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Heuchel A, Emblem Å, Jørgensen TE, Moum T, Johansen SD. The Mitogenome of the Subarctic Octocoral Alcyonium digitatum Reveals a Putative tRNA Pro Gene Nested within MutS. Curr Issues Mol Biol 2024; 46:8104-8110. [PMID: 39194696 DOI: 10.3390/cimb46080479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/24/2024] [Accepted: 07/25/2024] [Indexed: 08/29/2024] Open
Abstract
We sequenced and analyzed the complete mitogenome of a Norwegian isolate of the octocoral Alcyonium digitatum using the Ion Torrent sequencing technology. The 18,790 bp circular mitochondrial genome was found to harbor the same set of 17 genes, which encode 14 protein subunits, two structural ribosomal RNAs and one tRNA, as reported in other octocorals. In addition, we detected a new tRNAPro-like gene sequence nested within the MutS protein coding region. This putative tRNA gene feature appears to be conserved among the octocorals but has not been reported previously. The A. digitatum mitogenome was also shown to harbor an optional gene (ORFA) that encodes a putative protein of 191 amino acids with unknown function. A mitogenome-based phylogenetic analysis, presented as a maximum likelihood tree, showed that A. digitatum clustered with high statistical confidence with two other Alcyonium species endemic to the Mediterranean Sea and the Southeast Pacific Ocean.
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Affiliation(s)
- Alisa Heuchel
- Genomic Division, Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway
- Abisko Scientific Research Station, Swedish Polar Research Secretariat, SE-981 07 Abisko, Sweden
| | - Åse Emblem
- Research Laboratory, Nordland Hospital Trust, 8005 Bodø, Norway
| | - Tor Erik Jørgensen
- Genomic Division, Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway
| | - Truls Moum
- Genomic Division, Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway
| | - Steinar Daae Johansen
- Genomic Division, Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway
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2
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Quattrini AM, Snyder KE, Purow-Ruderman R, Seiblitz IGL, Hoang J, Floerke N, Ramos NI, Wirshing HH, Rodriguez E, McFadden CS. Mito-nuclear discordance within Anthozoa, with notes on unique properties of their mitochondrial genomes. Sci Rep 2023; 13:7443. [PMID: 37156831 PMCID: PMC10167242 DOI: 10.1038/s41598-023-34059-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 04/24/2023] [Indexed: 05/10/2023] Open
Abstract
Whole mitochondrial genomes are often used in phylogenetic reconstruction. However, discordant patterns in species relationships between mitochondrial and nuclear phylogenies are commonly observed. Within Anthozoa (Phylum Cnidaria), mitochondrial (mt)-nuclear discordance has not yet been examined using a large and comparable dataset. Here, we used data obtained from target-capture enrichment sequencing to assemble and annotate mt genomes and reconstruct phylogenies for comparisons to phylogenies inferred from hundreds of nuclear loci obtained from the same samples. The datasets comprised 108 hexacorals and 94 octocorals representing all orders and > 50% of extant families. Results indicated rampant discordance between datasets at every taxonomic level. This discordance is not attributable to substitution saturation, but rather likely caused by introgressive hybridization and unique properties of mt genomes, including slow rates of evolution driven by strong purifying selection and substitution rate variation. Strong purifying selection across the mt genomes caution their use in analyses that rely on assumptions of neutrality. Furthermore, unique properties of the mt genomes were noted, including genome rearrangements and the presence of nad5 introns. Specifically, we note the presence of the homing endonuclease in ceriantharians. This large dataset of mitochondrial genomes further demonstrates the utility of off-target reads generated from target-capture data for mt genome assembly and adds to the growing knowledge of anthozoan evolution.
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Affiliation(s)
- Andrea M Quattrini
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, 10th St. & Constitution Ave. NW, Washington, DC, 20560, USA.
