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Yap-Chiongco MK, Bergmeier FS, Roberts NG, Jörger KM, Kocot KM. Phylogenomic reconstruction of Solenogastres (Mollusca, Aplacophora) informs hypotheses on body size evolution. Mol Phylogenet Evol 2024; 194:108029. [PMID: 38341006 DOI: 10.1016/j.ympev.2024.108029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/24/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Body size is a fundamental characteristic of animals that impacts every aspect of their biology from anatomical complexity to ecology. In Mollusca, Solenogastres has been considered important to understanding the group's early evolution as most morphology-based phylogenetic reconstructions placed it as an early branching molluscan lineage. Under this scenario, molluscs were thought to have evolved from a small, turbellarian-like ancestor and small (i.e., macrofaunal) body size was inferred to be plesiomorphic for Solenogastres. More recently, phylogenomic studies have shown that aplacophorans (Solenogastres + Caudofoveata) form a clade with chitons (Polyplacophora), which is sister to all other molluscs, suggesting a relatively large-bodied (i.e., megafaunal) ancestor for Mollusca. Meanwhile, recent investigations into aplacophoran phylogeny have called the assumption that the last common ancestor of Solenogastres was small-bodied into question, but sampling of meiofaunal species was limited, biasing these studies towards large-bodied taxa and leaving fundamental questions about solenogaster body size evolution unanswered. Here, we supplemented available data with transcriptomes from eight diverse meiofaunal species of Solenogastres and conducted phylogenomic analyses on datasets of up to 949 genes. Maximum likelihood analyses support the meiofaunal family Meiomeniidae as the sister group to all other solenogasters, congruent with earlier ideas of a small-bodied ancestor of Solenogastres. In contrast, Bayesian Inference analyses support the large-bodied family Amphimeniidae as the sister group to all other solenogasters. Investigation of phylogenetic signal by comparing site-wise likelihood scores for the two competing hypotheses support the Meiomeniidae-first topology. In light of these results, we performed ancestral character state reconstruction to explore the implications of both hypotheses on understanding of Solenogaster evolution and review previous hypotheses about body size evolution and its potential consequences for solenogaster biology. Both hypotheses imply that body size evolution has been highly dynamic over the course of solenogaster evolution and that their relatively static body plan has successfully allowed for evolutionary transitions between meio-, macro- and megafaunal size ranges.
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Affiliation(s)
| | | | - Nickellaus G Roberts
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA
| | - Katharina M Jörger
- SNSB-Bavarian State Collection for Zoology, Section Mollusca, Munich, Germany
| | - Kevin M Kocot
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA; Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, AL, USA.
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Saadi AJ, de Oliveira AL, Kocot KM, Schwaha T. Genomic and transcriptomic survey of bryozoan Hox and ParaHox genes with emphasis on phylactolaemate bryozoans. BMC Genomics 2023; 24:711. [PMID: 38001438 PMCID: PMC10675955 DOI: 10.1186/s12864-023-09826-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/22/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Bryozoans are mostly sessile aquatic colonial invertebrates belonging to the clade Lophotrochozoa, which unites many protostome bilaterian phyla such as molluscs, annelids and brachiopods. While Hox and ParaHox genes have been extensively studied in various lophotrochozoan lineages, investigations on Hox and ParaHox gene complements in bryozoans are scarce. RESULTS Herein, we present the most comprehensive survey of Hox and ParaHox gene complements in bryozoans using four genomes and 35 transcriptomes representing all bryozoan clades: Cheilostomata, Ctenostomata, Cyclostomata and Phylactolaemata. Using similarity searches, phylogenetic analyses and detailed manual curation, we have identified five Hox genes in bryozoans (pb, Dfd, Lox5, Lox4 and Post2) and one ParaHox gene (Cdx). Interestingly, we observed lineage-specific duplication of certain Hox and ParaHox genes (Dfd, Lox5 and Cdx) in some bryozoan lineages. CONCLUSIONS The bryozoan Hox cluster does not retain the ancestral lophotrochozoan condition but appears relatively simple (includes only five genes) and broken into two genomic regions, characterized by the loss and duplication of serval genes. Importantly, bryozoans share the lack of two Hox genes (Post1 and Scr) with their proposed sister-taxon, Phoronida, which suggests that those genes were missing in the most common ancestor of bryozoans and phoronids.
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Affiliation(s)
- Ahmed J Saadi
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Schlachthausgasse 43, Vienna, A-1030, Austria.
| | - André Luiz de Oliveira
- Department of Symbiosis, Max-Planck-Institute for Marine Microbiology, Celsiustraße,1, D-28359, Bremen, Germany
| | - Kevin M Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, Alabama, 35487, USA
| | - Thomas Schwaha
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Schlachthausgasse 43, Vienna, A-1030, Austria
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Song H, Wang Y, Shao H, Li Z, Hu P, Yap-Chiongco MK, Shi P, Zhang T, Li C, Wang Y, Ma P, Vinther J, Wang H, Kocot KM. Scaphopoda is the sister taxon to Bivalvia: Evidence of ancient incomplete lineage sorting. Proc Natl Acad Sci U S A 2023; 120:e2302361120. [PMID: 37738291 PMCID: PMC10556646 DOI: 10.1073/pnas.2302361120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 08/18/2023] [Indexed: 09/24/2023] Open
Abstract
The almost simultaneous emergence of major animal phyla during the early Cambrian shaped modern animal biodiversity. Reconstructing evolutionary relationships among such closely spaced branches in the animal tree of life has proven to be a major challenge, hindering understanding of early animal evolution and the fossil record. This is particularly true in the species-rich and highly varied Mollusca where dramatic inconsistency among paleontological, morphological, and molecular evidence has led to a long-standing debate about the group's phylogeny and the nature of dozens of enigmatic fossil taxa. A critical step needed to overcome this issue is to supplement available genomic data, which is plentiful for well-studied lineages, with genomes from rare but key lineages, such as Scaphopoda. Here, by presenting chromosome-level genomes from both extant scaphopod orders and leveraging complete genomes spanning Mollusca, we provide strong support for Scaphopoda as the sister taxon of Bivalvia, revitalizing the morphology-based Diasoma hypothesis originally proposed 50 years ago. Our molecular clock analysis confidently dates the split between Bivalvia and Scaphopoda at ~520 Ma, prompting a reinterpretation of controversial laterally compressed Early Cambrian fossils, including Anabarella, Watsonella, and Mellopegma, as stem diasomes. Moreover, we show that incongruence in the phylogenetic placement of Scaphopoda in previous phylogenomic studies was due to ancient incomplete lineage sorting (ILS) that occurred during the rapid radiation of Conchifera. Our findings highlight the need to consider ILS as a potential source of error in deep phylogeny reconstruction, especially in the context of the unique nature of the Cambrian Explosion.
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Affiliation(s)
- Hao Song
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Yunan Wang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Haojing Shao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518000, China
| | - Zhuoqing Li
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Pinli Hu
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518000, China
| | | | - Pu Shi
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Tao Zhang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Cui Li
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Yiguan Wang
- Institute of Ecology and Evolution, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
| | - Peizhen Ma
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Jakob Vinther
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
- School of Earth Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
| | - Haiyan Wang
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Kevin M. Kocot
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL35487
- Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL35487
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Jabr N, Gonzalez P, Kocot KM, Cameron CB. The embryology, metamorphosis, and muscle development of Schizocardium karankawa sp. nov. (Enteropneusta) from the Gulf of Mexico. EvoDevo 2023; 14:6. [PMID: 37076909 PMCID: PMC10114407 DOI: 10.1186/s13227-023-00212-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
Schizocardium karankawa sp. nov. has been collected from subtidal muds of the Laguna Madre, Texas, and the Mississippi coast, Gulf of Mexico. The Texas population is reproductive from early February to mid-April. Gametes are liberated by a small incision in a gonad. Oocyte germinal vesicle breakdown is increased in the presence of sperm, and the highest fertilization success was in the artificial seawater Jamarin U. Manually dechorionated embryos develop normally. Development was asynchronous via a tornaria larva, metamorphosis and maintained to the juvenile worm 6 gill-pore stage. Phalloidin-labeled late-stage tornaria revealed retractor muscles that connect the pericardial sac with the apical tuft anteriorly, the oesophagus ventrally, and muscle cells of the early mesocoels. The muscle development of early juvenile worms began with dorso-lateral trunk muscles, lateral trunk bands, and sphincters around the gill pores and anus. Adult worms are characterized by a stomochord that bifurcates anteriorly into paired vermiform processes, gill bars that extend almost the entire dorsal to ventral branchial region resulting in a narrow ventral hypobranchial ridge, and an elaborate epibranchial organ with six zones of discrete cell types. The trunk has up to three rows of liver sacs, and lateral gonads. The acorn worm evo-devo model species Saccoglossus kowalevskii, Ptychodera flava, and Schizocardium californicum are phylogenetically distant with disparate life histories. S. karnakawa from S. californicum are phylogenetically close, and differences between them that become apparent as adult worms include the number of gill pores and hepatic sacs, and elaborations of the heart-kidney-stomochord complex. An important challenge for evolutionary developmental biology is to form links from phylogenetically distant and large-scale differences to phylogenetically close and small-scale differences. This description of the embryology, development, and adult morphology of S. karankawa permits investigations into how acorn worm development evolves at fine scales.
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Affiliation(s)
- Noura Jabr
- Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada
| | - Paul Gonzalez
- Computational and Statistical Genomics Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kevin M Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, Alabama, 35487, USA
| | - Christopher B Cameron
- Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada.
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McCutcheon MG, Kocot KM, Carmen Cobo M. Uncovering the biodiversity of New Zealand Solenogastres (Mollusca, Aplacophora) with three new species of Proneomeniidae Simroth, 1893 and new data for Dorymenia quincarinata (Ponder, 1970). Molluscan Research 2022. [DOI: 10.1080/13235818.2022.2143069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | - Kevin M. Kocot
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA
- Alabama Museum of Natural History, Tuscaloosa, AL, USA
| | - M. Carmen Cobo
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA
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Kocot KM, Todt C, Mikkelsen NT, Halanych KM. Correction to: ‘Phylogenomics of Aplacophora (Mollusca, Aculifera) and a solenogaster without a foot’ (2019) by Kocot
et al.. Proc Biol Sci 2022; 289:20222057. [PMID: 36350223 PMCID: PMC9653252 DOI: 10.1098/rspb.2022.2057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Saadi AJ, Bibermair J, Kocot KM, Roberts NG, Hirose M, Calcino A, Baranyi C, Chaichana R, Wood TS, Schwaha T. Phylogenomics reveals deep relationships and diversification within phylactolaemate bryozoans. Proc Biol Sci 2022; 289:20221504. [PMID: 36350215 PMCID: PMC9653232 DOI: 10.1098/rspb.2022.1504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2022] [Indexed: 11/02/2023] Open
Abstract
Bryozoans are mostly sessile colonial invertebrates that inhabit all kinds of aquatic ecosystems. Extant bryozoan species fall into two clades with one of them, Phylactolaemata, being the only exclusively freshwater clade. Phylogenetic relationships within the class Phylactolaemata have long been controversial owing to their limited distinguishable characteristics that reflect evolutionary relationships. Here, we present the first phylogenomic analysis of Phylactolaemata using transcriptomic data combined with dense taxon sampling of six families to better resolve the interrelationships and to estimate divergence time. Using maximum-likelihood and Bayesian inference approaches, we recovered a robust phylogeny for Phylactolaemata in which the interfamilial relationships are fully resolved. We show Stephanellidae is the sister taxon of all other phylactolaemates and confirm that Lophopodidae represents the second offshoot within the phylactolaemate tree. Plumatella fruticosa clearly falls outside Plumatellidae as previous investigations have suggested, and instead clusters with Pectinatellidae and Cristatellidae as the sister taxon of Fredericellidae. Our results demonstrate that cryptic speciation is very likely in F. sultana and in two species of Plumatella (P. repens and P. casmiana). Divergence time estimates show that Phylactolaemata appeared at the end of the Ediacaran and started to diverge in the Silurian, although confidence intervals were large for most nodes. The radiation of most extant phylactolaemate families occurred mainly in the Palaeogene and Neogene highlighting post-extinction diversification.
