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Schuchert Peter - One of the best experts on this subject based on the ideXlab platform.
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Aligned and trimmed 16S and COI DNA sequences of Oceaniidae (Hydrozoa)
2018Co-Authors: Schuchert PeterAbstract:Aligned and trimmed 16S and COI sequences of Oceaniidae (Hydrozoa) used for the study "The polyps of Oceania armata identified by DNA barcoding (Cnidaria, Hydrozoa)" Format is Fasta, files are text files
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Specimen photos of DNA sample MHNG-Hydrozoa-DNA1161
2018Co-Authors: Schuchert PeterAbstract:Specimen photos of DNA sample MHNG-Hydrozoa-DNA1161 Sample data collection locality: Norway, Korsfjord GPS: 60.1846°N 5.196°E collection date: 14.06.2016 depth: 0-600m gear: vertical plankton tow number of individuals or colonies: 3 preservation: 95 % ethanol figured specimen used for DNA extraction: yes part used for DNA extraction: whole animal DNA extraction: 10.5281/zenodo.57067 voucher specimen deposited: MHNG-INVE-94100 (other specimen than used for DNA extraction) Taxonomy Phylum: Cnidaria Class: Hydrozoa Family: Melicertidae Species: Melicertum octocostatum (M. Sars, 1835) life stage: medusa identified by: P. Schuchert size: 6-9 mm diameter
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Specimen photos of DNA sample MHNG Hydrozoa DNA920 and DNA1169
2018Co-Authors: Schuchert PeterAbstract:Document type: Photos of specimen used for DNA extraction Author: Peter Schuchert Muséum d'histoire naturelle route de Malagnou 1 1208 Genève Switzerland DNA sample numbers: Hydrozoa DNA920 and DNA1169 Phylum: Cnidaria Class: Hydrozoa Family: Campanulariidae Species: Clytia gregaria (L. Agassiz, 1862) life stage: medusa identified by: P. Schuchert size: 20-25 mm diameter collection locality: USA, WA, Friday Harbor floating docks GPS: 48.5451 -123.0121 collection date: 23.05.2011 depth: 0-0.5 m gear: dip beaker number of individuals or colonies: >3 preservation: 95 % ethanol figured specimen used for DNA extraction: in part part used for DNA extraction: whole medusa DNA extraction: voucher specimen deposited: no comments: many identical medusae, two used for DNA extractions, it is unknown if the illustrated individual is one used for the DNA extraction
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Specimen photos of DNA sample MHNG-Hydrozoa-DNA1110
2018Co-Authors: Schuchert PeterAbstract:DNA sample number: Hydrozoa DNA1110 Phylum: Cnidaria Class: Hydrozoa Family: Eirenidae Species: Eutonina indicans (Romanes, 1876) life stage: medusa identified by: P. Schuchert size: 26 mm diameter collection locality: Norway, Fanafjord, Kinnar Osen GPS: 60.2473 5.2268 collection date: 21.04.2015 depth: 0-20 gear: plankton net 300 µm number of individuals or colonies: >10 preservation: 95 % ethanol figured specimen used for DNA extraction: no ? yes for RNA part used for DNA extraction: part DNA extraction: 3.06.2015 voucher specimen deposited: no comments: numerous identical specimens collected, 16S KY363946 Used in: Schuchert P., Hosia A., Leclère L. 2017. Identification of the polyp stage of three leptomedusa species using DNA barcoding. Revue suisse de Zoologie 124(1): 167-182. https://dx.doi.org/10.5281/zenodo.322675
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Specimen photos of DNA sample MHNG Hydrozoa DNA1145
2018Co-Authors: Schuchert PeterAbstract:Specimen photos of DNA sample MHNG Hydrozoa DNA1145 medusa of Oceania armata collected in the Bay of Villefranche-sur-mer, France
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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Phylogenetic analysis of higher-level relationships within Hydroidolina (Cnidaria: Hydrozoa) using mitochondrial genome data and insight into their mitochondrial transcription
PeerJ, 2015Co-Authors: Ehsan Kayal, Bastian Bentlage, Paulyn Cartwright, Angel A. Yanagihara, Dhugal J. Lindsay, Russell R. Hopcroft, Allen Gilbert CollinsAbstract:Hydrozoans display the most morphological diversity within the phylum Cnidaria. While recent molecular studies have provided some insights into their evolutionary history, sister group relationships remain mostly unresolved, particularly at mid-taxonomic levels. Specifically, within Hydroidolina, the most speciose Hydrozoan subclass, the relationships and sometimes integrity of orders are highly unsettled. Here we obtained the near complete mitochondrial sequence of twenty-six hydroidolinan Hydrozoan species from a range of sources (DNA and RNA-seq data, long-range PCR). Our analyses confirm previous inference of the evolution of mtDNA in Hydrozoa while introducing a novel genome organization. Using RNA-seq data, we propose a mechanism for the expression of mitochondrial mRNA in Hydroidolina that can be extrapolated to the other medusozoan taxa. Phylogenetic analyses using the full set of mitochondrial gene sequences provide some insights into the order-level relationships within Hydroidolina, including siphonophores as the first diverging clade, a well-supported clade comprised of Leptothecata-Filifera III-IV, and a second clade comprised of Aplanulata-Capitata s.s.-Filifera I-II. Finally, we describe our relatively inexpensive and accessible multiplexing strategy to sequence long-range PCR amplicons that can be adapted to most high-throughput sequencing platforms.
