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Bastian Bentlage - One of the best experts on this subject based on the ideXlab platform.
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Transcription/translation of mt genome in the box jellyfishA. alata (Cnidaria: Cubozoa)
2016Co-Authors: Bastian BentlageAbstract:Fasta and GFF files containing sequence and annotations of genes involved in the transcription and translation of Alatina alata's (box jellyfish) linear mt genome chromosomes. In addition, the (almost) complete mt genome is included in the fileset.This dataset accompanies the following publication:Kayal E, Bnetlage B, Collins AG (2016) Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa). RNA Biology, in press.DOI: 10.1080/15476286.2016.119416
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Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa)
2016Co-Authors: Ehsan Kayal, Bastian Bentlage, Allen G. CollinsAbstract:Background: In most animals, the mitochondrial genome is characterized by its small size, organization into a single circular molecule, and a relative conservation of the number of encoded genes. In box jellyfish (Cubozoa, Cnidaria), the mitochondrial genome is organized into 8 linear mito-chromosomes harboring between one and 4 genes each, including 2 extra protein-coding genes: mt-polB and orf314. Such an organization challenges the traditional view of mitochondrial DNA (mtDNA) expression in animals. In this study, we investigate the pattern of mitochondrial gene expression in the box jellyfish Alatina alata, as well as several key nuclear-encoded molecular pathways involved in the processing of mitochondrial gene transcription. Results: Read coverage of DNA-seq data is relatively uniform for all 8 mito-chromosomes, suggesting that each mito-chromosome is present in equimolar proportion in the mitochondrion. Comparison of DNA and RNA-seq based assemblies indicates that mito-chromosomes are transcribed into individual transcripts in which the beginning and ending are highly conserved. Expression levels for mt-polB and orf314 are similar to those of other mitochondrial-encoded genes, which provides further evidence for them having functional roles in the mitochondrion. Survey of the transcriptome suggests recognition of the mitochondrial tRNA-Met by the cytoplasmic aminoacyl-tRNA synthetase counterpart and C-to-U editing of the cytoplasmic tRNA-Trp after import into the mitochondrion. Moreover, several mitochondrial ribosomal proteins appear to be lost. Conclusions: This study represents the first survey of mitochondrial gene expression of the linear multi-chromosomal mtDNA in box jellyfish (Cubozoa). Future exploration of small RNAs and the proteome of the mitochondrion will test the hypotheses presented herein.
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Redescription of Alatina alata (Reynaud, 1830) (Cnidaria: Cubozoa) from Bonaire, Dutch Caribbean
Zootaxa, 2013Co-Authors: Cheryl Lewis, Bastian Bentlage, Angel A Yanagihara, William Gillan, Johan Van Blerk, Daniel P. Keil, Alexandra E. Bely, Allen Gilbert CollinsAbstract:Here we establish a neotype for Alatina alata (Reynaud, 1830) from the Dutch Caribbean island of Bonaire. The species was originally described one hundred and eighty three years ago as Carybdea alata in La Centurie Zoologique—a monograph published by Rene Primevere Lesson during the age of worldwide scientific exploration. While monitoring monthly reproductive swarms of A. alata medusae in Bonaire, we documented the ecology and sexual reproduction of this Cubozoan species. Examination of forty six A. alata specimens and additional archived multimedia material in the collections of the National Museum of Natural History, Washington, DC revealed that A. alata is found at depths ranging from surface waters to 675 m. Additional studies have reported it at depths of up to 1607 m in the tropical and subtropical Atlantic Ocean. Herein, we resolve the taxonomic confusion long associated with A. alata due to a lack of detail in the original description and conflicting statements in the scientific literature. A new Cubozoan character, the velarial lappet, is described for this taxon. The complete description provided here serves to stabilize the taxonomy of the second oldest box jellyfish species, and provide a thorough redescription of the species.