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Affiliation(s)
- Ahmed J. Saadi
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Julian Bibermair
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nickellaus G. Roberts
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Masato Hirose
- School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Sagamihara-Minami, Kanagawa 252-0373, Japan
| | - Andrew Calcino
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Christian Baranyi
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Ratcha Chaichana
- Department of Environmental Technology and Management, Faculty of Environment, Kasetsart University, Bangkok, Thailand
| | - Timothy S. Wood
- Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA
| | - Thomas Schwaha
- Department of Evolutionary Biology, Unit for Integrative Zoology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
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Drábková M, Kocot KM, Halanych KM, Oakley TH, Moroz LL, Cannon JT, Kuris A, Garcia-Vedrenne AE, Pankey MS, Ellis EA, Varney R, Štefka J, Zrzavý J. Different phylogenomic methods support monophyly of enigmatic 'Mesozoa' (Dicyemida + Orthonectida, Lophotrochozoa). Proc Biol Sci 2022; 289:20220683. [PMID: 35858055 PMCID: PMC9257288 DOI: 10.1098/rspb.2022.0683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dicyemids and orthonectids were traditionally classified in a group called Mesozoa, but their placement in a single clade has been contested and their position(s) within Metazoa is uncertain. Here, we assembled a comprehensive matrix of Lophotrochozoa (Metazoa) and investigated the position of Dicyemida (= Rhombozoa) and Orthonectida, employing multiple phylogenomic approaches. We sequenced seven new transcriptomes and one draft genome from dicyemids (Dicyema, Dicyemennea) and two transcriptomes from orthonectids (Rhopalura). Using these and published data, we assembled and analysed contamination-filtered datasets with up to 987 genes. Our results recover Mesozoa monophyletic and as a close relative of Platyhelminthes or Gnathifera. Because of the tendency of the long-branch mesozoans to group with other long-branch taxa in our analyses, we explored the impact of approaches purported to help alleviate long-branch attraction (e.g. taxon removal, coalescent inference, gene targeting). None of these were able to break the association of Orthonectida with Dicyemida in the maximum-likelihood trees. Contrastingly, the Bayesian analysis and site-specific frequency model in maximum-likelihood did not recover a monophyletic Mesozoa (but only when using a specific 50 gene matrix). The classic hypothesis on monophyletic Mesozoa is possibly reborn and should be further tested.
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Affiliation(s)
- Marie Drábková
- Department of Parasitology, University of South Bohemia, České Budějovice 37005, Czech Republic,Laboratory of Molecular Ecology and Evolution, Institute of Parasitology, Biology Centre CAS, České Budějovice 37005, Czech Republic
| | - Kevin M. Kocot
- Department of Biological Sciences, The University of Alabama, Campus Box 870344, Tuscaloosa, AL 35487, USA
| | - Kenneth M. Halanych
- The Centre for Marine Science, University of North Carolina, Wilmington, 57000 Marvin K. Moss Lane, Wilmington, NC 28409, USA
| | - Todd H. Oakley
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Leonid L. Moroz
- Department of Neuroscience, and the Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Boulevard, St Augustine, FL 32080, USA
| | - Johanna T. Cannon
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Armand Kuris
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ana Elisa Garcia-Vedrenne
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - M. Sabrina Pankey
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Emily A. Ellis
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Rebecca Varney
- Department of Biological Sciences, The University of Alabama, Campus Box 870344, Tuscaloosa, AL 35487, USA,Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Jan Štefka
- Department of Parasitology, University of South Bohemia, České Budějovice 37005, Czech Republic,Laboratory of Molecular Ecology and Evolution, Institute of Parasitology, Biology Centre CAS, České Budějovice 37005, Czech Republic
| | - Jan Zrzavý
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice 37005, Czech Republic
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Abstract
Mollusca is the second most species-rich phylum and includes animals as disparate as octopuses, clams, and chitons. Dozens of molluscan genomes are available, but only one representative of the subphylum Aculifera, the sister taxon to all other molluscs, has been sequenced to date, hindering comparative and evolutionary studies. To facilitate evolutionary studies across Mollusca, we sequenced the genome of a second aculiferan mollusc, the lepidopleurid chiton
Hanleya hanleyi (Bean 1844), using a hybrid approach combining Oxford Nanopore and Illumina reads. After purging redundant haplotigs and removing contamination from this 1.3% heterozygous genome, we produced a 2.5 Gbp haploid assembly (>4X the size of the other chiton genome sequenced to date) with an N50 of 65.0 Kbp. Despite a fragmented assembly, the genome is rather complete (92.0% of BUSCOs detected; 79.4% complete plus 12.6% fragmented). Remarkably, the genome has the highest repeat content of any molluscan genome reported to date (>66%). Our gene annotation pipeline predicted 69,284 gene models (92.9% of BUSCOs detected; 81.8% complete plus 11.1% fragmented) of which 35,362 were supported by transcriptome and/or protein evidence. Phylogenomic analysis recovered Polyplacophora sister to all other sampled molluscs with maximal support. The
Hanleya genome will be a valuable resource for studies of molluscan biology with diverse potential applications ranging from evolutionary and comparative genomics to molecular ecology.
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Affiliation(s)
- Rebecca M. Varney
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Meghan K. Yap-Chiongco
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, 35487, USA
| | - Nina T. Mikkelsen
- University Museum of Bergen, Univeristy of Bergen, Bergen, 5020, Norway
| | - Kevin M. Kocot
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, 35487, USA
- Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, AL, 35487, USA
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Krug PJ, Caplins SA, Algoso K, Thomas K, Valdés ÁA, Wade R, Wong NLWS, Eernisse DJ, Kocot KM. Phylogenomic resolution of the root of Panpulmonata, a hyperdiverse radiation of gastropods: new insight into the evolution of air breathing. Proc Biol Sci 2022; 289:20211855. [PMID: 35382597 PMCID: PMC8984808 DOI: 10.1098/rspb.2021.1855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/21/2022] [Indexed: 11/12/2022] Open
Abstract
Transitions to terrestriality have been associated with major animal radiations including land snails and slugs in Stylommatophora (>20 000 described species), the most successful lineage of 'pulmonates' (a non-monophyletic assemblage of air-breathing gastropods). However, phylogenomic studies have failed to robustly resolve relationships among traditional pulmonates and affiliated marine lineages that comprise clade Panpulmonata (Mollusca, Gastropoda), especially two key taxa: Sacoglossa, a group including photosynthetic sea slugs, and Siphonarioidea, intertidal limpet-like snails with a non-contractile pneumostome (narrow opening to a vascularized pallial cavity). To clarify the evolutionary history of the panpulmonate radiation, we performed phylogenomic analyses on datasets of up to 1160 nuclear protein-coding genes for 110 gastropods, including 40 new transcriptomes for Sacoglossa and Siphonarioidea. All 18 analyses recovered Sacoglossa as the sister group to a clade we named Pneumopulmonata, within which Siphonarioidea was sister to the remaining lineages in most analyses. Comparative modelling indicated shifts to marginal habitat (estuarine, mangrove and intertidal zones) preceded and accelerated the evolution of a pneumostome, present in the pneumopulmonate ancestor along with a one-sided plicate gill. These findings highlight key intermediate stages in the evolution of air-breathing snails, supporting the hypothesis that adaptation to marginal zones played an important role in major sea-to-land transitions.
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Affiliation(s)
- Patrick J. Krug
- Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, USA
| | | | - Krisha Algoso
- Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, USA
| | - Kanique Thomas
- Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, USA
| | - Ángel A. Valdés
- Department of Biological Sciences, California State Polytechnic University, Pomona, CA 91768, USA
| | - Rachael Wade
- Department of Botany, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Nur Leena W. S. Wong
- International Institute of Aquaculture and Aquatic Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Douglas J. Eernisse
- Department of Biological Science, California State University, Fullerton, CA 92834, USA
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, AL 35487, USA
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Ahmed M, Roberts NG, Adediran F, Smythe AB, Kocot KM, Holovachov O. Phylogenomic Analysis of the Phylum Nematoda: Conflicts and Congruences With Morphology, 18S rRNA, and Mitogenomes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.769565] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Phylogenetic relationships within many lineages of the phylum Nematoda remain unresolved, despite numerous morphology-based and molecular analyses. We performed several phylogenomic analyses using 286 published genomes and transcriptomes and 19 new transcriptomes by focusing on Trichinellida, Spirurina, Rhabditina, and Tylenchina separately, and by analyzing a selection of species from the whole phylum Nematoda. The phylogeny of Trichinellida supported the division of Trichinella into encapsulated and non-encapsulated species and placed them as sister to Trichuris. The Spirurina subtree supported the clades formed by species from Ascaridomorpha and Spiruromorpha respectively, but did not support Dracunculoidea. The analysis of Tylenchina supported a clade that included all sampled species from Tylenchomorpha and placed it as sister to clades that included sampled species from Cephalobomorpha and Panagrolaimomorpha, supporting the hypothesis that postulates the single origin of the stomatostylet. The Rhabditina subtree placed a clade composed of all sampled species from Diplogastridae as sister to a lineage consisting of paraphyletic Rhabditidae, a single representative of Heterorhabditidae and a clade composed of sampled species belonging to Strongylida. It also strongly supported all suborders within Strongylida. In the phylum-wide analysis, a clade composed of all sampled species belonging to Enoplia were consistently placed as sister to Dorylaimia + Chromadoria. The topology of the Nematoda backbone was consistent with previous studies, including polyphyletic placement of sampled representatives of Monhysterida and Araeolaimida.