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Evolution of Linear Mitochondrial Genomes in Medusozoan Cnidarians
Genome biology and evolution, 2011Co-Authors: Ehsan Kayal, Allen Gilbert Collins, Bastian Bentlage, Stacy Pirro, 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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Cladistic analysis of Medusozoa and cnidarian evolution
Invertebrate Biology, 2005Co-Authors: Allen Gilbert CollinsAbstract:Abstract. A cladistic analysis of 87 morphological and life history characters of medusozoan cnidarians, rooted with Anthozoa, results in the phylogenetic hypothesis (Anthozoa (Hydrozoa (Scyphozoa (Staurozoa, Cubozoa)))). Staurozoa is a new class of Cnidaria consisting of Stauromedusae and the fossil group Conulatae. Scyphozoa is redefined as including those medusozoans characterized by strobilation and ephyrae (Coronatae, Semaeostomeae, and Rhizostomeae). Within Hydrozoa, Limnomedusae is identified as either the earliest diverging Hydrozoan lineage or as the basal group of either Trachylina (Actinulida (Trachymedusae (Narcomedusae, Laingiomedusae))) or Hydroidolina (Leptothecata (Siphonophorae, Anthoathecata)). Cladistic results are highly congruent with recently published phylogenetic analyses based on 18S molecular characters. We propose a phylogenetic classification of Medusozoa that is consistent with phylogenetic hypotheses based on our cladistic results, as well as those derived from 18S analyses. Optimization of the characters presented in this analysis are used to discuss evolutionary scenarios. The ancestral cnidarian probably had a sessile biradial polyp as an adult form. The medusa is inferred to be a synapomorphy of Medusozoa. However, the ancestral process (metamorphosis of the apical region of the polyp or lateral budding involving an entocodon) could not be inferred unequivocally. Similarly, character states for sense organs and nervous systems could not be inferred for the ancestral medusoid of Medusozoa.
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Phylogeny of Medusozoa and the evolution of cnidarian life cycles
Journal of Evolutionary Biology, 2002Co-Authors: Allen Gilbert CollinsAbstract:Cubozoa; development; Hydrozoa; Scyphozoa; Stauromedusae. Abstract To investigate the evolution of cnidarian life cycles, data from the small subunit of the ribosome are used to derive a phylogenetic hypothesis for Medusozoa. These data indicate that Cnidaria is monophyletic and composed of Anthozoa and Medusozoa. While Cubozoa and Hydrozoa are well supported clades, Scyphozoa appears to be paraphyletic. Stauromedusae is possibly the sister group of either Cubozoa or all other medusozoans. The phylogenetic results suggest that: the polyp probably preceded the medusa in the evolution of Cnidaria; within Hydrozoa, medusa development involving the entocodon is ancestral; within Trachylina, the polyp was lost and subsequently regained in the parasitic narcomedusans; within Siphonophorae, the float originated prior to swimming bells; stauromedusans are not likely to be descended from ancestors that produced medusae by strobilation; and cubozoan polyps are simplified from those of their ancestors, which possessed polyps with gastric septa and four mesogleal muscle bands and peristomial pits.
Ferdinando Boero - One of the best experts on this subject based on the ideXlab platform.
