biodiversity Change, Museum Alexander Koenig Bonn, Bonn, Germany
| | - Kristina Knezevic
- Leibniz Institute for the Analysis of Biodiversity Change, Museum Alexander Koenig Bonn, Bonn, Germany
| | - Alaa Y. Moustafa
- Zoology Department, Faculty of Science, Sohag University, Sohag, Egypt
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Karmeinski D, Meusemann K, Goodheart JA, Schroedl M, Martynov A, Korshunova T, Wägele H, Donath A. Transcriptomics provides a robust framework for the relationships of the major clades of cladobranch sea slugs (Mollusca, Gastropoda, Heterobranchia), but fails to resolve the position of the enigmatic genus Embletonia. BMC Ecol Evol 2021; 21:226. [PMID: 34963462 PMCID: PMC8895541 DOI: 10.1186/s12862-021-01944-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/23/2021] [Indexed: 11/24/2022] Open
Abstract
Background The soft-bodied cladobranch sea slugs represent roughly half of the biodiversity of marine nudibranch molluscs on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as targets for drug discovery), the evolutionary history of cladobranch sea slugs is not yet fully understood. Results To enlarge the current knowledge on the phylogenetic relationships, we generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa (Berthella plumula and Polycera quadrilineata). We complemented our taxon sampling with previously published transcriptome data, resulting in a final data set covering 56 species from all but one accepted cladobranch superfamilies. We assembled all transcriptomes using six different assemblers, selecting those assemblies that provided the largest amount of potentially phylogenetically informative sites. Quality-driven compilation of data sets resulted in four different supermatrices: two with full coverage of genes per species (446 and 335 single-copy protein-coding genes, respectively) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximal statistical support for all major splits and phylogenetic relationships at the family level. Besides the questionable position of Noumeaella rubrofasciata, rendering the Facelinidae as polyphyletic, the only notable discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal. Conclusions Our data matrices and the inferred trees can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The placement of E. pulchra, however, proves challenging, even with large data sets and various optimization strategies. Moreover, quartet mapping results show that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01944-0.
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Affiliation(s)
- Dario Karmeinski
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany
| | - Karen Meusemann
- Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany.,Australian National Insect Collection, National Research Collections Australia, Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Facilities and Collections, Clunies Ross Street, Acton, Canberra, ACT, 2601, Australia
| | - Jessica A Goodheart
- Scripps Institution of Oceanography, University of California, La Jolla, San Diego, CA, 92037, USA
| | - Michael Schroedl
- SNSB-Bavarian State Collection of Zoology, Münchhausenstr. 21, 81247, Munich, Germany.,GeoBioCenter LMU und Biozentrum, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Alexander Martynov
- Zoological Museum of the Moscow State University, Bolshaya Nikitskaya Str. 6, 125009, Moscow, Russia
| | - Tatiana Korshunova
- Koltzov Institute of Developmental Biology, Vavilova Str. 26, 119334, Moscow, Russia
| | - Heike Wägele
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany
| | - Alexander Donath
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change/ZFMK, Museum Koenig, Adenauerallee 160, 53113, Bonn, Germany.
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Bogdanov A, Papu A, Kehraus S, Cruesemann M, Wägele H, König GM. Metabolome of the Phyllidiella pustulosa Species Complex (Nudibranchia, Heterobranchia, Gastropoda) Reveals Rare Dichloroimidic Sesquiterpene Derivatives from a Phylogenetically Distinct and Undescribed Clade. J Nat Prod 2020; 83:2785-2796. [PMID: 32910650 DOI: 10.1021/acs.jnatprod.0c00783] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phyllidiid nudibranchs are brightly colored gastropod mollusks, frequently encountered in coral reefs of the tropical Indo-Pacific. The lack of a protective shell is suggested to be compensated by toxic secondary metabolites that are sequestered from specific prey sponges. Our ongoing reconstruction of phyllidiid phylogeny using molecular data of more than 700 specimens, based on published data and newly collected specimens in various seasons and localities around North Sulawesi (Indonesia), demonstrates that Phyllidiella pustulosa is a species complex with at least seven well-supported clades. A metabolomic analysis of 52 specimens from all seven clades of P. pustulosa was performed. Secondary metabolite profiles were found to correlate with the phylogenetic study and not the prevailing food sponges as expected. GNPS molecular networking revealed a unique chemotype in clade 6. Detailed chemical analysis of a specimen from this chemically and genetically distinct P. pustulosa clade led to the identification of seven new sesquiterpenoids with a rare dichloroimidic moiety (1 and 4) and derivatives thereof (2, 3, 5-7). Our findings suggest that P. pustulosa clades should be raised to the species level.
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Affiliation(s)
- Alexander Bogdanov
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States
| | - Adelfia Papu
- Center of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany
- Faculty of Mathematics and Natural Sciences, Sam Ratulangi University, Manado 95115, Indonesia
| | - Stefan Kehraus
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Max Cruesemann
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Heike Wägele
- Center of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany
| | - Gabriele M König
- Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
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6
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Hertzer C, Kehraus S, Böhringer N, Kaligis F, Bara R, Erpenbeck D, Wörheide G, Schäberle TF, Wägele H, König GM. Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida). Beilstein J Org Chem 2020; 16:1596-1605. [PMID: 32704326 PMCID: PMC7356558 DOI: 10.3762/bjoc.16.132] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/23/2020] [Indexed: 01/21/2023] Open
Abstract
Investigations on the biochemical relationship between Doriprismatica stellata (Chromodorididae, Doridoidea) nudibranchs, their egg ribbons, and the associated dietary sponge Spongia cf. agaricina (Demospongiae, Porifera) led to the isolation of the structurally new scalarane-type sesterterpene 12-deacetoxy-4-demethyl-11,24-diacetoxy-3,4-methylenedeoxoscalarin, with an unprecedented position of the cyclopropane ring annelated to the ring A. Unlike other scalaranes, which are most often functionalized at C-12 of ring C, it bears two acetoxy groups at C-11 and C-24 instead. The compound was present in all three samples, supporting the dietary relationship between chromodorid nudibranchs of the genus Doriprismatica and scalarane-containing dictyoceratid sponges of the Spongiidae family. The results also indicate that D. stellata passes the scalarane metabolite on to its egg ribbons, most likely for protective purposes. The scalarane showed antibacterial activity against the Gram-positive bacteria Arthrobacter crystallopoietes (DSM 20117) and Bacillus megaterium (DSM 32).
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Affiliation(s)
- Cora Hertzer
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Stefan Kehraus
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Nils Böhringer
- Institute for Insect Biotechnology, Justus-Liebig-University, Heinrich-Buff-Ring 26–32, 35392 Gießen, Germany
- Department for Bioresources of the Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, 35392 Gießen, Germany
| | - Fontje Kaligis
- Faculty of Fisheries and Marine Science, Sam Ratulangi University, Jl. Kampus UNSRAT Bahu, 95115 Manado, Sulawesi Utara, Indonesia
| | - Robert Bara
- Faculty of Fisheries and Marine Science, Sam Ratulangi University, Jl. Kampus UNSRAT Bahu, 95115 Manado, Sulawesi Utara, Indonesia
| | - Dirk Erpenbeck
- Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany
- SNSB – Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany
| | - Till F Schäberle
- Institute for Insect Biotechnology, Justus-Liebig-University, Heinrich-Buff-Ring 26–32, 35392 Gießen, Germany
- Department for Bioresources of the Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, 35392 Gießen, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
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Maniei F, Espeland M, Movahedi M, Wägele H. Description of a new Peronia species (Gastropoda: Eupulmonata: Onchidiidae) from Iran, Persian Gulf. Zootaxa 2020; 4758:zootaxa.4758.3.5. [PMID: 32230131 DOI: 10.11646/zootaxa.4758.3.5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Indexed: 11/04/2022]
Abstract
Peronia J. Fleming, 1822 is an eupulmonate slug genus with a wide distribution in the Indo-Pacific Ocean. Currently, nine species are considered as valid. However, molecular data indicate cryptic speciation and more species involved. Here, we present results on a new species found in the Persian Gulf, a subtropical region with harsh conditions such as elevated salinity and high temperature compared to the Indian Ocean. Peronia persiae sp. nov. is described based on molecular, histological, anatomical, micro-computer tomography and scanning electron microscopy data. ABGD, GMYC and bPTP analyses based on 16S rDNA and cytochrome oxidase I (COI) sequences of Peronia confirm the delimitation of the new species. Moreover, our 14 specimens were carefully compared with available information of other described Peronia species. Peronia persiae sp. nov. is distinct in a combination of characters, including differences in the genital (ampulla, prostate, penial hooks, penial needle) and digestive systems (lack of pharyngeal wall teeth, tooth shape in radula, intestine of type II).