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PHYLOGENETIC SYSTEMATICS, TAXONOMY, AND BIOGEOGRAPHY OF JELLYFISH (CNIDARIA: MEDUSOZOA)
2012Co-Authors: Bastian BentlageAbstract:The coastal shelf inhabiting box jellyfish (Cubozoa) represent the smallest class within Cnidaria with some 50 described species. A robust phylogenetic framework had been missing for Cubozoa. Herein, a molecular phylogeny for Cubozoa is presented. This phylogeny served as the basis for several taxonomic and nomenclatural changes in a reverse taxonomic approach, striving to align the classification scheme for Cubozoa with phylogenetic history. In addition, the revised classification led to a reevaluation of morphological characters used for the delineation and identification of species and higher taxa. This information was condensed into an illustrated taxonomic key to aid the identification of box jellyfish by non-specialists. Furthermore, the utility of ecological niche models for predicting the potential geographic distributions of box jellyfish based on correlations between species occurrences and environmental data was assessed. Since box jellyfish distributions are generally poorly documented, modeling approaches that make use of the limited data available may be of much value for making predictions about species distributions. Similarly, species distributions in the open oceans, in particular in the deep sea, are poorly understood and documented. A new approach to ecological niche and species distribution modeling in three dimensions was developed that has great potential for aiding studies of open ocean fauna. This new approach was used to derive an explicit a priori hypothesis about the population structure of a deep-sea inhabiting jellyfish species. In order to test this hypothesis and better understand the patterns of gene-flow in open ocean environments, population genomic data was used to evaluate population structure for this species on a global scale. The combined approach of ecological niche modeling and population genomics indicated that at least the species investigated here displays panmixia on a global scale.
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An illustrated key and synopsis of the families and genera of carybdeid box jellyfishes (Cnidaria: Cubozoa: Carybdeida), with emphasis on the “Irukandji family” (Carukiidae)
Journal of Natural History, 2012Co-Authors: Bastian Bentlage, Cheryl LewisAbstract:Box jellyfishes (Cnidaria: Cubozoa) have a profound impact on human activities because of their highly potent venoms that may lead to severe envenomations in humans. Cubozoa is one of the smallest classes within Cnidaria with only some 50 described species in seven families. The literature on Cubozoa is scattered and oftentimes difficult to access. In particular, comprehensive treatments of Cubozoa that present a comparative overview of the group are either non-existent or largely outdated. Here we provide a synopsis of the carybdeid Cubozoa (Carybdeida) including an illustrated key to the families and genera of this order. Of particular interest is the family Carukiidae, which contains the species that was originally attributed with causing a severe envenomation syndrome called Irukandji syndrome. One new species of Carukiidae, Malo filipina sp. nov., is described, Morbakka virulenta is redescribed and a neotype is designated, and an unidentified species of Morbakka is recorded from the Philippines.
Allen Gilbert Collins - One of the best experts on this subject based on the ideXlab platform.
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box stalked and upside down draft genomes from diverse jellyfish cnidaria acraspeda lineages alatina alata Cubozoa calvadosia cruxmelitensis staurozoa and cassiopea xamachana scyphozoa
GigaScience, 2019Co-Authors: Aki Ohdera, Cheryl Lewis Ames, Ehsan Kayal, Rebecca B Dikow, Marta Chiodin, Ben Busby, Stacy Pirro, Allen Gilbert CollinsAbstract:Background Anthozoa, Endocnidozoa, and Medusozoa are the 3 major clades of Cnidaria. Medusozoa is further divided into 4 clades, Hydrozoa, Staurozoa, Cubozoa, and Scyphozoa-the latter 3 lineages make up the clade Acraspeda. Acraspeda encompasses extraordinary diversity in terms of life history, numerous nuisance species, taxa with complex eyes rivaling other animals, and some of the most venomous organisms on the planet. Genomes have recently become available within Scyphozoa and Cubozoa, but there are currently no published genomes within Staurozoa and Cubozoa. Findings Here we present 3 new draft genomes of Calvadosia cruxmelitensis (Staurozoa), Alatina alata (Cubozoa), and Cassiopea xamachana (Scyphozoa) for which we provide a preliminary orthology analysis that includes an inventory of their respective venom-related genes. Additionally, we identify synteny between POU and Hox genes that had previously been reported in a hydrozoan, suggesting this linkage is highly conserved, possibly dating back to at least the last common ancestor of Medusozoa, yet likely independent of vertebrate POU-Hox linkages. Conclusions These draft genomes provide a valuable resource for studying the evolutionary history and biology of these extraordinary animals, and for identifying genomic features underlying venom, vision, and life history traits in Acraspeda.