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Missing species among Mediterranean non-Siphonophoran Hydrozoa
Biodiversity and Conservation, 2015Co-Authors: Cinzia Gravili, Stanislao Bevilacqua, Antonio Terlizzi, Ferdinando BoeroAbstract:Hydrozoa of the Mediterranean Sea are well known and a recent monograph covers 457 species. Mediterranean non-Siphonophoran Hydrozoa comprises 398 species, an increasing number due to continuous updates, representing about 10 % of the 3,702 currently valid species reported in a recent world assessment of Hydrozoan diversity. Many new records are non indigenous species, previously described species that occurred elsewhere and whose arrival was presumably caused by human activities. However, many species reported in the past are not recorded in recent times. Realistic assessments of species pools require addition of new species, but also subtraction of species not found since a certain period. With the confidence of extinction index, cases of putative extinction can be raised. Out of the 398 known species, only 162 (41 %) have been reported in the last decade, while 53 (13 %) are not recorded in the literature since at least 41 years. According to the confidence of extinction index, 60 % of the 53 missing species are extinct, and 11 % are putatively extinct from the basin. From a biogeographical point of view, the missing species are: 34 % endemic, 19 % boreal, 15 % Mediterranean-Atlantic, 11 % Indo-Pacific, 11 % circumtropical, 4 % cosmopolitan, 2 % tropical-Atlantic, 4 % non-classifiable. Fluctuations in species composition into a certain area cause heavy variability in the expression of both structural and functional biodiversity. As consequence, the regional biodiversity should be analyzed through its temporal evolution, to detect changes and their possible causes. This approach has profound consequences on biodiversity assessments and also on the compilation of red lists.
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The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide.
Zootaxa, 2015Co-Authors: Cinzia Gravili, Cristina Gioia Di Camillo, Stefano Piraino, Luis Martell, Doris De Vito, Ferdinando BoeroAbstract:The majority of Hydrozoa is represented by not readily noticeable, small species. In recent decades, however, taxonomic knowledge of the group has increased worldwide, with a significant number of investigations focused on the Mediterranean Sea. Over more than two decades, 115 species of Hydrozoans were recorded from coastal waters along nearly 300 km of the Salento Peninsula (Apulia, Italy). For each species, records from different collections were merged into single sheets of a general database. For each species, the following information is reported: description, cnidome, biology, occurrence in Salento, worldwide distribution, and bibliography. Descriptions refer to the benthic hydroid stage and, when present, also to the planktonic medusa stage. The 115 species of Hydrozoa, recorded along the Salento coastline, represent 25% of the Mediterranean Hydrozoa fauna (totaling 461 species), and nearly 3% of 3,702 world's known species covered in a recent monograph. Four species are non-indigenous, three of them with invasive behavior (Clytia hummelincki, Clytia linearis, and Eudendrium carneum), and one species now very common (Eudendrium merulum) in Salento. The complete life cycle of Clytia paulensis (Vanhoffen, 1910) is described for the first time.
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Association between luminous bacteria and Hydrozoa in the northern Ionian Sea
Journal of the Marine Biological Association of the United Kingdom, 2011Co-Authors: Cinzia Gravili, Ferdinando Boero, P. Alifano, L. StabiliAbstract:Several hydroid species live associated with many organisms, including bacteria. Hydroid–bacteria associations were searched for in twenty Hydrozoa species that were collected in the northern Ionian Sea and observed under blue light excitation. Of these, six showed high fluorescence on the outer perisarc, five appeared medium fluorescent, four were slightly fluorescent, and five did not show any fluorescence. Luminous bacteria were isolated and counted from the surface of the fluorescent hydroids. Their association with Hydrozoan species could be explained by their feeding activity on the chitinous structures of the perisarc, as previous research on the hydroid Aglaophenia octodonta showed. Moreover, microalgae were always recovered together with luminous bacteria in the strongly, medium and slightly fluorescent hydroids. Further studies will be undertaken to characterize the luminous bacteria isolated from the surface of the examined Hydrozoans as well as to better understand whether their interaction with hydroids is only related to chitin utilization or if their coexistence with microalgae in Hydrozoans has an ecological meaning.
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Symbiotic relationships between hydroids and bryozoans.
Symbiosis, 2007Co-Authors: Stefania Puce, Giorgio Bavestrello, Cristina Gioia Di Camillo, Ferdinando BoeroAbstract:Hydroids have established several symbiotic relationships with bryozoans. The association with Bryozoa probably evolved independently within the Hydrozoa. In fact, three unrelated hydroid families, Lovenellidae, Cytaeididae and Pandeidae, have only one species each that is symbiotic with bryozoans, whereas the Zancleidae probably went through a wide radiation leading to specialized associations with the Bryozoa. The symbiosis with Hydrozoa is recorded in few bryozoan families: almost all zancleids are associated with species of the families Schizoporellidae, Phidoloporinidae and Lepraliellidae. Other families, extremely common both in tropical and temperate waters were never recorded in association with hydroids. The association between hydroids and bryozoans seems to require a high degree of specialization resulting in peculiar trophic strategies ranging from commensalism to parasitism and in morphological modifications as tentacle reduction and hydrorhiza covering by the bryozoan skeleton.