| | - Karen E Snyder
- Department of Biology, Harvey Mudd College, Claremont, CA, 91711, USA
| | | | - Isabela G L Seiblitz
- Centre for Marine Biology, University of São Paulo, São Sebastião, 11612-109, Brazil
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, 05508-900, Brazil
| | - Johnson Hoang
- Department of Biology, Harvey Mudd College, Claremont, CA, 91711, USA
| | - Natasha Floerke
- Department of Biology, Harvey Mudd College, Claremont, CA, 91711, USA
| | - Nina I Ramos
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, 10th St. & Constitution Ave. NW, Washington, DC, 20560, USA
| | - Herman H Wirshing
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, 10th St. & Constitution Ave. NW, Washington, DC, 20560, USA
| | - Estefanía Rodriguez
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA
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3
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Ramos NI, DeLeo DM, Horowitz J, McFadden CS, Quattrini AM. Selection in coral mitogenomes, with insights into adaptations in the deep sea. Sci Rep 2023; 13:6016. [PMID: 37045882 PMCID: PMC10097804 DOI: 10.1038/s41598-023-31243-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/08/2023] [Indexed: 04/14/2023] Open
Abstract
Corals are a dominant benthic fauna that occur across a vast range of depths from just below the ocean's surface to the abyssopelagic zone. However, little is known about the evolutionary mechanisms that enable them to inhabit such a wide range of environments. The mitochondrial (mt) genome, which is involved in energetic pathways, may be subject to selection pressures at greater depths to meet the metabolic demands of that environment. Here, we use a phylogenomic framework combined with codon-based models to evaluate whether mt protein-coding genes (PCGs) associated with cellular energy functions are under positive selection across depth in three groups of corals: Octocorallia, Scleractinia, and Antipatharia. The results demonstrated that mt PCGs of deep- and shallow-water species of all three groups were primarily under strong purifying selection (0.0474 < ω < 0.3123), with the exception of positive selection in atp6 (ω = 1.3263) of deep-sea antipatharians. We also found evidence for positive selection at fifteen sites across cox1, mtMutS, and nad1 in deep-sea octocorals and nad3 of deep-sea antipatharians. These results contribute to our limited understanding of mt adaptations as a function of depth and provide insight into the molecular response of corals to the extreme deep-sea environment.
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Affiliation(s)
- Nina I Ramos
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, USA
| | - Danielle M DeLeo
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, USA
| | - Jeremy Horowitz
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, USA
| | | | - Andrea M Quattrini
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, USA.
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4
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Hogan RI, Hopkins K, Wheeler AJ, Yesson C, Allcock AL. Evolution of mitochondrial and nuclear genomes in Pennatulacea. Mol Phylogenet Evol 2023; 178:107630. [PMID: 36182053 DOI: 10.1016/j.ympev.2022.107630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 08/31/2022] [Accepted: 09/19/2022] [Indexed: 12/14/2022]
Abstract
We examine the phylogeny of sea pens using sequences of whole mitochondrial genomes and the nuclear ribosomal cluster generated through low coverage Illumina sequencing. Taxon sampling includes 30 species in 19 genera representing 13 families. Ancestral state reconstruction shows that most sea pen mitochondrial genomes have the ancestral gene order, and that Pennatulacea with diverse gene orders are found in a single clade. The monophyly of Pennatulidae and Protoptilidae are rejected by both the mitochondrial and nuclear dataset, while the mitochondrial dataset further rejects monophyly of Virgulariidae, and the nuclear dataset rejects monophyly of Kophobelemnidae. We show discordance between nuclear ribosomal gene cluster phylogenies and whole mitochondrial genome phylogenies and highlight key Pennatulacea taxa that could be included in cnidarian genome-wide studies to better resolve the sea pen tree of life. We further illustrate how well frequently sequenced markers capture the overall diversity of the mitochondrial genome and the nuclear ribosomal genes in sea pens.
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Affiliation(s)
- Raissa I Hogan
- School of Natural Sciencecs & Ryan Institute, University of Galway, University Road, Galway, Ireland
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, Regent's Park, London, UK
| | - Andrew J Wheeler
- School of Biological, Earth & Environmental Science, Irish Centre for Research in Applied Geosciences, University College Cork, Ireland
| | - Chris Yesson
- Institute of Zoology, Zoological Society of London, Regent's Park, London, UK
| | - A Louise Allcock
- School of Natural Sciencecs & Ryan Institute, University of Galway, University Road, Galway, Ireland.