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Maroni PJ, Baker BJ, Moran AL, Woods HA, Avila C, Johnstone GJ, Stark JS, Kocot KM, Lockhart S, Saucède T, Rouse GW, Wilson NG. One Antarctic slug to confuse them all: the underestimated diversity of Doris kerguelenensis. INVERTEBR SYST 2022. [DOI: 10.1071/is21073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sun J, Li R, Chen C, Sigwart JD, Kocot KM. Benchmarking Oxford Nanopore read assemblers for high-quality molluscan genomes. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200160. [PMID: 33813888 PMCID: PMC8059532 DOI: 10.1098/rstb.2020.0160] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
Choosing the optimum assembly approach is essential to achieving a high-quality genome assembly suitable for comparative and evolutionary genomic investigations. Significant recent progress in long-read sequencing technologies such as PacBio and Oxford Nanopore Technologies (ONT) has also brought about a large variety of assemblers. Although these have been extensively tested on model species such as Homo sapiens and Drosophila melanogaster, such benchmarking has not been done in Mollusca, which lacks widely adopted model species. Molluscan genomes are notoriously rich in repeats and are often highly heterozygous, making their assembly challenging. Here, we benchmarked 10 assemblers based on ONT raw reads from two published molluscan genomes of differing properties, the gastropod Chrysomallon squamiferum (356.6 Mb, 1.59% heterozygosity) and the bivalve Mytilus coruscus (1593 Mb, 1.94% heterozygosity). By optimizing the assembly pipeline, we greatly improved both genomes from previously published versions. Our results suggested that 40-50X of ONT reads are sufficient for high-quality genomes, with Flye being the recommended assembler for compact and less heterozygous genomes exemplified by C. squamiferum, while NextDenovo excelled for more repetitive and heterozygous molluscan genomes exemplified by M. coruscus. A phylogenomic analysis using the two updated genomes with 32 other published high-quality lophotrochozoan genomes resulted in maximum support across all nodes, and we show that improved genome quality also leads to more complete matrices for phylogenomic inferences. Our benchmarking will ensure efficiency in future assemblies for molluscs and perhaps also for other marine phyla with few genomes available. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
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Affiliation(s)
- Jin Sun
- Institute of Evolution and Marine Biodiversity, Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao 266003, People's Republic of China
| | - Runsheng Li
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong, People's Republic of China
| | - Chong Chen
- X-STAR, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2–15 Natsushima-cho, Yokosuka, Kanagawa Prefecture 237-0061, Japan
| | - Julia D. Sigwart
- Senckenberg Museum, 60325 Frankfurt, Germany
- Marine Laboratory Queen's University Belfast, Portaferry, BT22 1PF, Northern Ireland
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL 35487, USA
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Cobo MC, Kocot KM. Erratum: M. CARMEN COBO amp; KEVIN M. KOCOT (2021) On the diversity of abyssal Dondersiidae (Mollusca: Aplacophora) with the description of a new genus, six new species, and a review of the family. Zootaxa, 4933: 063097. Zootaxa 2021; 4974:600600. [PMID: 34186578 DOI: 10.11646/zootaxa.4974.3.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Indexed: 11/04/2022]
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Cobo MC, Kocot KM. On the diversity of abyssal Dondersiidae (Mollusca: Aplacophora) with the description of a new genus, six new species, and a review of the family. Zootaxa 2021; 4933:zootaxa.4933.1.3. [PMID: 33756804 DOI: 10.11646/zootaxa.4933.1.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 11/04/2022]
Abstract
So far, of the 292 known species of solenogasters (Mollusca, Aplacophora), 62 belong to the clade Pholidoskepia Salvini-Plawen, 1978. Of these, only two have an abyssal distribution (3500-6000 m depth). Among Pholidoskepia, Dondersiidae Simroth, 1893 is the most diverse family. This study contributes to the knowledge of this family with the description of one new genus and six new species from the abyssal South Atlantic Ocean: Dondersia ? foraminosa sp. n., Nematomenia divae sp. n., Nematomenia brasiliensis sp. n., Nematomenia ? guineana sp. n., Helluoherpia vieiralaneroi sp. n. and Inopinatamenia (gen. n.) calamitosa sp. n. Specimens were collected during DIVA (Latitudinal Gradients of Deep-Sea BioDIVersity in the Atlantic Ocean) expeditions in the Guinea (DIVA 2 Me 63/2, 2005) and Brazil (DIVA 3 Me 79/1, 2008) Basins. Specimens were characterized based primarily on the sclerites and internal anatomy, which was studied using histology. The importance of the radula and mantle sclerites for taxonomy is emphasized. Amended diagnoses for the family and some genera within this family are provided. This contribution increases the described diversity of Dondersiidae to ten genera and 38 species and highlights the need for more study of solenogasters in the deep sea.
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Affiliation(s)
- M Carmen Cobo
- Department of Zoology, Genetics and Physycal Antrhopology, University of Santiago de Compostela. Rúa Lope Gómez de Marzoa, s/n.Campus Vida. 15782 Santiago de Compostela, Spain. Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama. 300 Hackberry Lane, Tuscaloosa, AL 35487, USA..
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Varney RM, Brenzinger B, Malaquias MAE, Meyer CP, Schrödl M, Kocot KM. Assessment of mitochondrial genomes for heterobranch gastropod phylogenetics. BMC Ecol Evol 2021; 21:6. [PMID: 33514315 PMCID: PMC7853304 DOI: 10.1186/s12862-020-01728-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/26/2020] [Indexed: 01/07/2023] Open
Abstract
Background Heterobranchia is a diverse clade of marine, freshwater, and terrestrial gastropod molluscs. It includes such disparate taxa as nudibranchs, sea hares, bubble snails, pulmonate land snails and slugs, and a number of (mostly small-bodied) poorly known snails and slugs collectively referred to as the “lower heterobranchs”. Evolutionary relationships within Heterobranchia have been challenging to resolve and the group has been subject to frequent and significant taxonomic revision. Mitochondrial (mt) genomes can be a useful molecular marker for phylogenetics but, to date, sequences have been available for only a relatively small subset of Heterobranchia. Results To assess the utility of mitochondrial genomes for resolving evolutionary relationships within this clade, eleven new mt genomes were sequenced including representatives of several groups of “lower heterobranchs”. Maximum likelihood analyses of concatenated matrices of the thirteen protein coding genes found weak support for most higher-level relationships even after several taxa with extremely high rates of evolution were excluded. Bayesian inference with the CAT + GTR model resulted in a reconstruction that is much more consistent with the current understanding of heterobranch phylogeny. Notably, this analysis recovered Valvatoidea and Orbitestelloidea in a polytomy with a clade including all other heterobranchs, highlighting these taxa as important to understanding early heterobranch evolution. Also, dramatic gene rearrangements were detected within and between multiple clades. However, a single gene order is conserved across the majority of heterobranch clades. Conclusions Analysis of mitochondrial genomes in a Bayesian framework with the site heterogeneous CAT + GTR model resulted in a topology largely consistent with the current understanding of heterobranch phylogeny. However, mitochondrial genomes appear to be too variable to serve as good phylogenetic markers for robustly resolving a number of deeper splits within this clade.
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Affiliation(s)
- Rebecca M Varney
- Department of Biological Sciences, The University of Alabama, Campus Box 870344, Tuscaloosa, AL, 35487, USA
| | - Bastian Brenzinger
- SNSB-Bavarian State Collection of Zoology, Münchhausenstr. 21, 81247, München, Germany
| | | | - Christopher P Meyer
- National Museum of Natural History, Smithsonian Institution, 10th St. & Constitution Ave. NW, Washington, D.C., 20560, USA
| | - Michael Schrödl
- SNSB-Bavarian State Collection of Zoology, Münchhausenstr. 21, 81247, München, Germany.,BioGeoCenter LMU (Ludwig Maximillion University Munich), University of Munich, Biozentrum, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Kevin M Kocot
- Department of Biological Sciences, The University of Alabama, Campus Box 870344, Tuscaloosa, AL, 35487, USA. .,Alabama Museum of Natural History, Campus Box 870344, Tuscaloosa, AL, 35487, USA.
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Abstract
Molluscs biomineralize structures that vary in composition, form, and function, prompting questions about the genetic mechanisms responsible for their production and the evolution of these mechanisms. Chitons (Mollusca, Polyplacophora) are a promising system for studies of biomineralization because they build a range of calcified structures including shell plates and spine- or scale-like sclerites. Chitons also harden the calcified teeth of their rasp-like radula with a coat of iron (as magnetite). Here we present the genome of the West Indian fuzzy chiton Acanthopleura granulata, the first from any aculiferan mollusc. The A. granulata genome contains homologs of many genes associated with biomineralization in conchiferan molluscs. We expected chitons to lack genes previously identified from pathways conchiferans use to make biominerals like calcite and nacre because chitons do not use these materials in their shells. Surprisingly, the A. granulata genome has homologs of many of these genes, suggesting that the ancestral mollusc may have had a more diverse biomineralization toolkit than expected. The A. granulata genome has features that may be specialized for iron biomineralization, including a higher proportion of genes regulated directly by iron than other molluscs. A. granulata also produces two isoforms of soma-like ferritin: one is regulated by iron and similar in sequence to the soma-like ferritins of other molluscs, and the other is constitutively translated and is not found in other molluscs. The A. granulata genome is a resource for future studies of molluscan evolution and biomineralization.
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Affiliation(s)
- Rebecca M Varney
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Daniel I Speiser
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina
| | - Carmel McDougall
- Australian Rivers Institute, Griffith University, Nathan, Queensland, Australia
| | - Bernard M Degnan
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Kevin M Kocot
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
- Alabama Museum of Natural History, Tuscaloosa, Alabama
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Ramírez-Guerrero GM, Kocot KM, Cameron CB. Zooid morphology and molecular phylogeny of the graptolite Rhabdopleura annulata (Hemichordata, Pterobranchia) from Heron Island, Australia. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2020-0049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rhabdopleura Allman, 1869 is one of the longest surviving animal genera. The five-known species are the only living Graptolithina, a group well known from their diverse Paleozoic fossil record. Here we add information on the soft-bodied zooids and molecular phylogenetics of Rhabdopleura annulata Norman, 1921, which was previously only known from its tubes. Tubes and zooids were collected from Heron Island, Queensland, Australia. Zooids have a single pair of tentaculated arms. Dark pigment granules are found throughout the body, and particularly dense in the pair of arms and the anterior lip of the cephalic shield. Colonies grow encrusted in and on coral debris. The tubes are either creeping or erect, but no stolon has been found. Inside of the coral matrix lacunae, the tube cortex formed a parchment-like wallpaper. Phylogenetic analysis based on combined 18S+16S rRNA sequences placed R. annulata as sister to the remaining rhabdopleurids, albeit with weak support. The biogeographic range of R. annulata extends from Indonesia to Tasmania, and New Zealand. Its occurrence on Heron Island does not extend this range, but highlights that rhabdopleurids may be more common, and in shallower waters, than previously appreciated, permitting further studies that may shed light on graptolite paleobiology.