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Affiliation(s)
- Fatemeh Maniei
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany..
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8
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Schillo D, Wipfler B, Undap N, Papu A, Böhringer N, Eisenbarth JH, Kaligis F, Bara R, Schäberle TF, König GM, Wägele H. Description of a new Moridilla species from North Sulawesi, Indonesia (Mollusca: Nudibranchia: Aeolidioidea)-based on MicroCT, histological and molecular analyses. Zootaxa 2019; 4652:zootaxa.4652.2.3. [PMID: 31716869 DOI: 10.11646/zootaxa.4652.2.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Indexed: 11/04/2022]
Abstract
We describe a new species, Moridilla jobeli sp. nov., belonging to the marine heterobranch group Aeolidioidea. Up to now, it is only recorded from Bunaken National Park, North Sulawesi, Indonesia. A combination of histological, computer tomographic and scanning electron microscopic methods was applied in order to describe and illustrate the anatomy of Moridilla jobeli sp. nov. in detail. Furthermore, we conducted molecular analyses which include available partial COI and 16S rRNA sequences, as well as the nuclear gene Histone 3 (H3) of Facelinidae and Aeolidiidae. NeighborNet analyses, species delimitation tests and phylogenetic reconstruction methods show the distinctiveness of the new species from the type species Moridilla brockii Bergh, 1888 and the two recently described species Moridilla fifo Carmona Wilson, 2018 and Moridilla hermanita Carmona Wilson, 2018, as well as the monophyly of the genus. A phylogenetic analysis of the Facelinidae and Aeolidiidae does not result in a resolved tree, therefore relationship of former assumed closely related genera, Noumeaella Risbec, 1937 and Palisa Edmunds, 1964, cannot be discussed in detail.
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Affiliation(s)
- Dorothee Schillo
- Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany. Department of Biological Science, National University of Singapore, Singapore..
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Goodheart JA, Bleidißel S, Schillo D, Strong EE, Ayres DL, Preisfeld A, Collins AG, Cummings MP, Wägele H. Comparative morphology and evolution of the cnidosac in Cladobranchia (Gastropoda: Heterobranchia: Nudibranchia). Front Zool 2018; 15:43. [PMID: 30473719 PMCID: PMC6234619 DOI: 10.1186/s12983-018-0289-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/30/2018] [Indexed: 11/10/2022] Open
Abstract
Background A number of shelled and shell-less gastropods are known to use multiple defensive mechanisms, including internally generated or externally obtained biochemically active compounds and structures. Within Nudipleura, nudibranchs within Cladobranchia possess such a special defense: the ability to sequester cnidarian nematocysts - small capsules that can inject venom into the tissues of other organisms. This ability is distributed across roughly 600 species within Cladobranchia, and many questions still remain in regard to the comparative morphology and evolution of the cnidosac - the structure that houses sequestered nematocysts (called kleptocnides). In this paper, we describe cnidosac morphology across the main groups of Cladobranchia in which it occurs, and place variation in its structure in a phylogenetic context to better understand the evolution of nematocyst sequestration. Results Overall, we find that the length, size and structure of the entrance to the cnidosac varies more than expected based on previous work, as does the structure of the exit, the musculature surrounding the cnidosac, and the position and orientation of the kleptocnides. The sequestration of nematocysts has originated at least twice within Cladobranchia based on the phylogeny presented here using 94 taxa and 409 genes. Conclusions The cnidosac is not homologous to cnidosac-like structures found in Hancockiidae. Additionally, the presence of a sac at the distal end of the digestive gland may have originated prior to the sequestration of nematocysts. This study provides a more complete picture of variation in, and evolution of, morphological characters associated with nematocyst sequestration in Cladobranchia.
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Affiliation(s)
- Jessica A Goodheart
- 1Laboratory of Molecular Evolution, Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742 USA.,2NMFS, National Systematics Laboratory, National Museum of Natural History, Smithsonian Institution, MRC-153, PO Box 37012, Washington, DC 20013 USA.,3Department of Invertebrate Zoology, Smithsonian Institution, National Museum of Natural History, MRC 163, P.O. Box 37012, Washington, DC 20013-7012 USA.,4Present address: Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106 USA
| | - Sabrina Bleidißel
- 5Zoology and Didactics of Biology, University of Wuppertal, 42097 Wuppertal, Germany
| | - Dorothee Schillo
- 6Zoologisches Forschungsmuseum Alexander Koenig, 53113 Bonn, Germany
| | - Ellen E Strong
- 3Department of Invertebrate Zoology, Smithsonian Institution, National Museum of Natural History, MRC 163, P.O. Box 37012, Washington, DC 20013-7012 USA
| | - Daniel L Ayres
- 1Laboratory of Molecular Evolution, Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742 USA
| | - Angelika Preisfeld
- 5Zoology and Didactics of Biology, University of Wuppertal, 42097 Wuppertal, Germany
| | - Allen G Collins
- 2NMFS, National Systematics Laboratory, National Museum of Natural History, Smithsonian Institution, MRC-153, PO Box 37012, Washington, DC 20013 USA
| | - Michael P Cummings
- 1Laboratory of Molecular Evolution, Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742 USA
| | - Heike Wägele
- 6Zoologisches Forschungsmuseum Alexander Koenig, 53113 Bonn, Germany
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10
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Laetz EMJ, Wägele H. How does temperature affect functional kleptoplasty? Comparing populations of the solar-powered sister-species Elysia timida Risso, 1818 and Elysia cornigera Nuttall, 1989 (Gastropoda: Sacoglossa). Front Zool 2018; 15:17. [PMID: 29760759 PMCID: PMC5937827 DOI: 10.1186/s12983-018-0264-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 04/06/2018] [Indexed: 01/03/2023] Open
Abstract
Background Despite widespread interest in solar-powered sea slugs (Sacoglossa: Gastropoda), relatively little is know about how they actually perform functional kleptoplasty. Sister-taxa Elysia timida and E. cornigera provide an ideal model system for investigating this phenomenon, since they feed on the same algal genus and only E. timida is capable of long-term kleptoplasty. Recent research has explored factors regarding functional kleptoplasty in E. timida, including their starvation longevity, digestive activity, autophagal response and photosynthetic efficiency under two different temperature conditions (18 °C and 21 °C). These studies revealed the trends E. timida displays regarding each factor during starvation as well as influences temperature has on some aspects of functional kleptoplasty. This study examines E. cornigera regarding each of these factors in an attempt to elucidate differences between each species that could explain their differing kleptoplastic abilities. Since both species naturally occur in 25 °C seawater (E. timida peak summer temperature, E. cornigera low winter temperature), each species was acclimatized to 25 °C to facilitate comparison and determine if these species exhibit physiological differences to starvation when under the same environmental conditions. Results When comparing the different E. timida temperature treatments, it becomes clear that increased temperatures compromise E. timida’s kleptoplastic abilities. Specimens acclimatized to 25 °C revealed shorter starvation longevities surviving an average 42.4 days compared to the 95.9 day average observed in specimens exposed to 18 °C. Each temperature treatment displayed a significantly different decrease throughout the starvation period in both, the rate of photosynthetic efficiency and in the decreasing functional kleptoplast abundance. Lysosomal abundances are assessed here as indicators of different aspects of metabolic activity, which could be correlated to temperature. E. cornigera, also acclimatized to 25 °C did not display significantly similar patterns as any of the E. timida temperature treatments, having fewer incorporated kleptoplasts, a higher lysosomal response to starvation, a faster decrease in photosynthetic efficiency and a lower starvation longevity. Conclusions These results confirm that each species has different physiological reactions to starvation and kleptoplast retention, even under the same conditions. While temperature affects aspects of functional kleptoplasty, it is likely not responsible for the differences in kleptoplastic abilities seen in these species. Electronic supplementary material The online version of this article (10.1186/s12983-018-0264-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elise Marie Jerschabek Laetz
- 1Zoological Research Museum Alexander Koenig, 160 Adenauerallee, 53113 Bonn, Germany.,2Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany
| | - Heike Wägele
- 1Zoological Research Museum Alexander Koenig, 160 Adenauerallee, 53113 Bonn, Germany
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Fisch KM, Hertzer C, Böhringer N, Wuisan ZG, Schillo D, Bara R, Kaligis F, Wägele H, König GM, Schäberle TF. The Potential of Indonesian Heterobranchs Found around Bunaken Island for the Production of Bioactive Compounds. Mar Drugs 2017; 15:E384. [PMID: 29215579 PMCID: PMC5742844 DOI: 10.3390/md15120384] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 01/09/2023] Open
Abstract
The species diversity of marine heterobranch sea slugs found on field trips around Bunaken Island (North Sulawesi, Indonesia) and adjacent islands of the Bunaken National Marine Park forms the basis of this review. In a survey performed in 2015, 80 species from 23 families were collected, including 17 new species. Only three of these have been investigated previously in studies from Indonesia. Combining species diversity with a former study from 2003 reveals in total 140 species from this locality. The diversity of bioactive compounds known and yet to be discovered from these organisms is summarized and related to the producer if known or suspected (might it be down the food chain, de novo synthesised from the slug or an associated bacterium). Additionally, the collection of microorganisms for the discovery of natural products of pharmacological interest from this hotspot of biodiversity that is presented here contains more than 50 species that have never been investigated before in regard to bioactive secondary metabolites. This highlights the great potential of the sea slugs and the associated microorganisms for the discovery of natural products of pharmacological interest from this hotspot of biodiversity.