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Redescription of Alatina alata (Reynaud, 1830) (Cnidaria: Cubozoa) from Bonaire, Dutch Caribbean
Zootaxa, 2013Co-Authors: Cheryl Lewis, Bastian Bentlage, Angel A Yanagihara, William Gillan, Johan Van Blerk, Daniel P. Keil, Alexandra E. Bely, Allen Gilbert CollinsAbstract:Here we establish a neotype for Alatina alata (Reynaud, 1830) from the Dutch Caribbean island of Bonaire. The species was originally described one hundred and eighty three years ago as Carybdea alata in La Centurie Zoologique—a monograph published by Rene Primevere Lesson during the age of worldwide scientific exploration. While monitoring monthly reproductive swarms of A. alata medusae in Bonaire, we documented the ecology and sexual reproduction of this Cubozoan species. Examination of forty six A. alata specimens and additional archived multimedia material in the collections of the National Museum of Natural History, Washington, DC revealed that A. alata is found at depths ranging from surface waters to 675 m. Additional studies have reported it at depths of up to 1607 m in the tropical and subtropical Atlantic Ocean. Herein, we resolve the taxonomic confusion long associated with A. alata due to a lack of detail in the original description and conflicting statements in the scientific literature. A new Cubozoan character, the velarial lappet, is described for this taxon. The complete description provided here serves to stabilize the taxonomy of the second oldest box jellyfish species, and provide a thorough redescription of the species.
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Cnidarian phylogenetic relationships as revealed by mitogenomics
BMC evolutionary biology, 2013Co-Authors: Ehsan Kayal, Allen Gilbert Collins, Béatrice Roure, Hervé Philippe, Dennis V. LavrovAbstract:Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) – cnidarians with a reproductive polyp and the absence of a medusa stage – and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) – cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria.
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Evolution of Linear Mitochondrial Genomes in Medusozoan Cnidarians
Genome biology and evolution, 2011Co-Authors: Ehsan Kayal, Bastian Bentlage, Stacy Pirro, Allen Gilbert Collins, Mohsen Kayal, Dennis V. LavrovAbstract:In nearly all animals, mitochondrial DNA (mtDNA) consists of a single circular molecule that encodes several subunits of the protein complexes involved in oxidative phosphorylation as well as part of the machinery for their expression. By contrast, mtDNA in species belonging to Medusozoa (one of the two major lineages in the phylum Cnidaria) comprises one to several linear molecules. Many questions remain on the ubiquity of linear mtDNA in medusozoans and the mechanisms responsible for its evolution, replication, and transcription. To address some of these questions, we determined the sequences of nearly complete linear mtDNA from 24 species representing all four medusozoan classes: Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. All newly determined medusozoan mitochondrial genomes harbor the 17 genes typical for cnidarians and map as linear molecules with a high degree of gene order conservation relative to the anthozoans. In addition, two open reading frames (ORFs), polB and ORF314, are identified in Cubozoan, schyphozoan, staurozoan, and trachyline hydrozoan mtDNA. polB belongs to the B-type DNA polymerase gene family, while the product of ORF314 may act as a terminal protein that binds telomeres. We posit that these two ORFs are remnants of a linear plasmid that invaded the mitochondrial genomes of the last common ancestor of Medusozoa and are responsible for its linearity. Hydroidolinan hydrozoans have lost the two ORFs and instead have duplicated cox1 at each end of their mitochondrial chromosome(s). Fragmentation of mtDNA occurred independently in Cubozoa and Hydridae (Hydrozoa, Hydroidolina). Our broad sampling allows us to reconstruct the evolutionary history of linear mtDNA in medusozoans.
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evolution of box jellyfish cnidaria Cubozoa a group of highly toxic invertebrates
Proceedings of The Royal Society B: Biological Sciences, 2010Co-Authors: Bastian Bentlage, Paulyn Cartwright, Angel A Yanagihara, Cheryl Lewis, Gemma S Richards, Allen Gilbert CollinsAbstract:Cubozoa (Cnidaria: Medusozoa) represents a small clade of approximately 50 described species, some of which cause serious human envenomations. Our understanding of the evolutionary history of Cubozoa has been limited by the lack of a sound phylogenetic hypothesis for the group. Here, we present a comprehensive Cubozoan phylogeny based on ribosomal genes coding for near-complete nuclear 18S (small subunit) and 28S (large subunit) and partial mitochondrial 16S. We discuss the implications of this phylogeny for our understanding of Cubozoan venom evolution, biogeography and life-history evolution. Our phylogenetic hypothesis suggests that: (i) the last common ancestor of Carybdeida probably possessed the mechanism(s) underlying Irukandji syndrome, (ii) deep divergences between Atlantic and Indo-Pacific clades may be explained by ancient vicariant events, and (iii) sexual dimorphism evolved a single time in concert with complex sexual behaviour. Furthermore, several Cubozoan taxa are either para- or polyphyletic, and we address some of these taxonomic issues by designating a new family, Carukiidae, a new genus, Copula, and by redefining the families Tamoyidae and Tripedaliidae. Lastly, Cubozoan species identities have long been misunderstood and the data presented here support many of the recent scientific descriptions of Cubozoan species. However, the results of a phylogeographic analysis of Alatina moseri from Hawai'i and Alatina mordens from Australia indicate that these two nominal species represent a single species that has maintained metapopulation cohesion by natural or anthropogenic dispersal.