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Affiliation(s)
- Greta M. Ramírez-Guerrero
- Département de sciences biologiques, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Kevin M. Kocot
- The University of Alabama and Alabama Museum of Natural History, 500 Hackberry Lane, Tuscaloosa, AL 35487, USA
| | - Christopher B. Cameron
- Département de sciences biologiques, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, QC H3C 3J7, Canada
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Abstract
Recent molecular phylogenetic investigations strongly supported the placement of the shell-less, worm-shaped aplacophoran molluscs (Solenogastres and Caudofoveata) and chitons (Polyplacophora) in a clade called Aculifera, which is the sister taxon of all other molluscs. Thus, understanding the evolutionary history of aculiferan molluscs is important for understanding early molluscan evolution. In particular, fundamental questions about evolutionary relationships within Aplacophora have long been unanswered. Here, we supplemented the paucity of available data with transcriptomes from 25 aculiferans and conducted phylogenomic analyses on datasets with up to 525 genes and 75 914 amino acid positions. Our results indicate that aplacophoran taxonomy requires revision as several traditionally recognized groups are non-monophyletic. Most notably, Cavibelonia, the solenogaster taxon defined by hollow sclerites, is polyphyletic, suggesting parallel evolution of hollow sclerites in multiple lineages. Moreover, we describe Apodomenia enigmatica sp. nov., a bizarre new species that appears to be a morphological intermediate between Solenogastres and Caudofoveata. This animal is not a missing link, however; molecular and morphological studies show that it is a derived solenogaster that lacks a foot, mantle cavity and radula. Taken together, these results shed light on the evolutionary history of Aplacophora and reveal a surprising degree of morphological plasticity within the group.
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Affiliation(s)
- Kevin M Kocot
- 1 The University of Alabama and the Alabama Museum of Natural History , 500 Hackberry Lane, Tuscaloosa, AL 35487 , USA
| | - Christiane Todt
- 2 Rådgivende Biologer AS , Edvard Griegs vei 3, 5059 Bergen , Norway
| | - Nina T Mikkelsen
- 3 University Museum of Bergen, The Natural History Collections, University of Bergen , Allégaten 41, 5007 Bergen , Norway
| | - Kenneth M Halanych
- 4 Department of Biological Sciences, Auburn University , Auburn, AL 36849 , USA
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Abstract
Complete mitochondrial genomes were determined for two scaphopod molluscs: the dentaliid Antalis entalis and an unidentified Antarctic gadilid. Both genomes are complete except, in Gadilida sp. indet., a short stretch of nad5 was undetermined and trnR could not be annotated. Organization of the Gadilida sp. genome is nearly identical to that previously reported for the gadilid Siphonodentalium whereas trnK, nad5, trnD, nad4, and nad4l are transposed to the opposite strand in the previously published Graptacme genome relative to that of Antalis. Phylogenetic analysis of the 13 protein-coding and 2 rRNA genes recovered Scaphopoda, Gadilida, and Dentaliida monophyletic with maximal support.
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Affiliation(s)
- Kevin M Kocot
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
| | - Tim Wollesen
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Rebecca M Varney
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
| | - Megan L Schwartz
- School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, WA, USA
| | - Gerhard Steiner
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
| | - Andreas Wanninger
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
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Varney RM, Funch P, Kocot KM, Sørensen MV. A new species of Echinoderes (Cyclorhagida: Echinoderidae) from the San Juan Islands, Washington State, USA, and insights into the kinorhynch transcriptome. ZOOL ANZ 2019. [DOI: 10.1016/j.jcz.2019.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Laumer CE, Fernández R, Lemer S, Combosch D, Kocot KM, Riesgo A, Andrade SCS, Sterrer W, Sørensen MV, Giribet G. Revisiting metazoan phylogeny with genomic sampling of all phyla. Proc Biol Sci 2019; 286:20190831. [PMID: 31288696 PMCID: PMC6650721 DOI: 10.1098/rspb.2019.0831] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 06/17/2019] [Indexed: 11/21/2022] Open
Abstract
Proper biological interpretation of a phylogeny can sometimes hinge on the placement of key taxa-or fail when such key taxa are not sampled. In this light, we here present the first attempt to investigate (though not conclusively resolve) animal relationships using genome-scale data from all phyla. Results from the site-heterogeneous CAT + GTR model recapitulate many established major clades, and strongly confirm some recent discoveries, such as a monophyletic Lophophorata, and a sister group relationship between Gnathifera and Chaetognatha, raising continued questions on the nature of the spiralian ancestor. We also explore matrix construction with an eye towards testing specific relationships; this approach uniquely recovers support for Panarthropoda, and shows that Lophotrochozoa (a subclade of Spiralia) can be constructed in strongly conflicting ways using different taxon- and/or orthologue sets. Dayhoff-6 recoding sacrifices information, but can also reveal surprising outcomes, e.g. full support for a clade of Lophophorata and Entoprocta + Cycliophora, a clade of Placozoa + Cnidaria, and raising support for Ctenophora as sister group to the remaining Metazoa, in a manner dependent on the gene and/or taxon sampling of the matrix in question. Future work should test the hypothesis that the few remaining uncertainties in animal phylogeny might reflect violations of the various stationarity assumptions used in contemporary inference methods.
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Affiliation(s)
- Christopher E. Laumer
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- EMBL-European Bioinformatics Institute (EBI), Wellcome Genome Campus, Hinxton CB10 1SD, UK
| | - Rosa Fernández
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Bioinformatics & Genomics Unit, Center for Genomic Regulation, Carrer del Dr. Aiguader 88, 08003 Barcelona (Spain)
| | - Sarah Lemer
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Marine Laboratory, University of Guam, UOG Station, Mangilao, Guam 96923, USA
| | - David Combosch
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Marine Laboratory, University of Guam, UOG Station, Mangilao, Guam 96923, USA
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Campus Box 870344, Tuscaoosa, AL 35487, USA
| | - Ana Riesgo
- Department of Life Sciences, Natural History Museum of London, Cromwell Road, London SW7 5BD, UK
| | - Sónia C. S. Andrade
- Departamento de Genética e Biologia Evolutiva, IB, Universidade de São Paulo, 05508090 São Paulo, SP, Brazil
| | - Wolfgang Sterrer
- Bermuda Natural History Museum, PO Box FL 145, Flatts, FLBX, Bermuda
| | - Martin V. Sørensen
- Natural History Museum of Denmark, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Gonzalo Giribet
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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Smythe AB, Holovachov O, Kocot KM. Improved phylogenomic sampling of free-living nematodes enhances resolution of higher-level nematode phylogeny. BMC Evol Biol 2019; 19:121. [PMID: 31195978 PMCID: PMC6567515 DOI: 10.1186/s12862-019-1444-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/27/2019] [Indexed: 11/18/2022] Open
Abstract
Background Nematodes are among the most diverse and abundant metazoans on Earth, but research on them has been biased toward parasitic taxa and model organisms. Free-living nematodes, particularly from the clades Enoplia and Dorylaimia, have been underrepresented in genome-scale phylogenetic analyses to date, leading to poor resolution of deep relationships within the phylum. Results We supplemented publicly available data by sequencing transcriptomes of nine free-living nematodes and two important outgroups and conducted a phylum-wide phylogenomic analysis including a total of 108 nematodes. Analysis of a dataset generated using a conservative orthology inference strategy resulted in a matrix with a high proportion of missing data and moderate to weak support for branching within and placement of Enoplia. A less conservative orthology inference approach recovered more genes and resulted in higher support for the deepest splits within Nematoda, recovering Enoplia as the sister taxon to the rest of Nematoda. Relationships within major clades were similar to those found in previously published studies based on 18S rDNA. Conclusions Expanded transcriptome sequencing of free-living nematodes has contributed to better resolution among deep nematode lineages, though the dataset is still strongly biased toward parasites. Inclusion of more free-living nematodes in future phylogenomic analyses will allow a clearer understanding of many interesting aspects of nematode evolution, such as morphological and molecular adaptations to parasitism and whether nematodes originated in a marine or terrestrial environment. Electronic supplementary material The online version of this article (10.1186/s12862-019-1444-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ashleigh B Smythe
- Department of Biology, Virginia Military Institute, 301B Maury-Brooke Hall, Lexington, VA, 24450, USA
| | - Oleksandr Holovachov
- Department of Zoology, Swedish Museum of Natural History, Box 50007, SE-104 05, Stockholm, Sweden
| | - Kevin M Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Campus Box 870344, Tuscaloosa, AL, 35487, USA.
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Li Y, Kocot KM, Tassia MG, Cannon JT, Bernt M, Halanych KM. Mitogenomics Reveals a Novel Genetic Code in Hemichordata. Genome Biol Evol 2019; 11:29-40. [PMID: 30476024 PMCID: PMC6319601 DOI: 10.1093/gbe/evy254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2018] [Indexed: 01/26/2023] Open
Abstract
The diverse array of codon reassignments demonstrate that the genetic code is not universal in nature. Exploring mechanisms underlying codon reassignment is critical for understanding the evolution of the genetic code during translation. Hemichordata, comprising worm-like Enteropneusta and colonial filter-feeding Pterobranchia, is the sister taxon of echinoderms and is more distantly related to chordates. However, only a few hemichordate mitochondrial genomes have been sequenced, hindering our understanding of mitochondrial genome evolution within Deuterostomia. In this study, we sequenced four mitochondrial genomes and two transcriptomes, including representatives of both major hemichordate lineages and analyzed together with public available data. Contrary to the current understanding of the mitochondrial genetic code in hemichordates, our comparative analyses suggest that UAA encodes Tyr instead of a "Stop" codon in the pterobranch lineage Cephalodiscidae. We also predict that AAA encodes Lys in pterobranch and enteropneust mitochondrial genomes, contradicting the previous assumption that hemichordates share the same genetic code with echinoderms for which AAA encodes Asn. Thus, we propose a new mitochondrial genetic code for Cephalodiscus and a revised code for enteropneusts. Moreover, our phylogenetic analyses are largely consistent with previous phylogenomic studies. The only exception is the phylogenetic position of the enteropneust Stereobalanus, whose placement as sister to all other described enteropneusts. With broader taxonomic sampling, we provide evidence that evolution of mitochondrial gene order and genetic codes in Hemichordata are more dynamic than previously thought and these findings provide insights into mitochondrial genome evolution within this clade.
