1
|
Stick R, Peter A. CaaX-less lamins: Lophotrochozoa provide a glance at the playground of evolution. PROTOPLASMA 2023; 260:741-756. [PMID: 36102949 PMCID: PMC10125929 DOI: 10.1007/s00709-022-01809-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/01/2022] [Indexed: 05/05/2023]
Abstract
Nuclear lamins are the main components of the nuclear lamina in many eukaryotes. They are members of the intermediate filament (IF) protein family. Lamins differ from cytoplasmic IF proteins by the presence of a nuclear localisation sequence (NLS) and a C-terminal tetrapeptide, the CaaX motif. The CaaX motif is target of post-translational modifications including isoprenylation, proteolytic processing, and carboxyl-methylation. These modifications, in conjunction with the NLS, direct lamins to the inner nuclear membrane where they assemble into filaments. Lamins lacking a CaaX motif are unable to associate independently with nuclear membranes and remain in the nucleoplasm. So far, three species have been reported to exclusively express CaaX-less lamins. All three belong to the lophotrochozoan lineage. To find out whether they represent rare exceptions, we analysed lamins of representatives of 17 lophotrochozoan phyla. Here we report that all four clades of Rotifera as well as individual taxa of Mollusca and Annelida lack CaaX-lamins, but express lamins with alternative C-termini. Of note, the respective mollusc and annelid groups occupy very different phylogenetic ranks. Most of these alternative C-termini are rich in aromatic residues. A possible function of these residues in membrane association is discussed. Alternative splicing of terebellid lamin transcripts gives rise to two lamin variants, one with a CaaX motif and one with an alternative C-terminus. A similar situation is found in Arenicolidae, Opheliidae, Capitellidae, and Echiura. This points a way, how the switch from lamins carrying a CaaX motif to lamins with alternative C-termini may have occurred.
Collapse
Affiliation(s)
- Reimer Stick
- Department of Cell Biology, University of Bremen, P.O. Box 330440, 28334, Bremen, Germany.
| | - Annette Peter
- Department of Cell Biology, University of Bremen, P.O. Box 330440, 28334, Bremen, Germany
| |
Collapse
|
2
|
Zhao TY, Yang RJ, Lü L, Ru SS, Wayland MT, Chen HX, Li YH, Li L. Phylomitogenomic Analyses Provided Further Evidence for the Resurrection of the Family Pseudoacanthocephalidae (Acanthocephala: Echinorhynchida). Animals (Basel) 2023; 13:ani13071256. [PMID: 37048513 PMCID: PMC10093747 DOI: 10.3390/ani13071256] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/20/2023] [Accepted: 03/29/2023] [Indexed: 04/14/2023] Open
Abstract
The phylum Acanthocephala is an important monophyletic group of parasites, with adults parasitic in the digestive tracts of all major vertebrate groups. Acanthocephalans are of veterinary, medical, and economic importance due to their ability to cause disease in domestic animals, wildlife, and humans. However, the current genetic data for acanthocephalans are sparse, both in terms of the proportion of taxa surveyed and the number of genes sequenced. Consequently, the basic molecular phylogenetic framework for the phylum is still incomplete. In the present study, we reported the first complete mitochondrial genome from a representative of the family Pseudoacanthocephalidae Petrochenko, 1956. The mitogenome of Pseudoacanthocephalus bufonis (Shipley, 1903) is 14,056 bp in length, contains 36 genes (12 protein-coding genes (PCGs) (lacking atp8), 22 tRNA genes, and 2 rRNA genes (rrnL and rrnS)) and two non-coding regions (NCR1 and NCR2), and displayed the highest GC-skew in the order Echinorhynchida. Phylogenetic results of maximum likelihood (ML) and Bayesian inference (BI) using the amino acid sequences of 12 protein-coding genes in different models provided further evidence for the resurrection of the family Pseudoacanthocephalidae and also supported that the order Echinorhynchida is paraphyletic. A monophyletic clade comprising P. bufonis and Cavisoma magnum suggests a close affinity between Pseudoacanthocephalidae and Cavisomatidae. Our phylogenetic analyses also showed that Polymorphidae has a closer relationship with Centrorhynchidae than Plagiorhynchidae in the monophyletic order Polymorphida.