Tsuyoshi Komiya - One of the best experts on this subject based on the ideXlab platform.
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Anatomy and affinities of a new 535‐million‐year‐old medusozoan from the Kuanchuanpu Formation, South China
Palaeontology, 2017Co-Authors: Xing Wang, Jian Han, Jean Vannier, Xiaoguang Yang, Kentaro Uesugi, Osamu Sasaki, Tsuyoshi KomiyaAbstract:We describe here Sinaster petalon gen. et sp. nov., a new embryonic form from the c. 535 million-year-old Kuanchuanpu Formation of South China (Ningqiang, Shaanxi Province). The excellent three-dimensional, phosphatic preservation of these microfossils allowed us to use x-ray microtomographic techniques to make accurate reconstructions of their internal structures and to compare their anatomy point-by-point with that of extant cnidarians and other animal groups. Sinaster petalon has anatomical features typical of extant Medusozoa (Cnidaria), such as coronal muscles, perradial and adradial frenula, interradial septa, accessory septa, gonad-lamellae, tentacle buds and perradial pockets. Although Sinaster cannot be straightforwardly assigned to any crown-group within Medusozoa, the presence of marginal lappets and endodermal lamellae suggests that it is closer to Cubozoa and Scyphozoa than to any other group of modern cnidarians. The tentative placement of Sinaster within the stem-group Cubozoa is justified by the presence of a velarium supported by a frenulum. The Cubozoan affinities of Sinaster are also supported by cladistic analysis.
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Anatomy and affinities of a new 535-million-year-old medusozoan from the Kuanchuanpu Formation, South China
Palaeontology, 2017Co-Authors: Xing Wang, Jian Han, Jean Vannier, Xiaoguang Yang, Kentaro Uesugi, Osamu Sasaki, Tsuyoshi KomiyaAbstract:We describe here Sinaster petalon gen. et sp. nov., a new embryonic form from the c. 535 million-year-old Kuanchuanpu Formation of South China (Ningqiang, Shaanxi Province). The excellent three-dimensional, phosphatic preservation of these microfossils allowed us to use x-ray microtomographic techniques to make accurate reconstructions of their internal structures and to compare their anatomy point-by-point with that of extant cnidarians and other animal groups. Sinaster petalon has anatomical features typical of extant Medusozoa (Cnidaria), such as coronal muscles, perradial and adradial frenula, interradial septa, accessory septa, gonad-lamellae, tentacle buds and perradial pockets. Although Sinaster cannot be straightforwardly assigned to any crown-group within Medusozoa, the presence of marginal lappets and endodermal lamellae suggests that it is closer to Cubozoa and Scyphozoa than to any other group of modern cnidarians. The tentative placement of Sinaster within the stem-group Cubozoa is justified by the presence of a velarium supported by a frenulum. The Cubozoan affinities of Sinaster are also supported by cladistic analysis.
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The basic morphology and internal anatomy of living cnidarians (anthozans, staurozoans, coronate scyphozoans, and Cubozoans, excepting hydrozoans).