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Affiliation(s)
- Katja M Fisch
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, 35392 Giessen, Germany.
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
| | - Cora Hertzer
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
| | - Nils Böhringer
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, 35392 Giessen, Germany.
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
| | - Zerlina G Wuisan
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, 35392 Giessen, Germany.
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
| | - Dorothee Schillo
- Centre of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany.
| | - Robert Bara
- Faculty of Fisheries and Marine Science, Sam Ratulangi University, Manado 95115, Indonesia.
| | - Fontje Kaligis
- Faculty of Fisheries and Marine Science, Sam Ratulangi University, Manado 95115, Indonesia.
| | - Heike Wägele
- Centre of Molecular Biodiversity, Zoological Research Museum Alexander Koenig, 53113 Bonn, Germany.
| | - Gabriele M König
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
- German Center for Infection Research, Partner Site Bonn-Cologne, 53115 Bonn, Germany.
| | - Till F Schäberle
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, 35392 Giessen, Germany.
- Institute for Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-University Bonn, 53115 Bonn, Germany.
- German Center for Infection Research, Partner Site Bonn-Cologne, 53115 Bonn, Germany.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Böhringer N, Fisch KM, Schillo D, Bara R, Hertzer C, Grein F, Eisenbarth JH, Kaligis F, Schneider T, Wägele H, König GM, Schäberle TF. Antimicrobial Potential of Bacteria Associated with Marine Sea Slugs from North Sulawesi, Indonesia. Front Microbiol 2017; 8:1092. [PMID: 28659904 PMCID: PMC5469899 DOI: 10.3389/fmicb.2017.01092] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/30/2017] [Indexed: 11/13/2022] Open
Abstract
Nudibranchia, marine soft-bodied organisms, developed, due to the absence of a protective shell, different strategies to protect themselves against putative predators and fouling organisms. One strategy is to use chemical weapons to distract predators, as well as pathogenic microorganisms. Hence, these gastropods take advantage of the incorporation of chemical molecules. Thereby the original source of these natural products varies; it might be the food source, de novo synthesis from the sea slug, or biosynthesis by associated bacteria. These bioactive molecules applied by the slugs can become important drug leads for future medicinal drugs. To test the potential of the associated bacteria, the latter were isolated from their hosts, brought into culture and extracts were prepared and tested for antimicrobial activities. From 49 isolated bacterial strains 35 showed antibiotic activity. The most promising extracts were chosen for further testing against relevant pathogens. In that way three strains showing activity against methicillin resistant Staphylococcus aureus and one strain with activity against enterohemorrhagic Escherichia coli, respectively, were identified. The obtained results indicate that the sea slug associated microbiome is a promising source for bacterial strains, which hold the potential for the biotechnological production of antibiotics.
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Affiliation(s)
- Nils Böhringer
- Institute for Pharmaceutical Biology, University of BonnBonn, Germany.,Institute for Insect Biotechnology, Justus Liebig University of GiessenGiessen, Germany
| | - Katja M Fisch
- Institute for Pharmaceutical Biology, University of BonnBonn, Germany.,Institute for Insect Biotechnology, Justus Liebig University of GiessenGiessen, Germany
| | - Dorothee Schillo
- Centre of Molecular Biodiversity, Zoological Research Museum Alexander KoenigBonn, Germany
| | - Robert Bara
- Faculty of Fisheries and Marine Science, Sam Ratulangi UniversityManado, Indonesia
| | - Cora Hertzer
- Institute for Pharmaceutical Biology, University of BonnBonn, Germany
| | - Fabian Grein
- German Center for Infection Research Partner Site Bonn-CologneBonn, Germany.,Institute of Medical Microbiology, Immunology and Parasitology - Pharmaceutical Microbiology Section, University of BonnBonn, Germany
| | - Jan-Hendrik Eisenbarth
- Centre of Molecular Biodiversity, Zoological Research Museum Alexander KoenigBonn, Germany
| | - Fontje Kaligis
- Faculty of Fisheries and Marine Science, Sam Ratulangi UniversityManado, Indonesia
| | - Tanja Schneider
- German Center for Infection Research Partner Site Bonn-CologneBonn, Germany.,Institute of Medical Microbiology, Immunology and Parasitology - Pharmaceutical Microbiology Section, University of BonnBonn, Germany
| | - Heike Wägele
- Centre of Molecular Biodiversity, Zoological Research Museum Alexander KoenigBonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of BonnBonn, Germany.,Institute of Medical Microbiology, Immunology and Parasitology - Pharmaceutical Microbiology Section, University of BonnBonn, Germany
| | - Till F Schäberle
- Institute for Pharmaceutical Biology, University of BonnBonn, Germany.,Institute for Insect Biotechnology, Justus Liebig University of GiessenGiessen, Germany.,Institute of Medical Microbiology, Immunology and Parasitology - Pharmaceutical Microbiology Section, University of BonnBonn, Germany
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Bogdanov A, Hertzer C, Kehraus S, Nietzer S, Rohde S, Schupp PJ, Wägele H, König GM. Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia). Beilstein J Org Chem 2017; 13:502-519. [PMID: 28405231 PMCID: PMC5372768 DOI: 10.3762/bjoc.13.50] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/08/2017] [Indexed: 11/23/2022] Open
Abstract
Phyllodesmium longicirrum is the largest aeolidoidean species known to date, and extremely rich in terpenoid chemistry. Herein we report the isolation of a total of 19 secondary metabolites from a single specimen of this species, i.e., steroids 1-4, cembranoid diterpenes 5-13, complex biscembranoids 14 and 15, and the chatancin-type diterpenes 16-19. These compounds resemble those from soft corals of the genus Sarcophyton, of which to date, however, only S. trocheliophorum is described as a food source for P. longicirrum. Fish feeding deterrent activity was determined using the tropical puffer fish Canthigaster solandri, and showed activity for (2S)-isosarcophytoxide (10), cembranoid bisepoxide 12 and 4-oxochatancin (16). Determining the metabolome of P. longicirrum and its bioactivity, makes it evident that this seemingly vulnerable soft bodied animal is well protected from fish by its chemical arsenal.