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Affiliation(s)
- Yuanning Li
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University
| | - Kevin M Kocot
- Department of Biological Sciences & Alabama Museum of Natural History, The University of Alabama
| | - Michael G Tassia
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University
| | - Johanna T Cannon
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara
| | - Matthias Bernt
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Kenneth M Halanych
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University
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Galaska MP, Li Y, Kocot KM, Mahon AR, Halanych KM. Conservation of mitochondrial genome arrangements in brittle stars (Echinodermata, Ophiuroidea). Mol Phylogenet Evol 2018; 130:115-120. [PMID: 30316947 DOI: 10.1016/j.ympev.2018.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022]
Abstract
Brittle stars are conspicuous members of benthic ecosystems, fill many ecological niches and are the most speciose of all classes of echinoderms. With high levels of biodiversity, elucidating the evolutionary history of this group is important. Understanding of higher-level relationships within Ophiuroidea has been aided by multilocus nuclear data and DNA barcoding. However, the degree of consistency between mitochondrial and nuclear data within ophiuroids remains unclear and deserves further assessment. In this study, 17 mitochondrial genomes spanning the taxonomic breadth of Ophiuroidea were utilized to explore evolutionary relationships through maximum likelihood analyses, Bayesian inference and comparative assessment of gene order. Our phylogenetic analyses, based on both nucleotide and amino acid residues, support recent findings based on multilocus nuclear data and morphology, in that the brittle star clades Ophintegrida and Euryophiurida were recovered as monophyletic with the latter comprising Euyalida, Ophiuridae and Ophiopyrgidae. Only three different arrangements of the 13 protein coding and 2 ribosomal RNA genes were observed. As expected, tRNA genes were more likely to have undergone rearrangement but the order of all 37 genes was found to be conserved in all sampled Euryalida and Ophiuridae. Both Euryalida and the clade comprised of Ophiuridae and Ophiopyrgidae, each had their own conserved rearrangement of protein coding genes and ribosomal genes, after divergence from their last common ancestor. Euryalida has a rearrangement of the two ribosomal RNA genes, rrnS and rrnL, in contrast to Ophiuridae and Ophiopyrgidae, which had an inversion of the genes nad1, nad2, and cob relative to Ophintegrida. Further, our data support the gene order found in all sampled Euryalida as the most likely ancestral order for all Ophiuroidea.
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Affiliation(s)
- Matthew P Galaska
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA; Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA.
| | - Yuanning Li
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA
| | - Kevin M Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Andrew R Mahon
- Department of Biology, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Kenneth M Halanych
- Department of Biological Sciences, Auburn University, Molette Biology Laboratory for Environmental and Climate Change Studies, 101 Rouse Life Science Building, Auburn, AL 36849, USA.
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Mikkelsen NT, Kocot KM, Halanych KM. Mitogenomics reveals phylogenetic relationships of caudofoveate aplacophoran molluscs. Mol Phylogenet Evol 2018; 127:429-436. [PMID: 29702218 DOI: 10.1016/j.ympev.2018.04.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 01/16/2018] [Accepted: 04/20/2018] [Indexed: 11/28/2022]
Abstract
The worm-shaped, shell-less aplacophoran molluscs Caudofoveata and Solenogastres have recently received attention as part of the clade Aculifera, but relationships within these two lineages are still largely unknown. Here, we use complete mitochondrial genomes to shed light on higher-level relationships within Caudofoveata. Mitochondrial genomes have been sequenced for many diverse molluscs, but only two mitochondrial genomes from aplacophoran molluscs (the caudofoveates Scutopus ventrolineatus and Chaetoderma nitidulum) are available to date. We sequenced and assembled complete or near complete mitochondrial genomes of five additional species of Caudofoveata (Falcidens acutargatus, Falcidens halanychi, Scutopus robustus, Psilodens balduri and Spathoderma clenchi) and one species of Solenogastres (Neomenia carinata) for comparison to available mitochondrial genomes of aculiferans. Comparison of mitochondrial gene order among different lineages revealed a highly conserved order of protein coding genes corresponding to the hypothesized ancestral gene order for Mollusca. Unique arrangements of tRNAs were found among lineages of aculiferan molluscs as well as among caudofoveate taxa. Phylogenetic analyses of amino acid sequences for the 13 protein-coding genes recovered a monophyletic Aplacophora. Within Caudofoveata, Chaetodermatidae, but not Limifossoridae, was recovered monophyletic. Taken together, our results suggest that mitochondrial genomes can serve as useful molecular markers for aculiferan phylogenetics, especially for more recent phylogenetic events.
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Affiliation(s)
- Nina T Mikkelsen
- University Museum of Bergen, University of Bergen, 5020 Bergen, Norway; Department of Biology, University of Bergen, 5020 Bergen, Norway.
| | - Kevin M Kocot
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA; Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, AL 35487, USA(1)
| | - Kenneth M Halanych
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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Rodriguez J, Jones TH, Sierwald P, Marek PE, Shear WA, Brewer MS, Kocot KM, Bond JE. Step-wise evolution of complex chemical defenses in millipedes: a phylogenomic approach. Sci Rep 2018; 8:3209. [PMID: 29453332 PMCID: PMC5816663 DOI: 10.1038/s41598-018-19996-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/11/2018] [Indexed: 11/19/2022] Open
Abstract
With fossil representatives from the Silurian capable of respiring atmospheric oxygen, millipedes are among the oldest terrestrial animals, and likely the first to acquire diverse and complex chemical defenses against predators. Exploring the origin of complex adaptive traits is critical for understanding the evolution of Earth's biological complexity, and chemical defense evolution serves as an ideal study system. The classic explanation for the evolution of complexity is by gradual increase from simple to complex, passing through intermediate "stepping stone" states. Here we present the first phylogenetic-based study of the evolution of complex chemical defenses in millipedes by generating the largest genomic-based phylogenetic dataset ever assembled for the group. Our phylogenomic results demonstrate that chemical complexity shows a clear pattern of escalation through time. New pathways are added in a stepwise pattern, leading to greater chemical complexity, independently in a number of derived lineages. This complexity gradually increased through time, leading to the advent of three distantly related chemically complex evolutionary lineages, each uniquely characteristic of each of the respective millipede groups.
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Affiliation(s)
- Juanita Rodriguez
- Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA
- CSIRO, Australian National Insect Collection, Canberra, ACT, 2601, Australia
| | - Tappey H Jones
- Department of Chemistry, Virginia Military Institute, Lexington, VA, 24450, USA
| | - Petra Sierwald
- Zoology Department, The Field Museum, Chicago, IL, 60605, USA
| | - Paul E Marek
- Department of Entomology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - William A Shear
- Biology Department, Hampden-Sydney College, Farmville, VA, 23943, USA
| | - Michael S Brewer
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Kevin M Kocot
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Jason E Bond
- Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA.
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Kocot KM, Struck TH, Merkel J, Waits DS, Todt C, Brannock PM, Weese DA, Cannon JT, Moroz LL, Lieb B, Halanych KM. Phylogenomics of Lophotrochozoa with Consideration of Systematic Error. Syst Biol 2018; 66:256-282. [PMID: 27664188 DOI: 10.1093/sysbio/syw079] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/24/2016] [Indexed: 01/13/2023] Open
Abstract
Phylogenomic studies have improved understanding of deep metazoan phylogeny and show promise for resolving incongruences among analyses based on limited numbers of loci. One region of the animal tree that has been especially difficult to resolve, even with phylogenomic approaches, is relationships within Lophotrochozoa (the animal clade that includes molluscs, annelids, and flatworms among others). Lack of resolution in phylogenomic analyses could be due to insufficient phylogenetic signal, limitations in taxon and/or gene sampling, or systematic error. Here, we investigated why lophotrochozoan phylogeny has been such a difficult question to answer by identifying and reducing sources of systematic error. We supplemented existing data with 32 new transcriptomes spanning the diversity of Lophotrochozoa and constructed a new set of Lophotrochozoa-specific core orthologs. Of these, 638 orthologous groups (OGs) passed strict screening for paralogy using a tree-based approach. In order to reduce possible sources of systematic error, we calculated branch-length heterogeneity, evolutionary rate, percent missing data, compositional bias, and saturation for each OG and analyzed increasingly stricter subsets of only the most stringent (best) OGs for these five variables. Principal component analysis of the values for each factor examined for each OG revealed that compositional heterogeneity and average patristic distance contributed most to the variance observed along the first principal component while branch-length heterogeneity and, to a lesser extent, saturation contributed most to the variance observed along the second. Missing data did not strongly contribute to either. Additional sensitivity analyses examined effects of removing taxa with heterogeneous branch lengths, large amounts of missing data, and compositional heterogeneity. Although our analyses do not unambiguously resolve lophotrochozoan phylogeny, we advance the field by reducing the list of viable hypotheses. Moreover, our systematic approach for dissection of phylogenomic data can be applied to explore sources of incongruence and poor support in any phylogenomic data set. [Annelida; Brachiopoda; Bryozoa; Entoprocta; Mollusca; Nemertea; Phoronida; Platyzoa; Polyzoa; Spiralia; Trochozoa.].
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Affiliation(s)
- Kevin M Kocot
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA.,Department of Biological Sciences and Alabama Museum of Natural History, 307 Mary Harmon Bryant Hall, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Torsten H Struck
- Natural History Museum, Department of Research and Collections, University of Oslo, PO Box 1172 Blindern, N-0318 Oslo, Norway
| | - Julia Merkel
- Johannes Gutenberg University, Institute of Zoology, 55099 Mainz, Germany
| | - Damien S Waits
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA
| | - Christiane Todt
- University Museum of Bergen, The Natural History Collections, University of Bergen, Allégaten 41, 5007 Bergen, Norway
| | - Pamela M Brannock
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA
| | - David A Weese
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA.,Department of Biological and Environmental Sciences, Georgia College and State University, Campus Box 81, Milledgeville, GA 31061 USA
| | - Johanna T Cannon
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA.,Department of Zoology, Naturhistoriska riksmuseet, Box 50007, 104 05 Stockholm, Sweden
| | - Leonid L Moroz
- The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St Augustine, FL 32080, USA
| | - Bernhard Lieb
- Johannes Gutenberg University, Institute of Zoology, 55099 Mainz, Germany
| | - Kenneth M Halanych
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, AL 36849, USA
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Whelan NV, Kocot KM, Moroz TP, Mukherjee K, Williams P, Paulay G, Moroz LL, Halanych KM. Author Correction: Ctenophore relationships and their placement as the sister group to all other animals. Nat Ecol Evol 2017; 1:1783. [DOI: 10.1038/s41559-017-0381-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Whelan NV, Kocot KM, Moroz TP, Mukherjee K, Williams P, Paulay G, Moroz LL, Halanych KM. Ctenophore relationships and their placement as the sister group to all other animals. Nat Ecol Evol 2017; 1:1737-1746. [PMID: 28993654 PMCID: PMC5664179 DOI: 10.1038/s41559-017-0331-3] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 08/31/2017] [Indexed: 11/17/2022]
Abstract
Ctenophora, compromising approximately 200 described species, is an important lineage for understanding metazoan evolution and is of great ecological and economic importance. Ctenophore diversity includes species with unique colloblasts used for prey capture, smooth and striated muscles, benthic and pelagic lifestyles, and locomotion with ciliated paddles or muscular propulsion. However, ancestral states of traits are debated and relationships among many lineages are unresolved. Here, using 27 newly sequenced ctenophore transcriptomes, publicly available data, and methods to control systematic error we establish the placement of Ctenophora as the sister group to all other animals and refine phylogenetic relationships within ctenophores. Molecular clock analyses suggest modern ctenophore diversity originated approximately 350MYA ± 88 MY, conflicting with previous hypotheses of approximately 65 MYA. We recover Euplokamis dunlapae, a species with striated muscles, as the sister lineage to other sampled ctenophores. Ancestral state reconstruction shows the most recent common ancestor of extant ctenophores was pelagic, possessed tentacles, was bioluminescent, and did not have separate sexes. Our results imply at least two transitions from a pelagic to a benthic lifestyle within Ctenophora, suggesting such transitions were more common in animal diversification than appreciated.