2013Co-Authors: Jian Han, Xiaoguang Yang, Osamu Sasaki, Shin Kubota, Xiaoyong Yao, Degan Shu, Shunichi Kinoshita, Tsuyoshi KomiyaAbstract:(A) A fully grown individual of Morbakka virulenta (Kishinouyea, 1910) (Charybdeida, Cubozoa) from Japan, lateral view. (B) Rectangle area in (A), showing the blade-like pedalia, velarium, frenula, interradial septa and gonad-lamellae. (C–D) A juvenile individual of living Tripedalia cystophora Conant, 1897 (Charybdeida, Cubozoa) from Japan. (C) Oral view, showing the triangular apertural lappets, four pairs in the perradii and eight in the adradii; note the incipient pedalia. (D) Lateral view. (E) Diagrammatic horizontal section of Tripedalia cystophora, showing the internal anatomy, especially the gonad-lamellae and the suspensia, modified from ([17], Figure 23). (F) An oral view of a staurozoans. (G) Diagrammatic comparison of the gonads and gonad-lamellae in horizontal sections between a Cubozoan (lower part) and a staurozoan (upper part), modified from ([3], Figures 2–3). (H) Cross section of a coronate scyphozoan showing scalloped bell margin and internal gonads (simplified from Thiel,1966 [3]). (I) Cross section of an ideal hexanerous actiniarian through the pharynx (left) and below the pharynx (right), the numbers indicate the order of insertion of the new septa following the directive septa, modified from [2].
Cheryl Lewis - One of the best experts on this subject based on the ideXlab platform.
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Redescription of Alatina alata (Reynaud, 1830) (Cnidaria: Cubozoa) from Bonaire, Dutch Caribbean
Zootaxa, 2013Co-Authors: Cheryl Lewis, Bastian Bentlage, Angel A Yanagihara, William Gillan, Johan Van Blerk, Daniel P. Keil, Alexandra E. Bely, Allen Gilbert CollinsAbstract:Here we establish a neotype for Alatina alata (Reynaud, 1830) from the Dutch Caribbean island of Bonaire. The species was originally described one hundred and eighty three years ago as Carybdea alata in La Centurie Zoologique—a monograph published by Rene Primevere Lesson during the age of worldwide scientific exploration. While monitoring monthly reproductive swarms of A. alata medusae in Bonaire, we documented the ecology and sexual reproduction of this Cubozoan species. Examination of forty six A. alata specimens and additional archived multimedia material in the collections of the National Museum of Natural History, Washington, DC revealed that A. alata is found at depths ranging from surface waters to 675 m. Additional studies have reported it at depths of up to 1607 m in the tropical and subtropical Atlantic Ocean. Herein, we resolve the taxonomic confusion long associated with A. alata due to a lack of detail in the original description and conflicting statements in the scientific literature. A new Cubozoan character, the velarial lappet, is described for this taxon. The complete description provided here serves to stabilize the taxonomy of the second oldest box jellyfish species, and provide a thorough redescription of the species.
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An illustrated key and synopsis of the families and genera of carybdeid box jellyfishes (Cnidaria: Cubozoa: Carybdeida), with emphasis on the “Irukandji family” (Carukiidae)
Journal of Natural History, 2012Co-Authors: Bastian Bentlage, Cheryl LewisAbstract:Box jellyfishes (Cnidaria: Cubozoa) have a profound impact on human activities because of their highly potent venoms that may lead to severe envenomations in humans. Cubozoa is one of the smallest classes within Cnidaria with only some 50 described species in seven families. The literature on Cubozoa is scattered and oftentimes difficult to access. In particular, comprehensive treatments of Cubozoa that present a comparative overview of the group are either non-existent or largely outdated. Here we provide a synopsis of the carybdeid Cubozoa (Carybdeida) including an illustrated key to the families and genera of this order. Of particular interest is the family Carukiidae, which contains the species that was originally attributed with causing a severe envenomation syndrome called Irukandji syndrome. One new species of Carukiidae, Malo filipina sp. nov., is described, Morbakka virulenta is redescribed and a neotype is designated, and an unidentified species of Morbakka is recorded from the Philippines.