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phylogenetic analysis with multiple markers indicates repeated loss of the adult medusa stage in campanulariidae Hydrozoa cnidaria
Molecular Phylogenetics and Evolution, 2006Co-Authors: Annette F. Govindarajan, Ferdinando Boero, Kenneth M HalanychAbstract:The Campanulariidae is a group of leptomedusan hydroids (Hydrozoa, Cnidaria) that exhibit a diverse array of life cycles ranging from species with a free medusa stage to those with a reduced or absent medusa stage. Perhaps the best-known member of the taxon is Obelia which is often used as a textbook model of Hydrozoan life history. However, Obelia medusae have several unique features leading to a hypothesis that Obelia arose, in a saltational fashion, from an ancestor that lacked a medusa, possibly representing an example of a rare evolutionary reversal. To address the evolution of adult sexual stages in Campanulariidae, a molecular phylogenetic approach was employed using two nuclear (18S rDNA and calmodulin) and two mitochondrial (16S rDNA and cytochrome c oxidase subunit I) genes. Prior to the main analysis, we conducted a preliminary analysis of leptomedusan taxa which suggests that Campanulariidae as presently considered needs to be redeWned. Campanulariid analyses are consistent with morphological understanding in that three major clades are recovered. However, several recognized genera are not monophyletic calling into question some “diagnostic” features. Furthermore, ancestral states were reconstructed using parsimony, and a sensitivity analysis was conducted to investigate possible evolutionary transitions in life-history stages. The results indicate that life-cycle transitions have occurred multiple times, and that Obelia might be derived from an ancestor with Clytia-like features. 2005 Elsevier Inc. All rights reserved.
Paulyn Cartwright - One of the best experts on this subject based on the ideXlab platform.
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Frizzled3 expression and colony development in hydractiniid Hydrozoans.
Journal of experimental zoology. Part B Molecular and developmental evolution, 2020Co-Authors: Steven M. Sanders, Matthew K. Travert, Paulyn CartwrightAbstract:Hydractiniid Hydrozoan colonies are comprised of individual polyps connected by tube-like stolons or a sheet-like mat. Mat and stolons function to integrate the colony through continuous epithelia and shared gastrovascular cavity. Although mechanisms of Hydrozoan polyp development have been well studied, little is known about the signaling processes governing the patterning of colonies. Here we investigate the Wnt receptor family Frizzled. Phylogenetic analysis reveals that Hydrozoans possess four Frizzled orthologs. We find that one of these genes, Frizzled3, shows a spatially restricted expression pattern in colony-specific tissue in two hydractiniid Hydrozoans, Hydractinia symbiolongicarpus and Podocoryna carnea, in a manner that corresponds to their distinct colony forms (stolonal mat in Hydractinia and free stolons in Podocoryna). Interestingly, Frizzled3 was lost in the genome of Hydra, which is a solitary polyp and thus lacks colony-specific tissue. Current evidence suggests that the Wnt signaling pathway plays a key role in the evolution of colony diversity and colony loss in Hydrozoa.
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Phylogenetic analysis of higher-level relationships within Hydroidolina (Cnidaria: Hydrozoa) using mitochondrial genome data and insight into their mitochondrial transcription
PeerJ, 2015Co-Authors: Ehsan Kayal, Bastian Bentlage, Paulyn Cartwright, Angel A. Yanagihara, Dhugal J. Lindsay, Russell R. Hopcroft, Allen Gilbert CollinsAbstract:Hydrozoans display the most morphological diversity within the phylum Cnidaria. While recent molecular studies have provided some insights into their evolutionary history, sister group relationships remain mostly unresolved, particularly at mid-taxonomic levels. Specifically, within Hydroidolina, the most speciose Hydrozoan subclass, the relationships and sometimes integrity of orders are highly unsettled. Here we obtained the near complete mitochondrial sequence of twenty-six hydroidolinan Hydrozoan species from a range of sources (DNA and RNA-seq data, long-range PCR). Our analyses confirm previous inference of the evolution of mtDNA in Hydrozoa while introducing a novel genome organization. Using RNA-seq data, we propose a mechanism for the expression of mitochondrial mRNA in Hydroidolina that can be extrapolated to the other medusozoan taxa. Phylogenetic analyses using the full set of mitochondrial gene sequences provide some insights into the order-level relationships within Hydroidolina, including siphonophores as the first diverging clade, a well-supported clade comprised of Leptothecata-Filifera III-IV, and a second clade comprised of Aplanulata-Capitata s.s.-Filifera I-II. Finally, we describe our relatively inexpensive and accessible multiplexing strategy to sequence long-range PCR amplicons that can be adapted to most high-throughput sequencing platforms.