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Affiliation(s)
- Alexander Bogdanov
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Cora Hertzer
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Stefan Kehraus
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Samuel Nietzer
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzki University Oldenburg, Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Sven Rohde
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzki University Oldenburg, Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Peter J Schupp
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzki University Oldenburg, Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
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15
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Greve C, Ruiz-Tagle Lui M, Sivalingam S, Ludwig KU, Wägele H, Donath A. The complete mitochondrial genome of the 'solar-powered' sea slug Plakobranchus cf. ocellatus (Heterobranchia: Panpulmonata: Sacoglossa). Mitochondrial DNA B Resour 2017; 2:130-131. [PMID: 33473741 PMCID: PMC7799614 DOI: 10.1080/23802359.2016.1247667] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We present the complete mitochondrial genome sequence of Plakobranchus cf. ocellatus (Heterobranchia: Sacoglossa), a so-called ‘solar-powered’ sea slug with long-term retention of chloroplasts. The mitochondrial genome was 14,177 bp in length containing the standard set of 13 protein-coding genes, 2 rRNAs, and 22 tRNAs. The base composition of 27.3% A, 15.6% C, 18.6% G, and 38.5% T showed a strong A + T bias. The genome organization of P. cf. ocellatus is identical to the other sacoglossan mitogenomes sequenced so far, except for Ascobulla fragilis.
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Affiliation(s)
- Carola Greve
- Zoological Research Museum Alexander Koenig (ZFMK), Centre for Molecular Biodiversity Research (zmb), Bonn, Germany
| | - Maximiliano Ruiz-Tagle Lui
- Zoological Research Museum Alexander Koenig (ZFMK), Centre for Molecular Biodiversity Research (zmb), Bonn, Germany
| | - Sugirthan Sivalingam
- Life & Brain Center, Department of Genomics, University of Bonn, Bonn, Germany.,Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Kerstin U Ludwig
- Life & Brain Center, Department of Genomics, University of Bonn, Bonn, Germany.,Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Heike Wägele
- Zoological Research Museum Alexander Koenig (ZFMK), Centre for Molecular Biodiversity Research (zmb), Bonn, Germany
| | - Alexander Donath
- Zoological Research Museum Alexander Koenig (ZFMK), Centre for Molecular Biodiversity Research (zmb), Bonn, Germany
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Laetz EMJ, Moris VC, Moritz L, Haubrich AN, Wägele H. Photosynthate accumulation in solar-powered sea slugs - starving slugs survive due to accumulated starch reserves. Front Zool 2017; 14:4. [PMID: 28115976 PMCID: PMC5244517 DOI: 10.1186/s12983-016-0186-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/18/2016] [Indexed: 01/08/2023] Open
Abstract
Background Solar-powered sea slugs are famed for their ability to survive starvation due to incorporated algal chloroplasts. It is well established that algal-derived carbon can be traced in numerous slug-derived compounds, showing that slugs utilize the photosynthates produced by incorporated plastids. Recently, a new hypothesis suggests that the photosynthates produced are not continuously made available to the slug. Instead, at least some of the plastid’s photosynthetic products are stored in the plastid itself and only later become available to the slug. The long-term plastid-retaining slug, Elysia timida and its sole food source, Acetabularia acetabulum were examined to determine whether or not starch, a combination of amylose and amylopectin and the main photosynthate produced by A. acetabulum, is produced by the stolen plastids and whether it accumulates within individual kleptoplasts, providing an energy larder, made available to the slug at a later time. Results Histological sections of Elysia timida throughout a starvation period were stained with Lugol’s Iodine solution, a well-known stain for starch granules in plants. We present here for the first time, an increase in amylose concentration, within the slug’s digestive gland cells during a starvation period, followed by a sharp decrease. Chemically blocking photosynthesis in these tissues resulted in no observable starch, indicating that the starch in untreated animals is a product of photosynthetic activity. Conclusion This suggests that kleptoplasts function as both, a nutritive producer and storage device, holding onto the polysaccharides they produce for a certain time until they are finally available and used by the starving slug to withstand extended starvation periods.
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Affiliation(s)
- Elise M J Laetz
- Zoological Research Museum Alexander Koenig, 162 Adenauerallee, Bonn, 53113 Germany.,Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, Bonn, 53121 Germany
| | - Victoria C Moris
- Zoological Research Museum Alexander Koenig, 162 Adenauerallee, Bonn, 53113 Germany
| | - Leif Moritz
- Zoological Research Museum Alexander Koenig, 162 Adenauerallee, Bonn, 53113 Germany
| | - André N Haubrich
- Zoological Research Museum Alexander Koenig, 162 Adenauerallee, Bonn, 53113 Germany
| | - Heike Wägele
- Zoological Research Museum Alexander Koenig, 162 Adenauerallee, Bonn, 53113 Germany
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Moles J, Wägele H, Uhl G, Avila C. Bipolarity in sea slugs: a new species of Doridunculus (Mollusca: Nudibranchia: Onchidoridoidea) from Antarctica. ORG DIVERS EVOL 2016. [DOI: 10.1007/s13127-016-0309-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Laetz EMJ, Rühr PT, Bartolomaeus T, Preisfeld A, Wägele H. Examining the retention of functional kleptoplasts and digestive activity in sacoglossan sea slugs. ORG DIVERS EVOL 2016. [DOI: 10.1007/s13127-016-0308-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Affiliation(s)
- Juan Moles
- Department of Animal Biology (Invertebrates) and Biodiversity Research Institute (IrBIO); University of Barcelona; Avinguda Diagonal 643 08028 Barcelona Catalonia Spain
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig; Adenauerallee 160 53113 Bonn Germany
| | - Michael Schrödl
- SNSB Bavarian State Collection of Zoology; Münchhausenstraße 21 81247 Munich Germany
- Biozentrum and GeoBio Center Ludwig Maximilians Universität München; Munich Germany
| | - Conxita Avila
- Department of Animal Biology (Invertebrates) and Biodiversity Research Institute (IrBIO); University of Barcelona; Avinguda Diagonal 643 08028 Barcelona Catalonia Spain
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Moles J, Wägele H, Ballesteros M, Pujals Á, Uhl G, Avila C. The End of the Cold Loneliness: 3D Comparison between Doto antarctica and a New Sympatric Species of Doto (Heterobranchia: Nudibranchia). PLoS One 2016; 11:e0157941. [PMID: 27411060 PMCID: PMC4943632 DOI: 10.1371/journal.pone.0157941] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 06/07/2016] [Indexed: 11/20/2022] Open
Abstract
Although several studies are devoted to determining the diversity of Antarctic heterobranch sea slugs, new species are still being discovered. Among nudibranchs, Doto antarctica Eliot, 1907 is the single species of this genus described from Antarctica hitherto, the type locality being the Ross Sea. Doto antarctica was described mainly using external features. During our Antarctic research on marine benthic invertebrates, we found D. antarctica in the Weddell Sea and Bouvet Island, suggesting a circumpolar distribution. Species affiliation is herein supported by molecular analyses using cytochrome c oxidase subunit I, 16S rRNA, and histone H3 markers. We redescribe D. antarctica using histology, micro-computed tomography (micro-CT), and 3D-reconstruction of the internal organs. Moreover, we describe a new, sympatric species, namely D. carinova Moles, Avila & Wägele n. sp., and provide an anatomical comparison between the two Antarctic Doto species. Egg masses in both species are also described here for the first time. We demonstrate that micro-CT is a useful tool for non-destructive anatomical description of valuable specimens. Furthermore, our high resolution micro-CT data reveal that the central nervous system of both Doto species possesses numerous accessory giant cells, suggested to be neurons herein. In addition, the phylogenetic tree of all Doto species sequenced to date suggests a scenario for the evolution of the reproductive system in this genus: bursa copulatrix seems to have been reduced and the acquisition of a distal connection of the oviduct to the nidamental glands is a synapomorphy of the Antarctic Doto species. Overall, the combination of thorough morphological and anatomical description and molecular analyses provides a comprehensive means to characterize and delineate species, thus suggesting evolutionary scenarios.