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evolution of box jellyfish cnidaria Cubozoa a group of highly toxic invertebrates
Proceedings of The Royal Society B: Biological Sciences, 2010Co-Authors: Bastian Bentlage, Paulyn Cartwright, Angel A Yanagihara, Cheryl Lewis, Gemma S Richards, Allen Gilbert CollinsAbstract:Cubozoa (Cnidaria: Medusozoa) represents a small clade of approximately 50 described species, some of which cause serious human envenomations. Our understanding of the evolutionary history of Cubozoa has been limited by the lack of a sound phylogenetic hypothesis for the group. Here, we present a comprehensive Cubozoan phylogeny based on ribosomal genes coding for near-complete nuclear 18S (small subunit) and 28S (large subunit) and partial mitochondrial 16S. We discuss the implications of this phylogeny for our understanding of Cubozoan venom evolution, biogeography and life-history evolution. Our phylogenetic hypothesis suggests that: (i) the last common ancestor of Carybdeida probably possessed the mechanism(s) underlying Irukandji syndrome, (ii) deep divergences between Atlantic and Indo-Pacific clades may be explained by ancient vicariant events, and (iii) sexual dimorphism evolved a single time in concert with complex sexual behaviour. Furthermore, several Cubozoan taxa are either para- or polyphyletic, and we address some of these taxonomic issues by designating a new family, Carukiidae, a new genus, Copula, and by redefining the families Tamoyidae and Tripedaliidae. Lastly, Cubozoan species identities have long been misunderstood and the data presented here support many of the recent scientific descriptions of Cubozoan species. However, the results of a phylogeographic analysis of Alatina moseri from Hawai'i and Alatina mordens from Australia indicate that these two nominal species represent a single species that has maintained metapopulation cohesion by natural or anthropogenic dispersal.
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Clarifying the identity of the Japanese Habu-kurage, Chironex yamaguchii, sp. nov. (Cnidaria: Cubozoa: Chirodropida)
Zootaxa, 2009Co-Authors: Cheryl Lewis, Bastian BentlageAbstract:Here we describe the new species Chironex yamaguchii (Cnidaria: Cubozoa) from the Ryukyu Archipelago, Japan. This highly venomous cubomedusa, commonly referred to as Habu-kurage in Japan, is the culprit for several fatalities in Japanese waters. The scientific name adopted for this species in the literature is Chiropsalmus quadrigatus, but our taxonomic investigations show that this represents a case of mistaken identity. In fact, Habu-kurage is a close relative of Chironex fleckeri, which is particularly interesting because the latter has a reputation for being the most venomous animal known. Differences in the shape of the pedalial canal bend, the number of tentacles, and bell size distinguish the two species. In addition to Japan, Chironex yamaguchii is widely distributed in the Philippines.
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Courtship and reproduction in Carybdea sivickisi (Cnidaria : Cubozoa)
Marine Biology, 2005Co-Authors: Cheryl Lewis, Tristan A. F. LongAbstract:Courtship and fertilization events in Cubozoans have received little attention from biologists, and much of what we know about these processes is based on conjecture or scant anecdotal evidence. I set out to describe these processes in the Cubozoan Carybdea sivickisi by observing mature medusae in vitro. Mature adults engage in courtship during which spermatophores are transferred from the male to the female, who then inserts the gametes into her manubrium. Females accepted multiple spermatophores from multiple males, and only produced one embryo strand. This study also provides evidence that the presence of conspicuous velar spots on the female’s bell margin is a signal of sexual maturity, and that sexual maturity was not reached in either sex until individuals had a bell diameter of at least 5 mm.
Ehsan Kayal - One of the best experts on this subject based on the ideXlab platform.
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box stalked and upside down draft genomes from diverse jellyfish cnidaria acraspeda lineages alatina alata Cubozoa calvadosia cruxmelitensis staurozoa and cassiopea xamachana scyphozoa
GigaScience, 2019Co-Authors: Aki Ohdera, Cheryl Lewis Ames, Ehsan Kayal, Rebecca B Dikow, Marta Chiodin, Ben Busby, Stacy Pirro, Allen Gilbert CollinsAbstract:Background Anthozoa, Endocnidozoa, and Medusozoa are the 3 major clades of Cnidaria. Medusozoa is further divided into 4 clades, Hydrozoa, Staurozoa, Cubozoa, and Scyphozoa-the latter 3 lineages make up the clade Acraspeda. Acraspeda encompasses extraordinary diversity in terms of life history, numerous nuisance species, taxa with complex eyes rivaling other animals, and some of the most venomous organisms on the planet. Genomes have recently become available within Scyphozoa and Cubozoa, but there are currently no published genomes within Staurozoa and Cubozoa. Findings Here we present 3 new draft genomes of Calvadosia cruxmelitensis (Staurozoa), Alatina alata (Cubozoa), and Cassiopea xamachana (Scyphozoa) for which we provide a preliminary orthology analysis that includes an inventory of their respective venom-related genes. Additionally, we identify synteny between POU and Hox genes that had previously been reported in a hydrozoan, suggesting this linkage is highly conserved, possibly dating back to at least the last common ancestor of Medusozoa, yet likely independent of vertebrate POU-Hox linkages. Conclusions These draft genomes provide a valuable resource for studying the evolutionary history and biology of these extraordinary animals, and for identifying genomic features underlying venom, vision, and life history traits in Acraspeda.