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5
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Kushida Y, Imahara Y, Wee HB, Fernandez-Silva I, Fromont J, Gomez O, Wilson N, Kimura T, Tsuchida S, Fujiwara Y, Higashiji T, Nakano H, Kohtsuka H, Iguchi A, Reimer JD. Exploring the trends of adaptation and evolution of sclerites with regards to habitat depth in sea pens. PeerJ 2022; 10:e13929. [PMID: 36164604 PMCID: PMC9508890 DOI: 10.7717/peerj.13929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/31/2022] [Indexed: 01/19/2023] Open
Abstract
Octocorals possess sclerites, small elements comprised of calcium carbonate (CaCO3) that are important diagnostic characters in octocoral taxonomy. Among octocorals, sea pens comprise a unique order (Pennatulacea) that live in a wide range of depths. Habitat depth is considered to be important in the diversification of octocoral species, but a lack of information on sea pens has limited studies on their adaptation and evolution across depth. Here, we aimed to reveal trends of adaptation and evolution of sclerite shapes in sea pens with regards to habitat depth via phylogenetic analyses and ancestral reconstruction analyses. Colony form of sea pens is suggested to have undergone convergent evolution and the loss of axis has occurred independently across the evolution of sea pens. Divergences of sea pen taxa and of sclerite forms are suggested to depend on habitat depths. In addition, their sclerite forms may be related to evolutionary history of the sclerite and the surrounding chemical environment as well as water temperature. Three-flanged sclerites may possess the tolerance towards the environment of the deep sea, while plate sclerites are suggested to be adapted towards shallower waters, and have evolved independently multiple times. The common ancestor form of sea pens was predicted to be deep-sea and similar to family Pseudumbellulidae in form, possessing sclerites intermediate in form to those of alcyonaceans and modern sea pens such as spindles, rods with spines, and three-flanged sclerites with serrated edges sclerites, as well as having an axis and bilateral traits.
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Affiliation(s)
- Yuka Kushida
- Faculty of Geo-Environmental Science, Rissho University, Kumagaya, Saitama, Japan,Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan,International Center for Island Studies Amami Station, Kagoshima University, Amami, Kagoshima, Japan,Molecular Invertebrate Systematics and Ecology Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Yukimitsu Imahara
- Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan,Kuroshio Biological Research Foundation, Otsuchi, Kochi, Japan,Octocoral Research Laboratory, Wakayama, Wakayama, Japan
| | - Hin Boo Wee
- Institut Perubahan Iklim, Universiti Kebangsaan Malaysia, Selangor Darul Ehsan, Malaysia
| | - Iria Fernandez-Silva
- Department of Biochemistry, Genetics and Immunology, Campus Universitario, University of Vigo, Vigo, Spain
| | - Jane Fromont
- Collections & Research, Western Australian Museum, Welshpool, Western Australia, Australia
| | - Oliver Gomez
- Collections & Research, Western Australian Museum, Welshpool, Western Australia, Australia
| | - Nerida Wilson
- Collections & Research, Western Australian Museum, Welshpool, Western Australia, Australia,School of Biological Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Taeko Kimura
- Department of Life Sciences, Graduate School of Bioresources, Mie University, Tsu, Mie, Japan
| | - Shinji Tsuchida
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
| | - Yoshihiro Fujiwara
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
| | - Takuo Higashiji
- Okinawa Churaumi Aquarium, Okinawa Churashima Foundation, Motobu, Okinawa, Japan
| | - Hiroaki Nakano
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Hisanori Kohtsuka
- Misaki Marine Biological Station, Graduate School of Science, University of Tokyo, Miura, Kanagawa, Japan
| | - Akira Iguchi
- Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan,Research Laboratory on Environmentally-Conscious Developments and Technologies [E-Code], National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - James Davis Reimer
- Molecular Invertebrate Systematics and Ecology Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan,Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa, Japan
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6
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López-González PJ, Drewery J. When distant relatives look too alike: a new family, two new genera and a new species of deep-sea. INVERTEBR SYST 2022. [DOI: 10.1071/is21040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Among octocorals, colonies of the deep-sea pennatulacean genus Umbellula Gray, 1870 are some of the most instantly recognisable forms. Historically however, species identification in this genus has been usually based on few morphological characters with very little knowledge of associated intraspecific variability. This fact, combined with the very limited access to these deep-sea organisms, has resulted in numerous uncertainties about the true characters that should be used in species determination and recognition of synonyms and questionable species. Recent phylogenetic analyses based on mitochondrial and nuclear DNA markers has shown to be an excellent complementary source of information to morphological examination, being able to detect incongruent taxonomic assignments in classifications based only on morphological characters. Molecular analyses can reveal the presence of paraphyletic or polyphyletic groupings of taxa that may then be the subject of further research integrating morphological and molecular techniques. This paper addresses the existence of a set of specimens initially assigned to the genus Umbellula Gray, 1870 but that have been shown to be distantly related to the type species Umbellula encrinus (Linnaeus, 1758) based on molecular phylogenetic hypotheses. Phylogenetic analyses based on four genetic markers, three mitochondrial (mtMutS, ND2, Cox1) and one nuclear (28S), validate the definition of a new family (Pseudumbellulidae fam. nov.) and two new genera (Pseudumbellula gen. nov. and Solumbellula gen. nov). These analyses also justify the segregation of some of the morphological characters previously included in the diagnosis of the genus Umbellula and the monotypic family Umbellulidae Kölliker, 1880. Moreover, a new species, Pseudumbellula scotiae sp. nov. is described and illustrated with material from the North Eastern Atlantic and compared with congeners. Additionally, the well-known but atypical species Umbellula monocephalus Pasternak, 1964 is transferred and described here as Solumbellula monocephalus (Pasternak, 1964), comb. nov., based on both molecular data and morphology.