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Affiliation(s)
- Juan Moles
- Department of Evolutionary Biology, Ecology, and Environmental Sciences and Biodiversity Research Institute (IrBIO), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain
| | - Heike Wägele
- Zoological Research Museum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - Manuel Ballesteros
- Department of Evolutionary Biology, Ecology, and Environmental Sciences and Biodiversity Research Institute (IrBIO), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain
| | - Álvaro Pujals
- Department of Evolutionary Biology, Ecology, and Environmental Sciences and Biodiversity Research Institute (IrBIO), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain
| | - Gabriele Uhl
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Anklamer Str. 20, 17489 Greifswald, Germany
| | - Conxita Avila
- Department of Evolutionary Biology, Ecology, and Environmental Sciences and Biodiversity Research Institute (IrBIO), University of Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain
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Bogdanov A, Hertzer C, Kehraus S, Nietzer S, Rohde S, Schupp PJ, Wägele H, König GM. Defensive Diterpene from the Aeolidoidean Phyllodesmium longicirrum. J Nat Prod 2016; 79:611-615. [PMID: 26649919 DOI: 10.1021/acs.jnatprod.5b00860] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Phyllodesmium is a tropical marine slug genus with about 30 described species. None of them have a protective shell, and all of them feed on octocorals that are generally known to provide defensive compounds and thus help to defend the naked slugs against sympatric predators, such as fish, crabs, cephalopods, and echinoderms. Phyllodesmium longicirrum is the species that grows the biggest and that is least protected by camouflage on its respective food, usually a soft coral of the genus Sarcophyton. Investigation of the lipophilic extract of a single specimen of P. longicirrum from the Great Barrier Reef (Australia) led to the isolation of four new polycyclic diterpenes. Compound 1 showed significant deterrent activity in a fish feeding assay.
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Affiliation(s)
- Alexander Bogdanov
- Institute for Pharmaceutical Biology, University of Bonn , Nussallee 6, 53115 Bonn, Germany
| | - Cora Hertzer
- Institute for Pharmaceutical Biology, University of Bonn , Nussallee 6, 53115 Bonn, Germany
| | - Stefan Kehraus
- Institute for Pharmaceutical Biology, University of Bonn , Nussallee 6, 53115 Bonn, Germany
| | - Samuel Nietzer
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University Oldenburg , Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Sven Rohde
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University Oldenburg , Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Peter J Schupp
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University Oldenburg , Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig , Adenauerallee 160, 53113 Bonn, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn , Nussallee 6, 53115 Bonn, Germany
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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de Vries J, Woehle C, Christa G, Wägele H, Tielens AGM, Jahns P, Gould SB. Comparison of sister species identifies factors underpinning plastid compatibility in green sea slugs. Proc Biol Sci 2015; 282:rspb.2014.2519. [PMID: 25652835 PMCID: PMC4344150 DOI: 10.1098/rspb.2014.2519] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The only animal cells known that can maintain functional plastids (kleptoplasts) in their cytosol occur in the digestive gland epithelia of sacoglossan slugs. Only a few species of the many hundred known can profit from kleptoplasty during starvation long-term, but why is not understood. The two sister taxa Elysia cornigera and Elysia timida sequester plastids from the same algal species, but with a very different outcome: while E. cornigera usually dies within the first two weeks when deprived of food, E. timida can survive for many months to come. Here we compare the responses of the two slugs to starvation, blocked photosynthesis and light stress. The two species respond differently, but in both starvation is the main denominator that alters global gene expression profiles. The kleptoplasts' ability to fix CO2 decreases at a similar rate in both slugs during starvation, but only E. cornigera individuals die in the presence of functional kleptoplasts, concomitant with the accumulation of reactive oxygen species (ROS) in the digestive tract. We show that profiting from the acquisition of robust plastids, and key to E. timida's longer survival, is determined by an increased starvation tolerance that keeps ROS levels at bay.
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Affiliation(s)
- Jan de Vries
- Institute of Molecular Evolution, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Christian Woehle
- Institute of Molecular Evolution, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Gregor Christa
- Institute of Molecular Evolution, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - Aloysius G M Tielens
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Peter Jahns
- Plant Biochemistry and Stress Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany
| | - Sven B Gould
- Institute of Molecular Evolution, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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25
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Laetz E, Christa G, Händeler K, Wägele H. The Cylindrobulla/Ascobulla complex--unraveling problems in identification and adding to Cylindrobulla diversity (Gastropoda, Heterobranchia, Sacoglossa) by describing a new species. Zootaxa 2014; 3893:339-62. [PMID: 25544526 DOI: 10.11646/zootaxa.3893.3.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Indexed: 11/04/2022]
Abstract
Sacoglossa (Gastropoda: Heterobranchia) are generally considered a monophyletic group, previously associated within the now defunct "Opisthobranchia", but now basally located within Panpulmonata. In the light of this new phylogenetic hypothesis, detailed knowledge of the most basal groups within Sacoglossa is of paramount importance. This study focuses on the genus Cylindrobulla, which is usually considered the most basal group within the Sacoglossa from a morphological point of view, because it does not share the typical elongate radula teeth of all other Sacoglossa. We describe a new species, Cylindrobulla schuppi sp. nov., and provide data on its food. We reexamined and clarify the radula of the type species C. beauii, review the genus with all other valid species, provide new characters to aid in the proper identification of species within this genus, compare it to the very similar genus Ascobulla, present a determination key using external characters to ensure proper identification of the two similar genera, and discuss phylogenetic relationships within the shelled sacoglossan, the Oxynoacea.
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Affiliation(s)
- Elise Laetz
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.;
| | - Gregor Christa
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.;
| | - Katharina Händeler
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.;
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.;
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26
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Bogdanov A, Kehraus S, Bleidissel S, Preisfeld G, Schillo D, Piel J, Brachmann AO, Wägele H, König GM. Defense in the aeolidoidean genus Phyllodesmium (Gastropoda). J Chem Ecol 2014; 40:1013-24. [PMID: 25244950 DOI: 10.1007/s10886-014-0496-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/03/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
Abstract
The genus Phyllodesmium (Aeolidoidea, Gastropoda) comprises shell-less marine snails, whose defense strategies are not well investigated yet. Here we report results of the first chemical investigation of P. briareum, as well as a re-investigation of P. longicirrum and P. magnum. Briarane diterpenes were isolated from P. briareum, and their origin could be traced to its prey organism Briareum sp. (Octocorallia). Considerable enrichment of the soft coral secondary metabolites in the slug was shown. Re-investigation of P. magnum led to isolation of cembrane diterpenes, 2-phenylethylamide, and furano sesquiterpenes. Sequestration of chemicals seems to have influenced speciation and evolution of Phyllodesmium species. Structural similarity or dissimilarity of particular slug metabolites suggests a closer, or more distant relationship of the respective Phyllodesmium taxa.