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Affiliation(s)
- Nathan V Whelan
- Molette Biology Laboratory for Environmental and Climate Change Studies, Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA. .,Warm Springs Fish Technology Center, US Fish and Wildlife Service, 5308 Spring St, Warm Springs, GA, 31830, USA.
| | - Kevin M Kocot
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL, 35487, USA
| | - Tatiana P Moroz
- The Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, FL, 32080, USA
| | - Krishanu Mukherjee
- The Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, FL, 32080, USA
| | - Peter Williams
- The Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, FL, 32080, USA
| | - Gustav Paulay
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | - Leonid L Moroz
- The Whitney Laboratory for Marine Biosciences, University of Florida, St. Augustine, FL, 32080, USA. .,Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL, 32611, USA.
| | - Kenneth M Halanych
- Molette Biology Laboratory for Environmental and Climate Change Studies, Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA.
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Hall MR, Kocot KM, Baughman KW, Fernandez-Valverde SL, Gauthier MEA, Hatleberg WL, Krishnan A, McDougall C, Motti CA, Shoguchi E, Wang T, Xiang X, Zhao M, Bose U, Shinzato C, Hisata K, Fujie M, Kanda M, Cummins SF, Satoh N, Degnan SM, Degnan BM. The crown-of-thorns starfish genome as a guide for biocontrol of this coral reef pest. Nature 2017; 544:231-234. [PMID: 28379940 DOI: 10.1038/nature22033] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 03/05/2017] [Indexed: 01/02/2023]
Abstract
The crown-of-thorns starfish (COTS, the Acanthaster planci species group) is a highly fecund predator of reef-building corals throughout the Indo-Pacific region. COTS population outbreaks cause substantial loss of coral cover, diminishing the integrity and resilience of reef ecosystems. Here we sequenced genomes of COTS from the Great Barrier Reef, Australia and Okinawa, Japan to identify gene products that underlie species-specific communication and could potentially be used in biocontrol strategies. We focused on water-borne chemical plumes released from aggregating COTS, which make the normally sedentary starfish become highly active. Peptide sequences detected in these plumes by mass spectrometry are encoded in the COTS genome and expressed in external tissues. The exoproteome released by aggregating COTS consists largely of signalling factors and hydrolytic enzymes, and includes an expanded and rapidly evolving set of starfish-specific ependymin-related proteins. These secreted proteins may be detected by members of a large family of olfactory-receptor-like G-protein-coupled receptors that are expressed externally, sometimes in a sex-specific manner. This study provides insights into COTS-specific communication that may guide the generation of peptide mimetics for use on reefs with COTS outbreaks.
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Affiliation(s)
- Michael R Hall
- Australian Institute of Marine Science (AIMS), Cape Ferguson, Townsville, Queensland 4810, Australia
| | - Kevin M Kocot
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kenneth W Baughman
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Selene L Fernandez-Valverde
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Marie E A Gauthier
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - William L Hatleberg
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Arunkumar Krishnan
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Carmel McDougall
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Cherie A Motti
- Australian Institute of Marine Science (AIMS), Cape Ferguson, Townsville, Queensland 4810, Australia
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Tianfang Wang
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
| | - Xueyan Xiang
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Min Zhao
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
| | - Utpal Bose
- Australian Institute of Marine Science (AIMS), Cape Ferguson, Townsville, Queensland 4810, Australia.,Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
| | - Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Kanako Hisata
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Manabu Fujie
- DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Miyuki Kanda
- DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Scott F Cummins
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Sandie M Degnan
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bernard M Degnan
- Centre for Marine Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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32
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Tanner AR, Fuchs D, Winkelmann IE, Gilbert MTP, Pankey MS, Ribeiro ÂM, Kocot KM, Halanych KM, Oakley TH, da Fonseca RR, Pisani D, Vinther J. Molecular clocks indicate turnover and diversification of modern coleoid cephalopods during the Mesozoic Marine Revolution. Proc Biol Sci 2017; 284:20162818. [PMID: 28250188 PMCID: PMC5360930 DOI: 10.1098/rspb.2016.2818] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/08/2017] [Indexed: 11/12/2022] Open
Abstract
Coleoid cephalopod molluscs comprise squid, cuttlefish and octopuses, and represent nearly the entire diversity of modern cephalopods. Sophisticated adaptations such as the use of colour for camouflage and communication, jet propulsion and the ink sac highlight the unique nature of the group. Despite these striking adaptations, there are clear parallels in ecology between coleoids and bony fishes. The coleoid fossil record is limited, however, hindering confident analysis of the tempo and pattern of their evolution. Here we use a molecular dataset (180 genes, approx. 36 000 amino acids) of 26 cephalopod species to explore the phylogeny and timing of cephalopod evolution. We show that crown cephalopods diverged in the Silurian-Devonian, while crown coleoids had origins in the latest Palaeozoic. While the deep-sea vampire squid and dumbo octopuses have ancient origins extending to the Early Mesozoic Era, 242 ± 38 Ma, incirrate octopuses and the decabrachian coleoids (10-armed squid) diversified in the Jurassic Period. These divergence estimates highlight the modern diversity of coleoid cephalopods emerging in the Mesozoic Marine Revolution, a period that also witnessed the radiation of most ray-finned fish groups in addition to several other marine vertebrates. This suggests that that the origin of modern cephalopod biodiversity was contingent on ecological competition with marine vertebrates.
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Affiliation(s)
- Alastair R Tanner
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Dirk Fuchs
- Earth and Planetary System Science, Department of Natural History Sciences, Hokkaido University, Sapporo, Japan
| | - Inger E Winkelmann
- Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - M Thomas P Gilbert
- Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
- Trace and Environmental DNA Laboratory, Department of Environment and Agriculture, Curtin University, Perth, Western Australia, Australia
- NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway
| | - M Sabrina Pankey
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Ângela M Ribeiro
- Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - Kevin M Kocot
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL 35487, USA
| | - Kenneth M Halanych
- Department of Biological Sciences, Auburn University, Auburn, AL 36830, USA
| | - Todd H Oakley
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Rute R da Fonseca
- Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Davide Pisani
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Jakob Vinther
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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Stöger I, Kocot KM, Poustka AJ, Wilson NG, Ivanov D, Halanych KM, Schrödl M. Monoplacophoran mitochondrial genomes: convergent gene arrangements and little phylogenetic signal. BMC Evol Biol 2016; 16:274. [PMID: 27986078 PMCID: PMC5162086 DOI: 10.1186/s12862-016-0829-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/17/2016] [Indexed: 04/07/2023] Open
Abstract
BACKGROUND Although recent studies have greatly advanced understanding of deep molluscan phylogeny, placement of some taxa remains uncertain as different datasets support competing class-relationships. Traditionally, morphologists have placed Monoplacophora, a group of morphologically simple, limpet-like molluscs as sister group to all other conchiferans (shelled molluscs other than Polyplacophora), a grouping that is supported by the latest large-scale phylogenomic study that includes Laevipilina. However, molecular datasets dominated by nuclear ribosomal genes support Monoplacophora + Polyplacophora (Serialia). Here, we evaluate the potential of mitochondrial genome data for resolving placement of Monoplacophora. RESULTS Two complete (Laevipilina antarctica and Vema ewingi) and one partial (Laevipilina hyalina) mitochondrial genomes were sequenced, assembled, and compared. All three genomes show a highly similar architecture including an unusually high number of non-coding regions. Comparison of monoplacophoran gene order shows a gene arrangement pattern not previously reported; there is an inversion of one large gene cluster. Our reanalyses of recently published polyplacophoran mitogenomes show, however, that this feature is also present in some chiton species. Maximum Likelihood and Bayesian Inference analyses of 13 mitochondrial protein-coding genes failed to robustly place Monoplacophora and hypothesis testing could not reject any of the evaluated placements of Monoplacophora. CONCLUSIONS Under both serialian or aculiferan-conchiferan scenarios, the observed gene cluster inversion appears to be a convergent evolution of gene arrangements in molluscs. Our phylogenetic results are inconclusive and sensitive to taxon sampling. Aculifera (Polyplacophora + Aplacophora) and Conchifera were never recovered. However, some analyses recovered Serialia (Monoplacophora + Polyplacophora), Diasoma (Bivalvia + Scaphopoda) or Pleistomollusca (Bivalvia + Gastropoda). Although we could not shed light on deep evolutionary traits of Mollusca we found unique patterns of gene arrangements that are common to monoplacophoran and chitonine polyplacophoran species but not to acanthochitonine Polyplacophora. Complete mitochondrial genome of Laevipilina antarctica.
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Affiliation(s)
- I Stöger
- SNSB-Bavarian State Collection of Zoology, Muenchhausenstrasse 21, 81247, Munich, Germany.