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Zhang K, Sun J, Xu T, Qiu JW, Qian PY. Phylogenetic Relationships and Adaptation in Deep-Sea Mussels: Insights from Mitochondrial Genomes. Int J Mol Sci 2021; 22:ijms22041900. [PMID: 33672964 PMCID: PMC7918742 DOI: 10.3390/ijms22041900] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/31/2021] [Accepted: 02/08/2021] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial genomes (mitogenomes) are an excellent source of information for phylogenetic and evolutionary studies, but their application in marine invertebrates is limited. In the present study, we utilized mitogenomes to elucidate the phylogeny and environmental adaptation in deep-sea mussels (Mytilidae: Bathymodiolinae). We sequenced and assembled seven bathymodioline mitogenomes. A phylogenetic analysis integrating the seven newly assembled and six previously reported bathymodioline mitogenomes revealed that these bathymodiolines are divided into three well-supported clades represented by five Gigantidas species, six Bathymodiolus species, and two "Bathymodiolus" species, respectively. A Common interval Rearrangement Explorer (CREx) analysis revealed a gene order rearrangement in bathymodiolines that is distinct from that in other shallow-water mytilids. The CREx analysis also suggested that reversal, transposition, and tandem duplications with subsequent random gene loss (TDRL) may have been responsible for the evolution of mitochondrial gene orders in bathymodiolines. Moreover, a comparison of the mitogenomes of shallow-water and deep-sea mussels revealed that the latter lineage has experienced relaxed purifying selection, but 16 residues of the atp6, nad4, nad2, cob, nad5, and cox2 genes have underwent positive selection. Overall, this study provides new insights into the phylogenetic relationships and mitogenomic adaptations of deep-sea mussels.
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Affiliation(s)
- Kai Zhang
- Department of Ocean Science, Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong 93117, China; (K.Z.); (J.S.); (T.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510225, China
| | - Jin Sun
- Department of Ocean Science, Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong 93117, China; (K.Z.); (J.S.); (T.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510225, China
| | - Ting Xu
- Department of Ocean Science, Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong 93117, China; (K.Z.); (J.S.); (T.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510225, China
- Department of Biology, Hong Kong Baptist University, Hong Kong 93117, China
| | - Jian-Wen Qiu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510225, China
- Department of Biology, Hong Kong Baptist University, Hong Kong 93117, China
- Correspondence: (J.-W.Q.); (P.-Y.Q.)
| | - Pei-Yuan Qian
- Department of Ocean Science, Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong 93117, China; (K.Z.); (J.S.); (T.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510225, China
- Correspondence: (J.-W.Q.); (P.-Y.Q.)
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8
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Seiblitz IGL, Capel KCC, Stolarski J, Quek ZBR, Huang D, Kitahara MV. The earliest diverging extant scleractinian corals recovered by mitochondrial genomes. Sci Rep 2020; 10:20714. [PMID: 33244171 PMCID: PMC7693180 DOI: 10.1038/s41598-020-77763-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/11/2020] [Indexed: 11/08/2022] Open
Abstract
Evolutionary reconstructions of scleractinian corals have a discrepant proportion of zooxanthellate reef-building species in relation to their azooxanthellate deep-sea counterparts. In particular, the earliest diverging "Basal" lineage remains poorly studied compared to "Robust" and "Complex" corals. The lack of data from corals other than reef-building species impairs a broader understanding of scleractinian evolution. Here, based on complete mitogenomes, the early onset of azooxanthellate corals is explored focusing on one of the most morphologically distinct families, Micrabaciidae. Sequenced on both Illumina and Sanger platforms, mitogenomes of four micrabaciids range from 19,048 to 19,542 bp and have gene content and order similar to the majority of scleractinians. Phylogenies containing all mitochondrial genes confirm the monophyly of Micrabaciidae as a sister group to the rest of Scleractinia. This topology not only corroborates the hypothesis of a solitary and azooxanthellate ancestor for the order, but also agrees with the unique skeletal microstructure previously found in the family. Moreover, the early-diverging position of micrabaciids followed by gardineriids reinforces the previously observed macromorphological similarities between micrabaciids and Corallimorpharia as well as its microstructural differences with Gardineriidae. The fact that both families share features with family Kilbuchophylliidae ultimately points towards a Middle Ordovician origin for Scleractinia.