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Affiliation(s)
- Alexander Bogdanov
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
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de Vries J, Habicht J, Woehle C, Huang C, Christa G, Wägele H, Nickelsen J, Martin WF, Gould SB. Is ftsH the key to plastid longevity in sacoglossan slugs? Genome Biol Evol 2014; 5:2540-8. [PMID: 24336424 PMCID: PMC3879987 DOI: 10.1093/gbe/evt205] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Plastids sequestered by sacoglossan sea slugs have long been a puzzle. Some sacoglossans feed on siphonaceous algae and can retain the plastids in the cytosol of their digestive gland cells. There, the stolen plastids (kleptoplasts) can remain photosynthetically active in some cases for months. Kleptoplast longevity itself challenges current paradigms concerning photosystem turnover, because kleptoplast photosystems remain active in the absence of nuclear algal genes. In higher plants, nuclear genes are essential for plastid maintenance, in particular, for the constant repair of the D1 protein of photosystem II. Lateral gene transfer was long suspected to underpin slug kleptoplast longevity, but recent transcriptomic and genomic analyses show that no algal nuclear genes are expressed from the slug nucleus. Kleptoplast genomes themselves, however, appear expressed in the sequestered state. Here we present sequence data for the chloroplast genome of Acetabularia acetabulum, the food source of the sacoglossan Elysia timida, which can maintain Acetabularia kleptoplasts in an active state for months. The data reveal what might be the key to sacoglossan kleptoplast longevity: plastids that remain photosynthetically active within slugs for periods of months share the property of encoding ftsH, a D1 quality control protease that is essential for photosystem II repair. In land plants, ftsH is always nuclear encoded, it was transferred to the nucleus from the plastid genome when Charophyta and Embryophyta split. A replenishable supply of ftsH could, in principle, rescue kleptoplasts from D1 photodamage, thereby influencing plastid longevity in sacoglossan slugs.
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Affiliation(s)
- Jan de Vries
- Institute of Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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28
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Schmitt V, Händeler K, Gunkel S, Escande ML, Menzel D, Gould SB, Martin WF, Wägele H. Chloroplast incorporation and long-term photosynthetic performance through the life cycle in laboratory cultures of Elysia timida (Sacoglossa, Heterobranchia). Front Zool 2014; 11:5. [PMID: 24428892 PMCID: PMC3898781 DOI: 10.1186/1742-9994-11-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/10/2014] [Indexed: 11/30/2022] Open
Abstract
Introduction The Mediterranean sacoglossan Elysia timida is one of the few sea slug species with the ability to sequester chloroplasts from its food algae and to subsequently store them in a functional state in the digestive gland cells for more than a month, during which time the plastids retain high photosynthetic activity (= long-term retention). Adult E. timida have been described to feed on the unicellular alga Acetabularia acetabulum in their natural environment. The suitability of E. timida as a laboratory model culture system including its food source was studied. Results In contrast to the literature reporting that juvenile E. timida feed on Cladophora dalmatica first, and later on switch to the adult diet A. acetabulum, the juveniles in this study fed directly on A. acetabulum (young, non-calcified stalks); they did not feed on the various Cladophora spp. (collected from the sea or laboratory culture) offered. This could possibly hint to cryptic speciation with no clear morphological differences, but incipient ecological differentiation. Transmission electron microscopy of chloroplasts from A. acetabulum after initial intake by juvenile E. timida showed different states of degradation — in conglomerations or singularly — and fragments of phagosome membranes, but differed from kleptoplast images of C. dalmatica in juvenile E. timida from the literature. Based on the finding that the whole life cycle of E. timida can be completed with A. acetabulum as the sole food source, a laboratory culture system was established. An experiment with PAM-fluorometry showed that cultured E. timida are also able to store chloroplasts in long-term retention from Acetabularia peniculus, which stems from the Indo-Pacific and is not abundant in the natural environment of E. timida. Variations between three experiment groups indicated potential influences of temperature on photosynthetic capacities. Conclusions E. timida is a viable laboratory model system to study photosynthesis in incorporated chloroplasts (kleptoplasts). Capacities of chloroplast incorporation in E. timida were investigated in a closed laboratory culture system with two different chloroplast donors and over extended time periods about threefold longer than previously reported.
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Affiliation(s)
| | | | | | | | | | | | | | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.
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29
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Christa G, Zimorski V, Woehle C, Tielens AGM, Wägele H, Martin WF, Gould SB. Plastid-bearing sea slugs fix CO2 in the light but do not require photosynthesis to survive. Proc Biol Sci 2013; 281:20132493. [PMID: 24258718 DOI: 10.1098/rspb.2013.2493] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Several sacoglossan sea slugs (Plakobranchoidea) feed upon plastids of large unicellular algae. Four species--called long-term retention (LtR) species--are known to sequester ingested plastids within specialized cells of the digestive gland. There, the stolen plastids (kleptoplasts) remain photosynthetically active for several months, during which time LtR species can survive without additional food uptake. Kleptoplast longevity has long been puzzling, because the slugs do not sequester algal nuclei that could support photosystem maintenance. It is widely assumed that the slugs survive starvation by means of kleptoplast photosynthesis, yet direct evidence to support that view is lacking. We show that two LtR plakobranchids, Elysia timida and Plakobranchus ocellatus, incorporate (14)CO2 into acid-stable products 60- and 64-fold more rapidly in the light than in the dark, respectively. Despite this light-dependent CO2 fixation ability, light is, surprisingly, not essential for the slugs to survive starvation. LtR animals survived several months of starvation (i) in complete darkness and (ii) in the light in the presence of the photosynthesis inhibitor monolinuron, all while not losing weight faster than the control animals. Contrary to current views, sacoglossan kleptoplasts seem to be slowly digested food reserves, not a source of solar power.
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Affiliation(s)
- Gregor Christa
- Zoologisches Forschungsmuseum Alexander Koenig, Centre for Molecular Biodiversity Research (zmb), , Bonn 53113, Germany, Institute for Molecular Evolution, Heinrich Heine-University Düsseldorf, , Düsseldorf 40225, Germany, Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, , Utrecht, The Netherlands, Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, , Rotterdam, The Netherlands
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Händeler K, Wägele H, Wahrmund U, Rüdinger M, Knoop V. Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda). Mol Ecol Resour 2013; 10:968-78. [PMID: 21565106 DOI: 10.1111/j.1755-0998.2010.02853.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter.
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Affiliation(s)
- Katharina Händeler
- Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany Institut für Zelluläre und Molekulare Botanik, Bonn, Germany
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Christa G, Wescott L, Schäberle TF, König GM, Wägele H. What remains after 2 months of starvation? Analysis of sequestered algae in a photosynthetic slug, Plakobranchus ocellatus (Sacoglossa, Opisthobranchia), by barcoding. Planta 2013; 237:559-572. [PMID: 23108662 DOI: 10.1007/s00425-012-1788-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/04/2012] [Indexed: 05/28/2023]
Abstract
The sacoglossan sea slug, Plakobranchus ocellatus, is a so-called long-term retention form that incorporates chloroplasts for several months and thus is able to starve while maintaining photosynthetic activity. Little is known regarding the taxonomy and food sources of this sacoglossan, but it is suggested that P. ocellatus is a species complex and feeds on a broad variety of Ulvophyceae. In particular, we analysed specimens from the Philippines and starved them under various light conditions (high light, low light and darkness) and identified the species of algal food sources depending on starvation time and light treatment by means of DNA-barcoding using for the first time the combination of two algal chloroplast markers, rbcL and tufA. Comparison of available CO1 and 16S sequences of specimens from various localities indicate a species complex with likely four distinct clades, but food analyses do not indicate an ecological separation of the investigated clades into differing foraging strategies. The combined results from both algal markers suggest that, in general, P. ocellatus has a broad food spectrum, including members of the genera Halimeda, Caulerpa, Udotea, Acetabularia and further unidentified algae, with an emphasis on H. macroloba. Independent of the duration of starvation and light exposure, this algal species and a further unidentified Halimeda species seem to be the main food source of P. ocellatus from the Philippines. It is shown here that at least two (or possibly three) barcode markers are required to cover the entire food spectrum in future analyses of Sacoglossa.