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Character Evolution in Hydrozoa (phylum Cnidaria)
Integrative and comparative biology, 2010Co-Authors: Paulyn Cartwright, Annalise M. NawrockiAbstract:The diversity of Hydrozoan life cycles, as manifested in the wide range of polyp, colony, and medusa morphologies, has been appreciated for centuries. Unraveling the complex history of characters involved in this diversity is critical for understanding the processes driving Hydrozoan evolution. In this study, we use a phylogenetic approach to investigate the evolution of morphological characters in Hydrozoa. A molecular phylogeny is reconstructed using ribosomal DNA sequence data. Several characters involving polyp, colony, and medusa morphology are coded in the terminal taxa. These characters are mapped onto the phylogeny and then the ancestral character states are reconstructed. This study confirms the complex evolutionary history of Hydrozoan morphological characters. Many of the characters involving polyp, colony, and medusa morphology appear as synapomorphies for major Hydrozoan clades, yet homoplasy is commonplace.
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Expression of a Gsx parahox gene, Cnox-2, in colony ontogeny in Hydractinia (Cnidaria: Hydrozoa).
Journal of experimental zoology. Part B Molecular and developmental evolution, 2006Co-Authors: Paulyn Cartwright, Bernd Schierwater, Leo W. BussAbstract:The ontogeny of colonial animals is markedly distinct from that of solitary animals, yet no regulatory genes have thus far been implicated in colonial development. In cnidarians, colony ontogeny is characterized by the production of a nexus of vascular stolons, from which the feeding and reproductive structures, called polyps, are budded. Here we describe and characterize the Gsx parahox gene, Cnox-2, in the colonial cnidarian Hydractinia symbiolongicarpus of the class Hydrozoa. Cnox-2 is expressed in prominent components of the colony-wide patterning system; in the epithelia of distal stolon tips and polyp bud rudiments. Both are regions of active morphogenetic activity, characterized by cytologically and behaviorally distinct epithelia. Experimental induction and elimination of stolonal tips result in up- and down-regulation, respectively, of Cnox-2 expression. In the developing polyp, Cnox-2 expression remains uniformly high throughout the period of axial differentiation. The differential oral-aboral Cnox-2 expression in the epithelia of the mature polyp, previously described for this and another Hydrozoan, arises after oral structures have completed development. Differential Cnox-2 expression is, thus, associated with key aspects of patterning of both the colony and the polyp, a finding that is particularly striking given that polyp and colony form are dissociable in the evolution of Hydrozoa.
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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Phylogenetic analysis of higher-level relationships within Hydroidolina (Cnidaria: Hydrozoa) using mitochondrial genome data and insight into their mitochondrial transcription
PeerJ, 2015Co-Authors: Ehsan Kayal, Bastian Bentlage, Paulyn Cartwright, Angel A. Yanagihara, Dhugal J. Lindsay, Russell R. Hopcroft, Allen Gilbert CollinsAbstract:Hydrozoans display the most morphological diversity within the phylum Cnidaria. While recent molecular studies have provided some insights into their evolutionary history, sister group relationships remain mostly unresolved, particularly at mid-taxonomic levels. Specifically, within Hydroidolina, the most speciose Hydrozoan subclass, the relationships and sometimes integrity of orders are highly unsettled. Here we obtained the near complete mitochondrial sequence of twenty-six hydroidolinan Hydrozoan species from a range of sources (DNA and RNA-seq data, long-range PCR). Our analyses confirm previous inference of the evolution of mtDNA in Hydrozoa while introducing a novel genome organization. Using RNA-seq data, we propose a mechanism for the expression of mitochondrial mRNA in Hydroidolina that can be extrapolated to the other medusozoan taxa. Phylogenetic analyses using the full set of mitochondrial gene sequences provide some insights into the order-level relationships within Hydroidolina, including siphonophores as the first diverging clade, a well-supported clade comprised of Leptothecata-Filifera III-IV, and a second clade comprised of Aplanulata-Capitata s.s.-Filifera I-II. Finally, we describe our relatively inexpensive and accessible multiplexing strategy to sequence long-range PCR amplicons that can be adapted to most high-throughput sequencing platforms.
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Evolution of Linear Mitochondrial Genomes in Medusozoan Cnidarians
Genome biology and evolution, 2011Co-Authors: Ehsan Kayal, Allen Gilbert Collins, Bastian Bentlage, Stacy Pirro, 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.