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Affiliation(s)
- Isabela G L Seiblitz
- Departamento de Ciências do Mar, Universidade Federal de São Paulo, Santos, São Paulo, Brazil.
- Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, São Paulo, Brazil.
| | - Kátia C C Capel
- Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, São Paulo, Brazil
| | | | | | - Danwei Huang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
| | - Marcelo V Kitahara
- Departamento de Ciências do Mar, Universidade Federal de São Paulo, Santos, São Paulo, Brazil
- Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, São Paulo, Brazil
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9
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Smith DR. Revisiting Ceriantharian (Anthozoa) Mitochondrial Genomes: Casting Doubts about Their Structure and Size. Genome Biol Evol 2020; 12:1440-1443. [PMID: 32589745 PMCID: PMC7487158 DOI: 10.1093/gbe/evaa130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2020] [Indexed: 01/22/2023] Open
Abstract
Recently, Stampar et al. (2019. Linear mitochondrial genome in Anthozoa (Cnidaria): a case study in. Sci Rep. 9(1):6094.) uncovered highly atypical mitochondrial genome structures in the cnidarian species Pachycerianthus magnus and Isarachnanthus nocturnus (Anthozoa, Ceriantharia). These two mitochondrial DNAs assembled as linear fragmented genomes, comprising eight and five chromosomes, respectively—architectures unlike any other anthozoan mitogenome described to date. What’s more, they have cumulative lengths of 77.8 (P. magnus) and 80.9 kb (I. nocturnus), making them the largest animal mitochondrial DNAs on record, a finding which garnered significant attention by various news media. Here, I take a closer look at the work of Stampar et al. and question their key results. I provide evidence that the currently available mitogenome sequences for I. nocturnus and P. magnus, including their structures, sizes, and chromosome numbers, should be treated with caution. More work must be done on these genomes before one can say with any certainty that they are linear, fragmented, or the largest animal mitogenomes observed to date.
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Affiliation(s)
- David Roy Smith
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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10
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Comparative Analysis of Complete Mitochondrial Genomes of Three Gerres Fishes (Perciformes: Gerreidae) and Primary Exploration of Their Evolution History. Int J Mol Sci 2020; 21:ijms21051874. [PMID: 32182936 PMCID: PMC7084342 DOI: 10.3390/ijms21051874] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/05/2020] [Accepted: 03/07/2020] [Indexed: 11/17/2022] Open
Abstract
Mitochondrial genome is a powerful molecule marker to explore phylogenetic relationships and reveal molecular evolution in ichthyological studies. Gerres species play significant roles in marine fishery, but its evolution has received little attention. To date, only two Gerres mitochondrial genomes were reported. In the present study, three mitogenomes of Gerres (Gerres filamentosus, Gerres erythrourus, and Gerres decacanthus) were systemically investigated. The lengths of the mitogenome sequences were 16,673, 16,728, and 16,871 bp for G. filamentosus, G. erythrourus, and G. decacanthus, respectively. Most protein-coding genes (PCGs) were initiated with the typical ATG codon and terminated with the TAA codon, and the incomplete termination codon T/TA could be detected in the three species. The majority of AT-skew and GC-skew values of the 13 PCGs among the three species were negative, and the amplitude of the GC-skew was larger than the AT-skew. The genetic distance and Ka/Ks ratio analyses indicated 13 PCGs were suffering purifying selection and the selection pressures were different from certain deep-sea fishes, were which most likely due to the difference in their living environment. The phylogenetic tree was constructed by molecular method (Bayesian Inference (BI) and maximum Likelihood (ML)), providing further supplement to the scientific classification of fish. Three Gerres species were differentiated in late Cretaceous and early Paleogene, and their evolution might link with the geological events that could change their survival environment.
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11
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Bathyptilones: Terpenoids from an Antarctic Sea Pen, Anthoptilum grandiflorum (Verrill, 1879). Mar Drugs 2019; 17:md17090513. [PMID: 31480497 PMCID: PMC6780369 DOI: 10.3390/md17090513] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/28/2022] Open
Abstract
: An Antarctic coral belonging to the order Pennatulacea, collected during the 2013 austral autumn by trawl from 662 to 944 m depth, has yielded three new briarane diterpenes, bathyptilone A-C (1-3) along with a trinorditerpene, enbepeanone A (4), which bears a new carbon skeleton. Structure elucidation was facilitated by one- and two-dimensional NMR spectroscopy, mass spectrometry and confirmed by X-ray crystallography. The three compounds were screened in four cancer cell lines. Bathyptilone A displayed selective nanomolar cytotoxicity against the neurogenic mammalian cell line Ntera-2.
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