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Affiliation(s)
- Gregor Christa
- Forschungsmuseum Alexander Koenig, Adenauerallee 160, Bonn, Germany
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32
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Obermann D, Bickmeyer U, Wägele H. Incorporated nematocysts in Aeolidiella stephanieae (Gastropoda, Opisthobranchia, Aeolidoidea) mature by acidification shown by the pH sensitive fluorescing alkaloid Ageladine A. Toxicon 2012; 60:1108-16. [DOI: 10.1016/j.toxicon.2012.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/02/2012] [Accepted: 08/07/2012] [Indexed: 11/16/2022]
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Huelsken T, Tapken D, Dahlmann T, Wägele H, Riginos C, Hollmann M. Systematics and phylogenetic species delimitation within Polinices s.l. (Caenogastropoda: Naticidae) based on molecular data and shell morphology. ORG DIVERS EVOL 2012. [DOI: 10.1007/s13127-012-0111-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wägele H, Klussmann-Kolb A, Kuhlmann M, Haszprunar G, Lindberg D, Koch A, Wägele JW. The taxonomist - an endangered race. A practical proposal for its survival. Front Zool 2011; 8:25. [PMID: 22029904 PMCID: PMC3210083 DOI: 10.1186/1742-9994-8-25] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 10/26/2011] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Taxonomy or biological systematics is the basic scientific discipline of biology, postulating hypotheses of identity and relationships, on which all other natural sciences dealing with organisms relies. However, the scientific contributions of taxonomists have been largely neglected when using species names in scientific publications by not citing the authority on which they are based. DISCUSSION Consequences of this neglect is reduced recognition of the importance of taxonomy, which in turn results in diminished funding, lower interest from journals in publishing taxonomic research, and a reduced number of young scientists entering the field. This has lead to the so-called taxonomic impediment at a time when biodiversity studies are of critical importance.Here we emphasize a practical and obvious solution to this dilemma. We propose that whenever a species name is used, the author(s) of the species hypothesis be included and the original literature source cited, including taxonomic revisions and identification literature - nothing more than what is done for every other hypothesis or assumption included in a scientific publication. In addition, we postulate that journals primarily publishing taxonomic studies should be indexed in ISISM. SUMMARY The proposal outlined above would make visible the true contribution of taxonomists within the scientific community, and would provide a more accurate assessment for funding agencies impact and importance of taxonomy, and help in the recruitment of young scientists into the field, thus helping to alleviate the taxonomic impediment. In addition, it would also make much of the biological literature more robust by reducing or alleviating taxonomic uncertainty.
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Affiliation(s)
- Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - Annette Klussmann-Kolb
- Institute for Ecology, Evolution and Diversity, Goethe-University, Siesmayerstrasse 70, 60054 Frankfurt am Main, Germany
| | - Michael Kuhlmann
- Department of Entomology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Gerhard Haszprunar
- Zoologische Staatssammlung München, Münchhausenstraße 21, 81247 München, Germany
| | - David Lindberg
- Department of Integrative Biology and Museum of Paleontology, University of California, Berkeley, CA 94720-4780, USA
| | - André Koch
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
| | - J Wolfgang Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany
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35
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Putz A, Kehraus S, Díaz-Agras G, Wägele H, König GM. Dotofide, a Guanidine-Interrupted Terpenoid from the Marine Slug Doto pinnatifida (Gastropoda, Nudibranchia). European J Org Chem 2011. [DOI: 10.1002/ejoc.201100347] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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36
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Wägele H, Deusch O, Händeler K, Martin R, Schmitt V, Christa G, Pinzger B, Gould SB, Dagan T, Klussmann-Kolb A, Martin W. Transcriptomic evidence that longevity of acquired plastids in the photosynthetic slugs Elysia timida and Plakobranchus ocellatus does not entail lateral transfer of algal nuclear genes. Mol Biol Evol 2010; 28:699-706. [PMID: 20829345 PMCID: PMC3002249 DOI: 10.1093/molbev/msq239] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Sacoglossan sea slugs are unique in the animal kingdom in that they sequester and maintain active plastids that they acquire from the siphonaceous algae upon which they feed, making the animals photosynthetic. Although most sacoglossan species digest their freshly ingested plastids within hours, four species from the family Plakobranchidae retain their stolen plastids (kleptoplasts) in a photosynthetically active state on timescales of weeks to months. The molecular basis of plastid maintenance within the cytosol of digestive gland cells in these photosynthetic metazoans is yet unknown but is widely thought to involve gene transfer from the algal food source to the slugs based upon previous investigations of single genes. Indeed, normal plastid development requires hundreds of nuclear-encoded proteins, with protein turnover in photosystem II in particular known to be rapid under various conditions. Moreover, only algal plastids, not the algal nuclei, are sequestered by the animals during feeding. If algal nuclear genes are transferred to the animal either during feeding or in the germ line, and if they are expressed, then they should be readily detectable with deep-sequencing methods. We have sequenced expressed mRNAs from actively photosynthesizing, starved individuals of two photosynthetic sea slug species, Plakobranchus ocellatus Van Hasselt, 1824 and Elysia timida Risso, 1818. We find that nuclear-encoded, algal-derived genes specific to photosynthetic function are expressed neither in P. ocellatus nor in E. timida. Despite their dramatic plastid longevity, these photosynthetic sacoglossan slugs do not express genes acquired from algal nuclei in order to maintain plastid function.
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Affiliation(s)
- Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany.
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Händeler K, Grzymbowski YP, Krug PJ, Wägele H. Functional chloroplasts in metazoan cells - a unique evolutionary strategy in animal life. Front Zool 2009; 6:28. [PMID: 19951407 PMCID: PMC2790442 DOI: 10.1186/1742-9994-6-28] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 12/01/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Among metazoans, retention of functional diet-derived chloroplasts (kleptoplasty) is known only from the sea slug taxon Sacoglossa (Gastropoda: Opisthobranchia). Intracellular maintenance of plastids in the slug's digestive epithelium has long attracted interest given its implications for understanding the evolution of endosymbiosis. However, photosynthetic ability varies widely among sacoglossans; some species have no plastid retention while others survive for months solely on photosynthesis. We present a molecular phylogenetic hypothesis for the Sacoglossa and a survey of kleptoplasty from representatives of all major clades. We sought to quantify variation in photosynthetic ability among lineages, identify phylogenetic origins of plastid retention, and assess whether kleptoplasty was a key character in the radiation of the Sacoglossa. RESULTS Three levels of photosynthetic activity were detected: (1) no functional retention; (2) short-term retention lasting about one week; and (3) long-term retention for over a month. Phylogenetic analysis of one nuclear and two mitochondrial loci revealed reciprocal monophyly of the shelled Oxynoacea and shell-less Plakobranchacea, the latter comprising a monophyletic Plakobranchoidea and paraphyletic Limapontioidea. Only species in the Plakobranchoidea expressed short- or long-term kleptoplasty, most belonging to a speciose clade of slugs bearing parapodia (lateral flaps covering the dorsum). Bayesian ancestral character state reconstructions indicated that functional short-term retention arose once in the last common ancestor of Plakobranchoidea, and independently evolved into long-term retention in four derived species. CONCLUSION We propose a sequential progression from short- to long-term kleptoplasty, with different adaptations involved in each step. Short-term kleptoplasty likely arose as a deficiency in plastid digestion, yielding additional energy via the release of fixed carbon. Functional short-term retention was an apomorphy of the Plakobranchoidea, but the subsequent evolution of parapodia enabled slugs to protect kleptoplasts against high irradiance and further prolong plastid survival. We conclude that functional short-term retention was necessary but not sufficient for an adaptive radiation in the Plakobranchoidea, especially in the genus Elysia which comprises a third of all sacoglossan species. The adaptations necessary for long-term chloroplast survival arose independently in species feeding on different algal hosts, providing a valuable study system for examining the parallel evolution of this unique trophic strategy.
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Affiliation(s)
- Katharina Händeler
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany.