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Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa)
2016Co-Authors: Ehsan Kayal, Bastian Bentlage, Allen G. CollinsAbstract:Background: In most animals, the mitochondrial genome is characterized by its small size, organization into a single circular molecule, and a relative conservation of the number of encoded genes. In box jellyfish (Cubozoa, Cnidaria), the mitochondrial genome is organized into 8 linear mito-chromosomes harboring between one and 4 genes each, including 2 extra protein-coding genes: mt-polB and orf314. Such an organization challenges the traditional view of mitochondrial DNA (mtDNA) expression in animals. In this study, we investigate the pattern of mitochondrial gene expression in the box jellyfish Alatina alata, as well as several key nuclear-encoded molecular pathways involved in the processing of mitochondrial gene transcription. Results: Read coverage of DNA-seq data is relatively uniform for all 8 mito-chromosomes, suggesting that each mito-chromosome is present in equimolar proportion in the mitochondrion. Comparison of DNA and RNA-seq based assemblies indicates that mito-chromosomes are transcribed into individual transcripts in which the beginning and ending are highly conserved. Expression levels for mt-polB and orf314 are similar to those of other mitochondrial-encoded genes, which provides further evidence for them having functional roles in the mitochondrion. Survey of the transcriptome suggests recognition of the mitochondrial tRNA-Met by the cytoplasmic aminoacyl-tRNA synthetase counterpart and C-to-U editing of the cytoplasmic tRNA-Trp after import into the mitochondrion. Moreover, several mitochondrial ribosomal proteins appear to be lost. Conclusions: This study represents the first survey of mitochondrial gene expression of the linear multi-chromosomal mtDNA in box jellyfish (Cubozoa). Future exploration of small RNAs and the proteome of the mitochondrion will test the hypotheses presented herein.
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Cnidarian phylogenetic relationships as revealed by mitogenomics
BMC evolutionary biology, 2013Co-Authors: Ehsan Kayal, Allen Gilbert Collins, Béatrice Roure, Hervé Philippe, Dennis V. LavrovAbstract:Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) – cnidarians with a reproductive polyp and the absence of a medusa stage – and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) – cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria.
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Evolution of Linear Mitochondrial Genomes in Medusozoan Cnidarians
Genome biology and evolution, 2011Co-Authors: Ehsan Kayal, Bastian Bentlage, Stacy Pirro, Allen Gilbert Collins, Mohsen Kayal, Dennis V. LavrovAbstract:In nearly all animals, mitochondrial DNA (mtDNA) consists of a single circular molecule that encodes several subunits of the protein complexes involved in oxidative phosphorylation as well as part of the machinery for their expression. By contrast, mtDNA in species belonging to Medusozoa (one of the two major lineages in the phylum Cnidaria) comprises one to several linear molecules. Many questions remain on the ubiquity of linear mtDNA in medusozoans and the mechanisms responsible for its evolution, replication, and transcription. To address some of these questions, we determined the sequences of nearly complete linear mtDNA from 24 species representing all four medusozoan classes: Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. All newly determined medusozoan mitochondrial genomes harbor the 17 genes typical for cnidarians and map as linear molecules with a high degree of gene order conservation relative to the anthozoans. In addition, two open reading frames (ORFs), polB and ORF314, are identified in Cubozoan, schyphozoan, staurozoan, and trachyline hydrozoan mtDNA. polB belongs to the B-type DNA polymerase gene family, while the product of ORF314 may act as a terminal protein that binds telomeres. We posit that these two ORFs are remnants of a linear plasmid that invaded the mitochondrial genomes of the last common ancestor of Medusozoa and are responsible for its linearity. Hydroidolinan hydrozoans have lost the two ORFs and instead have duplicated cox1 at each end of their mitochondrial chromosome(s). Fragmentation of mtDNA occurred independently in Cubozoa and Hydridae (Hydrozoa, Hydroidolina). Our broad sampling allows us to reconstruct the evolutionary history of linear mtDNA in medusozoans.