| | - K M Kocot
- Department of Biological Sciences, University of Alabama, Box 870344, Tuscaloosa, AL, 35487, USA
| | - A J Poustka
- Max-Planck Institut fuer Molekulare Genetik, Evolution and Development Group, Ihnestrasse 73, 14195, Berlin, Germany.,Dahlem Center for Genome Research and Medical Systems Biology, Environmental and Phylogenomics Group, Fabeckstraße 60-62, 14195, Berlin, Germany.,Alacris Theranostics GmbH, Fabeckstr. 60-62, 14195, Berlin, Germany
| | - N G Wilson
- Western Australian Museum, Aquatic Zoology/Molecular Systematics Unit, 49 Kew Street, Welshpool, WA, 6106, Australia
| | - D Ivanov
- Zoological Museum, Moscow State University, Bolshaya Nikitskaya Str. 6, 225009, Moscow, Russia
| | - K M Halanych
- Biological Sciences Department, Auburn University, Life Sciences Bld. 101, Auburn, AL, 36849, USA
| | - M Schrödl
- SNSB-Bavarian State Collection of Zoology, Muenchhausenstrasse 21, 81247, Munich, Germany.,Faculty of Biology, Department II, Ludwig-Maximilians-Universitaet Muenchen, Großhaderner Strasse 2-4, 82152, Planegg-Martinsried, Germany.,GeoBio-Center at LMU, Richard-Wagner-Strasse 10, 80333, Munich, Germany
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Li Y, Kocot KM, Whelan NV, Santos SR, Waits DS, Thornhill DJ, Halanych KM. Phylogenomics of tubeworms (Siboglinidae, Annelida) and comparative performance of different reconstruction methods. ZOOL SCR 2016. [DOI: 10.1111/zsc.12201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Yuanning Li
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
| | - Kevin M. Kocot
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
- Department of Biological Sciences & Alabama Museum of Natural History The University of Alabama 35847 Tuscaloosa AL USA
| | - Nathan V. Whelan
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
| | - Scott R. Santos
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
| | - Damien S. Waits
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
| | - Daniel J. Thornhill
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
| | - Kenneth M. Halanych
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University 36830 Auburn AL USA
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Kocot KM, Aguilera F, McDougall C, Jackson DJ, Degnan BM. Sea shell diversity and rapidly evolving secretomes: insights into the evolution of biomineralization. Front Zool 2016; 13:23. [PMID: 27279892 PMCID: PMC4897951 DOI: 10.1186/s12983-016-0155-z] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/27/2016] [Indexed: 12/21/2022] Open
Abstract
An external skeleton is an essential part of the body plan of many animals and is thought to be one of the key factors that enabled the great expansion in animal diversity and disparity during the Cambrian explosion. Molluscs are considered ideal to study the evolution of biomineralization because of their diversity of highly complex, robust and patterned shells. The molluscan shell forms externally at the interface of animal and environment, and involves controlled deposition of calcium carbonate within a framework of macromolecules that are secreted from the dorsal mantle epithelium. Despite its deep conservation within Mollusca, the mantle is capable of producing an incredible diversity of shell patterns, and macro- and micro-architectures. Here we review recent developments within the field of molluscan biomineralization, focusing on the genes expressed in the mantle that encode secreted proteins. The so-called mantle secretome appears to regulate shell deposition and patterning and in some cases becomes part of the shell matrix. Recent transcriptomic and proteomic studies have revealed marked differences in the mantle secretomes of even closely-related molluscs; these typically exceed expected differences based on characteristics of the external shell. All mantle secretomes surveyed to date include novel genes encoding lineage-restricted proteins and unique combinations of co-opted ancient genes. A surprisingly large proportion of both ancient and novel secreted proteins containing simple repetitive motifs or domains that are often modular in construction. These repetitive low complexity domains (RLCDs) appear to further promote the evolvability of the mantle secretome, resulting in domain shuffling, expansion and loss. RLCD families further evolve via slippage and other mechanisms associated with repetitive sequences. As analogous types of secreted proteins are expressed in biomineralizing tissues in other animals, insights into the evolution of the genes underlying molluscan shell formation may be applied more broadly to understanding the evolution of metazoan biomineralization.
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Affiliation(s)
- Kevin M Kocot
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072 Australia.,Current address: Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, Alabama 35487 USA
| | - Felipe Aguilera
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072 Australia.,Current address: Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, Bergen, 5008 Norway
| | - Carmel McDougall
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072 Australia
| | - Daniel J Jackson
- Department of Geobiology, Goldschmidtstr.3, Georg-August University of Göttingen, 37077 Göttingen, Germany
| | - Bernard M Degnan
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072 Australia
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Garrison NL, Rodriguez J, Agnarsson I, Coddington JA, Griswold CE, Hamilton CA, Hedin M, Kocot KM, Ledford JM, Bond JE. Spider phylogenomics: untangling the Spider Tree of Life. PeerJ 2016; 4:e1719. [PMID: 26925338 PMCID: PMC4768681 DOI: 10.7717/peerj.1719] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 01/31/2016] [Indexed: 12/12/2022] Open
Abstract
Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the "usual suspect" genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125-90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs.
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Affiliation(s)
- Nicole L. Garrison
- Department of Biological Sciences and Auburn University Museum of Natural History, Auburn University, Auburn, AL, United States
| | - Juanita Rodriguez
- Department of Biological Sciences and Auburn University Museum of Natural History, Auburn University, Auburn, AL, United States
| | - Ingi Agnarsson
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Jonathan A. Coddington
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washingtion, DC, United States
| | - Charles E. Griswold
- Arachnology, California Academy of Sciences, San Francisco, CA, United States
| | - Christopher A. Hamilton
- Department of Biological Sciences and Auburn University Museum of Natural History, Auburn University, Auburn, AL, United States
| | - Marshal Hedin
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, University of Alabama—Tuscaloosa, Tuscaloosa, AL, United States
| | - Joel M. Ledford
- Department of Plant Biology, University of California, Davis, Davis, CA, United States
| | - Jason E. Bond
- Department of Biological Sciences and Auburn University Museum of Natural History, Auburn University, Auburn, AL, United States
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Whelan NV, Kocot KM, Halanych KM. Employing Phylogenomics to Resolve the Relationships among Cnidarians, Ctenophores, Sponges, Placozoans, and Bilaterians. Integr Comp Biol 2015; 55:1084-95. [PMID: 25972566 DOI: 10.1093/icb/icv037] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Despite an explosion in the amount of sequence data, phylogenomics has failed to settle controversy regarding some critical nodes on the animal tree of life. Understanding relationships among Bilateria, Ctenophora, Cnidaria, Placozoa, and Porifera is essential for studying how complex traits such as neurons, muscles, and gastrulation have evolved. Recent studies have cast doubt on the historical viewpoint that sponges are sister to all other animal lineages with recent studies recovering ctenophores as sister. However, the ctenophore-sister hypothesis has been criticized as unrealistic and caused by systematic error. We review past phylogenomic studies and potential causes of systematic error in an effort to identify areas that can be improved in future studies. Increased sampling of taxa, less missing data, and a priori removal of sequences and taxa that may cause systematic error in phylogenomic inference will likely be the most fruitful areas of focus when assembling future datasets. Ultimately, we foresee metazoan relationships being resolved with higher support in the near future, and we caution against dismissing novel hypotheses merely because they conflict with historical viewpoints of animal evolution.
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Affiliation(s)
- Nathan V Whelan
- *Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, 101 Life Sciences Building, Auburn, AL 36849, USA;
| | - Kevin M Kocot
- School of Biological Sciences, The University of Queensland, 325 Goddard Building, St Lucia, QLD 4101, Australia
| | - Kenneth M Halanych
- *Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, 101 Life Sciences Building, Auburn, AL 36849, USA
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Havird JC, Kocot KM, Brannock PM, Cannon JT, Waits DS, Weese DA, Santos SR, Halanych KM. Reconstruction of cyclooxygenase evolution in animals suggests variable, lineage-specific duplications, and homologs with low sequence identity. J Mol Evol 2015; 80:193-208. [PMID: 25758350 DOI: 10.1007/s00239-015-9670-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/02/2015] [Indexed: 11/30/2022]
Abstract
Cyclooxygenase (COX) enzymatically converts arachidonic acid into prostaglandin G/H in animals and has importance during pregnancy, digestion, and other physiological functions in mammals. COX genes have mainly been described from vertebrates, where gene duplications are common, but few studies have examined COX in invertebrates. Given the increasing ease in generating genomic data, as well as recent, although incomplete descriptions of potential COX sequences in Mollusca, Crustacea, and Insecta, assessing COX evolution across Metazoa is now possible. Here, we recover 40 putative COX orthologs by searching publicly available genomic resources as well as ~250 novel invertebrate transcriptomic datasets. Results suggest the common ancestor of Cnidaria and Bilateria possessed a COX homolog similar to those of vertebrates, although such homologs were not found in poriferan and ctenophore genomes. COX was found in most crustaceans and the majority of molluscs examined, but only specific taxa/lineages within Cnidaria and Annelida. For example, all octocorallians appear to have COX, while no COX homologs were found in hexacorallian datasets. Most species examined had a single homolog, although species-specific COX duplications were found in members of Annelida, Mollusca, and Cnidaria. Additionally, COX genes were not found in Hemichordata, Echinodermata, or Platyhelminthes, and the few previously described COX genes in Insecta lacked appreciable sequence homology (although structural analyses suggest these may still be functional COX enzymes). This analysis provides a benchmark for identifying COX homologs in future genomic and transcriptomic datasets, and identifies lineages for future studies of COX.
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Affiliation(s)
- Justin C Havird
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, USA,
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Abstract
Nemerteans are one of few animal groups that have evolved the ability to utilize toxins for both defense and subduing prey, but little is known about specific nemertean toxins. In particular, no study has identified specific toxin genes even though peptide toxins are known from some nemertean species. Information about toxin genes is needed to better understand evolution of toxins across animals and possibly provide novel targets for pharmaceutical and industrial applications. We sequenced and annotated transcriptomes of two free-living and one commensal nemertean and annotated an additional six publicly available nemertean transcriptomes to identify putative toxin genes. Approximately 63–74% of predicted open reading frames in each transcriptome were annotated with gene names, and all species had similar percentages of transcripts annotated with each higher-level GO term. Every nemertean analyzed possessed genes with high sequence similarities to known animal toxins including those from stonefish, cephalopods, and sea anemones. One toxin-like gene found in all nemerteans analyzed had high sequence similarity to Plancitoxin-1, a DNase II hepatotoxin that may function well at low pH, which suggests that the acidic body walls of some nemerteans could work to enhance the efficacy of protein toxins. The highest number of toxin-like genes found in any one species was seven and the lowest was three. The diversity of toxin-like nemertean genes found here is greater than previously documented, and these animals are likely an ideal system for exploring toxin evolution and industrial applications of toxins.
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Affiliation(s)
- Nathan V Whelan
- Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, Alabama
| | - Kevin M Kocot
- Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, Alabama Present address: School of Biological Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Scott R Santos
- Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, Alabama
| | - Kenneth M Halanych
- Department of Biological Sciences, Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, Alabama
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Cannon JT, Kocot KM, Waits DS, Weese DA, Swalla BJ, Santos SR, Halanych KM. Phylogenomic resolution of the hemichordate and echinoderm clade. Curr Biol 2014; 24:2827-32. [PMID: 25454590 DOI: 10.1016/j.cub.2014.10.016] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 02/01/2023]
Abstract
Ambulacraria, comprising Hemichordata and Echinodermata, is closely related to Chordata, making it integral to understanding chordate origins and polarizing chordate molecular and morphological characters. Unfortunately, relationships within Hemichordata and Echinodermata have remained unresolved, compromising our ability to extrapolate findings from the most closely related molecular and developmental models outside of Chordata (e.g., the acorn worms Saccoglossus kowalevskii and Ptychodera flava and the sea urchin Strongylocentrotus purpuratus). To resolve long-standing phylogenetic issues within Ambulacraria, we sequenced transcriptomes for 14 hemichordates as well as 8 echinoderms and complemented these with existing data for a total of 33 ambulacrarian operational taxonomic units (OTUs). Examination of leaf stability values revealed rhabdopleurid pterobranchs and the enteropneust Stereobalanus canadensis were unstable in placement; therefore, analyses were also run without these taxa. Analyses of 185 genes resulted in reciprocal monophyly of Enteropneusta and Pterobranchia, placed the deep-sea family Torquaratoridae within Ptychoderidae, and confirmed the position of ophiuroid brittle stars as sister to asteroid sea stars (the Asterozoa hypothesis). These results are consistent with earlier perspectives concerning plesiomorphies of Ambulacraria, including pharyngeal gill slits, a single axocoel, and paired hydrocoels and somatocoels. The resolved ambulacrarian phylogeny will help clarify the early evolution of chordate characteristics and has implications for our understanding of major fossil groups, including graptolites and somasteroideans.