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Wägele JW, Letsch H, Klussmann-Kolb A, Mayer C, Misof B, Wägele H. Phylogenetic support values are not necessarily informative: the case of the Serialia hypothesis (a mollusk phylogeny). Front Zool 2009; 6:12. [PMID: 19555513 PMCID: PMC2710323 DOI: 10.1186/1742-9994-6-12] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 06/26/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Molecular phylogenies are being published increasingly and many biologists rely on the most recent topologies. However, different phylogenetic trees often contain conflicting results and contradict significant background data. Not knowing how reliable traditional knowledge is, a crucial question concerns the quality of newly produced molecular data. The information content of DNA alignments is rarely discussed, as quality statements are mostly restricted to the statistical support of clades. Here we present a case study of a recently published mollusk phylogeny that contains surprising groupings, based on five genes and 108 species, and we apply new or rarely used tools for the analysis of the information content of alignments and for the filtering of noise (masking of random-like alignment regions, split decomposition, phylogenetic networks, quartet mapping). RESULTS The data are very fragmentary and contain contaminations. We show that that signal-like patterns in the data set are conflicting and partly not distinct and that the reported strong support for a "rather surprising result" (monoplacophorans and chitons form a monophylum Serialia) does not exist at the level of primary homologies. Split-decomposition, quartet mapping and neighbornet analyses reveal conflicting nucleotide patterns and lack of distinct phylogenetic signal for the deeper phylogeny of mollusks. CONCLUSION Even though currently a majority of molecular phylogenies are being justified with reference to the 'statistical' support of clades in tree topologies, this confidence seems to be unfounded. Contradictions between phylogenies based on different analyses are already a strong indication of unnoticed pitfalls. The use of tree-independent tools for exploratory analyses of data quality is highly recommended. Concerning the new mollusk phylogeny more convincing evidence is needed.
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Affiliation(s)
- J Wolfgang Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53313 Bonn, Germany
| | - Harald Letsch
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53313 Bonn, Germany
| | - Annette Klussmann-Kolb
- J. W. Goethe University, Institute for Ecology, Evolution and Diversity, Siesmayerstrasse 70, D – 60054 Frankfurt am Main, Germany
| | - Christoph Mayer
- Ruhr-University Bochum, Faculty of Biology, Universitätsstr., 44370 Bochum, Germany
| | - Bernhard Misof
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53313 Bonn, Germany
| | - Heike Wägele
- Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53313 Bonn, Germany
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Wägele H. Die Gattung Bathydoris Bergh, 1884 (Gnathodoridacea) im phylogenetischen System der Nudibranchia (Opisthobranchia, Gastropoda). J ZOOL SYST EVOL RES 2009. [DOI: 10.1111/j.1439-0469.1989.tb00350.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The recently discovered new aeolidean species Phyllodesmium lizardensis Burghardt, Schrodl and Wagele, 2008 was investigated concerning its secondary metabolite profile. P. lizardensis so far has only been found on Lizard Island. Analysis of P. lizardensis led to the isolation of the new sesquiterpenes (+)-3beta-hydroxy-alpha-muurolene (1) and (+)-3beta-acetoxy-alpha-muurolene (2). GC-MS analysis of the host coral, identified as Heteroxenia sp., also showed the presence of compounds 1 and 2, whereas a sympatric Xenia species lacks these products. These results indicate that P. lizardensis specifically sequesters these compounds from Heteroxenia sp.
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Affiliation(s)
- Sven Affeld
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115 Bonn, Germany
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Kiko R, Kramer M, Spindler M, Wägele H. Tergipes antarcticus (Gastropoda, Nudibranchia): distribution, life cycle, morphology, anatomy and adaptation of the first mollusc known to live in Antarctic sea ice. Polar Biol 2008. [DOI: 10.1007/s00300-008-0478-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Burghardt I, Wägele H. Interspecific differences in the efficiency and photosynthetic characteristics of the symbiosis of "solarpowered" Nudibranchia (Mollusca: Gastropoda) with zooxanthellae. ACTA ACUST UNITED AC 2006. [DOI: 10.18195/issn.0313-122x.69.2006.001-009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Wägele H, Klussmann-Kolb A. Opisthobranchia (Mollusca, Gastropoda) - more than just slimy slugs. Shell reduction and its implications on defence and foraging. Front Zool 2005; 2:3. [PMID: 15715915 PMCID: PMC554092 DOI: 10.1186/1742-9994-2-3] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Accepted: 02/16/2005] [Indexed: 11/16/2022] Open
Abstract
Background In general shell-less slugs are considered to be slimy animals with a rather dull appearance and a pest to garden plants. But marine slugs usually are beautifully coloured animals belonging to the less-known Opisthobranchia. They are characterized by a large array of interesting biological phenomena, usually related to foraging and/or defence. In this paper our knowledge of shell reduction, correlated with the evolution of different defensive and foraging strategies is reviewed, and new results on histology of different glandular systems are included. Results Based on a phylogeny obtained by morphological and histological data, the parallel reduction of the shell within the different groups is outlined. Major food sources are given and glandular structures are described as possible defensive structures in the external epithelia, and as internal glands. Conclusion According to phylogenetic analyses, the reduction of the shell correlates with the evolution of defensive strategies. Many different kinds of defence structures, like cleptocnides, mantle dermal formations (MDFs), and acid glands, are only present in shell-less slugs. In several cases, it is not clear whether the defensive devices were a prerequisite for the reduction of the shell, or reduction occurred before. Reduction of the shell and acquisition of different defensive structures had an implication on exploration of new food sources and therefore likely enhanced adaptive radiation of several groups.
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Affiliation(s)
- Heike Wägele
- Museum König Bonn, Adenaueralle 160, 53113 Bonn, Germany
- Institut für Evolutionsbiologie, Rheinische Friedrich-Wilhelms-Universität, An der Immenburg 1, 53121 Bonn, Germany
| | - Annette Klussmann-Kolb
- Zoologisches Institut, J.W. Goethe Universität, Siesmayerstrasse 70, 60054 Frankfurt, Germany
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Abstract
The major organ systems of Goniodoris castanea were investigated by histological means, with an emphasis on those structures that are difficult to see by dissection. The species is characterized by some peculiar features that are unique or seldom within the Nudibranchia, such as the complete absence of specialized vacuolated cells, the presence of globular salivary glands, the presence of cuticular structures in the proximal intestine, a muscular sphincter around the distal vaginal duct, and the position of the blood gland closer to the pericardium than to the nervous system. Some of these characters are discussed in a phylogenetic context, although a thorough phylogenetic analysis is preliminary, due to lack of knowledge of probably related species.
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Affiliation(s)
- H Wägele
- Lehrstuhl für Spezielle Zoologie, Ruhr-Universität Bochum, Bochum, Germany.
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Schrödl M, Wägele H, Willan RC. Taxonomic Redescription of the Doridoxidae(Gastropoda: Opisthobranchia), an Enigmatic Family of Deep Water Nudibranchs, with Discussion of Basal Nudibranch Phylogeny. ZOOL ANZ 2001. [DOI: 10.1078/0044-5231-00008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Wollscheid E, Wägele H. Initial results on the molecular phylogeny of the Nudibranchia (Gastropoda, Opisthobranchia) based on 18S rDNA data. Mol Phylogenet Evol 1999; 13:215-26. [PMID: 10603252 DOI: 10.1006/mpev.1999.0664] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated nudibranch phylogeny on the basis of 18S rDNA sequence data. 18S rDNA sequence data of 19 taxa representing the major living orders and families of the Nudibranchia were analyzed. Representatives of the Cephalaspidea, Anaspidea, Gymnomorpha, Prosobranchia, and Pulmonata were also sequenced and used as outgroups. An additional 28 gastropod sequences taken from GenBank were also included in our analyses. Phylogenetic analyses of these more than 50 gastropod taxa provide strong evidence for support of the monophyly of the Nudibranchia. The monophyly of the Doridoidea, Cladobranchia, and Aeolidoidea within the Nudibranchia are also strongly supported. Phylogenetic utility and information content of the 18S rDNA sequences for Nudibranchia, and Opisthobranchia in general, are examined using the program SplitsTree as well as phylogenetic reconstructions using distance and parsimony approaches. 0Results based on these molecular data are compared with hypotheses about nudibranch phylogeny inferred from morphological data.
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Affiliation(s)
- E Wollscheid
- Department of Cell & Developmental Biology, University of Pennsylvania School of Medicine, 1157 Biomedical Research Building II/III, 421 Curie Blvd., Philadelphia, Pennsylvania, 19104-6058, USA
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Wägele H, Brodie GD, Klussmann-Kolb A. Histological investigations on Dendrodoris nigra (Stimpson, 1855) (Gastropoda, Nudibranchia, Dendrodorididae). Molluscan Research 1999. [DOI: 10.1080/13235818.1999.10673725] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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