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Affiliation(s)
- Johanna T Cannon
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA; Department of Zoology, Naturhistoriska Riksmuseet, 104 05 Stockholm, Sweden; Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA.
| | - Kevin M Kocot
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA; School of Biological Sciences, University of Queensland, Brisbane, QLD 4072, Australia; Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA
| | - Damien S Waits
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA
| | - David A Weese
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA; Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, GA 31061, USA
| | - Billie J Swalla
- Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA
| | - Scott R Santos
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA
| | - Kenneth M Halanych
- Department of Biological Sciences and Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, AL 36849, USA; Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA.
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Halanych KM, Kocot KM. Repurposed transcriptomic data facilitate discovery of innate immunity toll-like receptor (TLR) Genes across Lophotrochozoa. Biol Bull 2014; 227:201-9. [PMID: 25411377 DOI: 10.1086/bblv227n2p201] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The growing volume of genomic data from across life represents opportunities for deriving valuable biological information from data that were initially collected for another purpose. Here, we use transcriptomes collected for phylogenomic studies to search for toll-like receptor (TLR) genes in poorly sampled lophotrochozoan clades (Annelida, Mollusca, Brachiopoda, Phoronida, and Entoprocta) and one ecdysozoan clade (Priapulida). TLR genes are involved in innate immunity across animals by recognizing potential microbial infection. They have an extracellular leucine-rich repeat (LRR) domain connected to a transmembrane domain and an intracellular toll/interleukin-1 receptor (TIR) domain. Consequently, these genes are important in initiating a signaling pathway to trigger defense. We found at least one TLR ortholog in all but two taxa examined, suggesting that a broad array of lophotrochozoans may have innate immune systems similar to those observed in vertebrates and arthropods. Comparison to the SMART database confirmed the presence of both the LRR and the TIR protein motifs characteristic of TLR genes. Because we looked at only one transcriptome per species, discovery of TLR genes was limited for most taxa. However, several TRL-like genes that vary in the number and placement of LRR domains were found in phoronids. Additionally, several contigs contained LRR domains but lacked TIR domains, suggesting they were not TLRs. Many of these LRR-containing contigs had other domains (e.g., immunoglobin) and are likely involved in innate immunity.
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Affiliation(s)
- Kenneth M Halanych
- 101 Rouse Life Sciences Building, Department of Biological Sciences, Auburn University, Auburn, Alabama 36849; and
| | - Kevin M Kocot
- 101 Rouse Life Sciences Building, Department of Biological Sciences, Auburn University, Auburn, Alabama 36849; and 325 Goddard Building 8, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4067, Australia
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Doty KF, Betzelberger AM, Kocot KM, Cook ME. Immunofluorescence localization of the tubulin cytoskeleton during cell division and cell growth in members of the Coleochaetales (Streptophyta). J Phycol 2014; 50:624-39. [PMID: 26988447 DOI: 10.1111/jpy.12194] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 04/09/2014] [Indexed: 05/24/2023]
Abstract
Study of charophycean green algae, including the Coleochaetales, may shed light on the evolutionary history of characters they share with their land plant relatives. We examined the tubulin cytoskeleton during mitosis, cytokinesis, and growth in members of the Coleochaetales with diverse morphologies to determine if phragmoplasts occurred throughout this order and to identify microtubular patterns associated with cell growth. Species representing three subgroups of Coleochaete and its sister genus Chaetosphaeridium were studied. Cytokinesis involving a phragmoplast was found in the four taxa examined. Differential interference contrast microscopy of living cells confirmed that polar cytokinesis like that described in the model flowering plant Arabidopsis occurred in all species when the forming cell plate traversed a vacuole. Calcofluor labeling of cell walls demonstrated directed growth from particular cell regions of all taxa. Electron microscopy confirmed directed growth in the unusual growth pattern of Chaetosphaeridium. All four species exhibited unordered microtubule patterns associated with diffuse growth in early cell expansion. In subsequent elongating cells, Coleochaete irregularis Pringsheim and Chaetosphaeridium globosum (Nordstedt) Klebahn exhibited tubulin cytoskeleton arrays corresponding to growth patterns associated with tip growth in plants, fungi, and other charophycean algae. Hoop-shaped microtubules frequently associated with diffuse growth of elongating cells in plants were not observed in any of these species. Presence of phragmoplasts in the diverse species studied supports the hypothesis that cytokinesis involving a phragmoplast originated in a common ancestor of the Coleochaetales, and possibly in a common ancestor of Charales, Coleochaetales, Zygnematales, and plants.
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Affiliation(s)
- Karen F Doty
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, Illinois, 61790-4120, USA
| | - Amy M Betzelberger
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, Illinois, 61790-4120, USA
| | - Kevin M Kocot
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, Illinois, 61790-4120, USA
| | - Martha E Cook
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, Illinois, 61790-4120, USA
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Kocot KM, Halanych KM, Krug PJ. Phylogenomics supports Panpulmonata: Opisthobranch paraphyly and key evolutionary steps in a major radiation of gastropod molluscs. Mol Phylogenet Evol 2013; 69:764-71. [DOI: 10.1016/j.ympev.2013.07.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 06/11/2013] [Accepted: 07/01/2013] [Indexed: 12/17/2022]
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Kocot KM, Citarella MR, Moroz LL, Halanych KM. PhyloTreePruner: A Phylogenetic Tree-Based Approach for Selection of Orthologous Sequences for Phylogenomics. Evol Bioinform Online 2013; 9:429-35. [PMID: 24250218 PMCID: PMC3825643 DOI: 10.4137/ebo.s12813] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Molecular phylogenetics relies on accurate identification of orthologous sequences among the taxa of interest. Most orthology inference programs available for use in phylogenomics rely on small sets of pre-defined orthologs from model organisms or phenetic approaches such as all-versus-all sequence comparisons followed by Markov graph-based clustering. Such approaches have high sensitivity but may erroneously include paralogous sequences. We developed PhyloTreePruner, a software utility that uses a phylogenetic approach to refine orthology inferences made using phenetic methods. PhyloTreePruner checks single-gene trees for evidence of paralogy and generates a new alignment for each group containing only sequences inferred to be orthologs. Importantly, PhyloTreePruner takes into account support values on the tree and avoids unnecessarily deleting sequences in cases where a weakly supported tree topology incorrectly indicates paralogy. A test of PhyloTreePruner on a dataset generated from 11 completely sequenced arthropod genomes identified 2,027 orthologous groups sampled for all taxa. Phylogenetic analysis of the concatenated supermatrix yielded a generally well-supported topology that was consistent with the current understanding of arthropod phylogeny. PhyloTreePruner is freely available from http://sourceforge.net/projects/phylotreepruner/.
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Affiliation(s)
- Kevin M Kocot
- Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, USA
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Abstract
Phylogenetic relationships and identifications in the aplacophoran taxon Solenogastres (Neomeniomorpha) are in flux largely because descriptions of hard parts--sclerites, radulae, copulatory spicules--and body shape have often not been adequately illustrated or utilized. With easily recognizable and accessible hard parts, descriptions of Solenogastres are of greater use, not just to solenogaster taxonomists, but also to ecologists, paleontologists, and evolutionary biologists. Phylogenetic studies of Aplacophora, Mollusca, and the Lophotrochozoa as a whole, whether morphological or molecular, would be enhanced. As an example, morphologic characters, both isolated hard parts and internal anatomy, are provided for two genera in the Dondersiidae. Five species are described or redescribed and earlier descriptions corrected and enhanced. Three belong to Dondersia: D. festiva Hubrecht, D. incali (Scheltema), and D. namibiensis n. sp., the latter differentiated unambiguously from D. incali only by sclerites and copulatory spicules. Two species belong to Lyratoherpia: L. carinata Salvini-Plawen and L. californica (Heath). Notes are given for other species in Dondersiidae: L. bracteata Salvini-Plawen, Ichthyomenia ichthyodes (Pruvot), and Heathia porosa (Heath). D. indica Stork is synonymized with D. annulata. A cladistic morphological analysis was conducted to examine the utility of hard parts for reconstructing solenogaster phylogeny. Results indicate monophyly of Dondersia and Lyratoherpia as described here.
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Affiliation(s)
- Amélie H Scheltema
- Woods Hole Oceanographic Institution, Biology Dept., Woods Hole, MA 02543, USA.
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Pierce SK, Fang X, Schwartz JA, Jiang X, Zhao W, Curtis NE, Kocot KM, Yang B, Wang J. Transcriptomic evidence for the expression of horizontally transferred algal nuclear genes in the photosynthetic sea slug, Elysia chlorotica. Mol Biol Evol 2011; 29:1545-56. [PMID: 22319135 DOI: 10.1093/molbev/msr316] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Analysis of the transcriptome of the kleptoplastic sea slug, Elysia chlorotica, has revealed the presence of at least 101 chloroplast-encoded gene sequences and 111 transcripts matching 52 nuclear-encoded genes from the chloroplast donor, Vaucheria litorea. These data clearly show that the symbiotic chloroplasts are translationally active and, of even more interest, that a variety of functional algal genes have been transferred into the slug genome, as has been suggested by earlier indirect experiments. Both the chloroplast- and nuclear-encoded sequences were rare within the E. chlorotica transcriptome, suggesting that their copy numbers and synthesis rates are low, and required both a large amount of sequence data and native algal sequences to find. These results show that the symbiotic chloroplasts residing inside the host molluscan cell are maintained by an interaction of both organellar and host biochemistry directed by the presence of transferred genes.
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Affiliation(s)
- Sidney K Pierce
- Department of Integrative Biology, University of South Florida, USA.
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Kohn AB, Citarella MR, Kocot KM, Bobkova YV, Halanych KM, Moroz LL. Rapid evolution of the compact and unusual mitochondrial genome in the ctenophore, Pleurobrachia bachei. Mol Phylogenet Evol 2011; 63:203-7. [PMID: 22201557 DOI: 10.1016/j.ympev.2011.12.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/05/2011] [Accepted: 12/07/2011] [Indexed: 12/29/2022]
Abstract
Ctenophores are one of the most basally branching lineages of metazoans with the largest mitochondrial organelles in the animal kingdom. We sequenced the mitochondrial (mtDNA) genome from the Pacific cidipid ctenophore, Pleurobrachia bachei. The circular mitochondrial genome is 11,016 nts, with only 12 genes, and one of the smallest metazoan mtDNA genomes recorded. The protein coding genes are intronless cox1-3, cob, nad1, 3, 4, 4L and 5. The nad2 and 6 genes are represented as short fragments whereas the atp6 gene was found in the nuclear genome. Only the large ribosomal RNA subunit and two tRNAs were present with possibly the small subunit unidentifiable due to extensive fragmentation. The observed unique features of this mitochondrial genome suggest that nuclear and mitochondrial genomes have evolved at very different rates. This reduced mtDNA genome sharply contrasts with the very large sizes of mtDNA found in other basal metazoans including Porifera (sponges), and Placozoa (Trichoplax).
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Affiliation(s)
- Andrea B Kohn
- The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
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