Collapse
Affiliation(s)
- Tian-You Zhao
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| | - Rui-Jia Yang
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| | - Liang Lü
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| | - Si-Si Ru
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| | | | - Hui-Xia Chen
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| | - Yuan-Hao Li
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Liang Li
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline Cell Biology, Shijiazhuang 050024, China
| |
Collapse
|
3
|
Mauer KM, Schmidt H, Dittrich M, Fröbius AC, Hellmann SL, Zischler H, Hankeln T, Herlyn H. Genomics and transcriptomics of epizoic Seisonidea (Rotifera, syn. Syndermata) reveal strain formation and gradual gene loss with growing ties to the host. BMC Genomics 2021; 22:604. [PMID: 34372786 PMCID: PMC8351084 DOI: 10.1186/s12864-021-07857-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/28/2021] [Indexed: 11/20/2022] Open
Abstract
Background Seisonidea (also Seisonacea or Seisonidae) is a group of small animals living on marine crustaceans (Nebalia spec.) with only four species described so far. Its monophyletic origin with mostly free-living wheel animals (Monogononta, Bdelloidea) and endoparasitic thorny-headed worms (Acanthocephala) is widely accepted. However, the phylogenetic relationships inside the Rotifera-Acanthocephala clade (Rotifera sensulato or Syndermata) are subject to ongoing debate, with consequences for our understanding of how genomes and lifestyles might have evolved. To gain new insights, we analyzed first drafts of the genome and transcriptome of the key taxon Seisonidea. Results Analyses of gDNA-Seq and mRNA-Seq data uncovered two genetically distinct lineages in Seison nebaliae Grube, 1861 off the French Channel coast. Their mitochondrial haplotypes shared only 82% sequence identity despite identical gene order. In the nuclear genome, distinct linages were reflected in different gene compactness, GC content and codon usage. The haploid nuclear genome spans ca. 46 Mb, of which 96% were reconstructed. According to ~ 23,000 SuperTranscripts, gene number in S. nebaliae should be within the range published for other members of Rotifera-Acanthocephala. Consistent with this, numbers of metazoan core orthologues and ANTP-type transcriptional regulatory genes in the S. nebaliae genome assembly were between the corresponding numbers in the other assemblies analyzed. We additionally provide evidence that a basal branching of Seisonidea within Rotifera-Acanthocephala could reflect attraction to the outgroup. Accordingly, rooting via a reconstructed ancestral sequence led to monophyletic Pararotatoria (Seisonidea+Acanthocephala) within Hemirotifera (Bdelloidea+Pararotatoria). Conclusion Matching genome/transcriptome metrics with the above phylogenetic hypothesis suggests that a haploid nuclear genome of about 50 Mb represents the plesiomorphic state for Rotifera-Acanthocephala. Smaller genome size in S. nebaliae probably results from subsequent reduction. In contrast, genome size should have increased independently in monogononts as well as bdelloid and acanthocephalan stem lines. The present data additionally indicate a decrease in gene repertoire from free-living to epizoic and endoparasitic lifestyles. Potentially, this reflects corresponding steps from the root of Rotifera-Acanthocephala via the last common ancestors of Hemirotifera and Pararotatoria to the one of Acanthocephala. Lastly, rooting via a reconstructed ancestral sequence may prove useful in phylogenetic analyses of other deep splits. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07857-y.
Collapse
Affiliation(s)
- Katharina M Mauer
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Hanno Schmidt
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Marco Dittrich
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Andreas C Fröbius
- Molecular Andrology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Gießen, Giessen, Germany
| | - Sören Lukas Hellmann
- Institute of Organismic and Molecular Evolution (iomE), Molecular Genetics and Genomic Analysis Group, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hans Zischler
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution (iomE), Molecular Genetics and Genomic Analysis Group, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Holger Herlyn
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany.
| |
Collapse
|
4
|
Benesh DP, Parker G, Chubb JC. Life-cycle complexity in helminths: What are the benefits? Evolution 2021; 75:1936-1952. [PMID: 34184269 DOI: 10.1111/evo.14299] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/23/2021] [Accepted: 06/06/2021] [Indexed: 12/22/2022]
Abstract
Parasitic worms (i.e., helminths) commonly infect multiple hosts in succession. With every transmission step, they risk not infecting the next host and thus dying before reproducing. Given this risk, what are the benefits of complex life cycles? Using a dataset for 973 species of trophically transmitted acanthocephalans, cestodes, and nematodes, we tested whether hosts at the start of a life cycle increase transmission and whether hosts at the end of a life cycle enable growth to larger, more fecund sizes. Helminths with longer life cycles, that is, more successive hosts, infected conspicuously smaller first hosts, slightly larger final hosts, and exploited trophic links with lower predator-prey mass ratios. Smaller first hosts likely facilitate transmission because of their higher abundance and because parasite propagules were the size of their normal food. Bigger definitive hosts likely increase fecundity because parasites grew larger in big hosts, particularly endotherms. Helminths with long life cycles attained larger adult sizes through later maturation, not faster growth. Our results indicate that complex helminth life cycles are ubiquitous because growth and reproduction are highest in large, endothermic hosts that are typically only accessible via small intermediate hosts, that is, the best hosts for growth and transmission are not the same.
Collapse
Affiliation(s)
- Daniel P Benesh
- Molecular Parasitology, Humboldt University, Berlin, Germany.,Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Geoff Parker
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool, UK
| | - James C Chubb
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool, UK
| |
Collapse
|
5
|
Bininda-Emonds ORP. 18S rRNA variability maps reveal three highly divergent, conserved motifs within Rotifera. BMC Ecol Evol 2021; 21:118. [PMID: 34112085 PMCID: PMC8194223 DOI: 10.1186/s12862-021-01845-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 06/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 18S rRNA is a major component of the small subunit of the eukaryotic ribosome and an important phylogenetic marker for many groups, often to the point of being the only marker available for some. A core structure across eukaryotes exists for this molecule that can help to inform about its evolution in different groups. Using an alignment of 18S rDNA for Rotifera as traditionally recognized (=Bdelloidea, Monogononta, and Seisonacea, but not Acanthocephala), I fitted sequences for three exemplar species (Adineta vaga, Brachionus plicatilis, and Seison nebaliae, respectively) to the core structure and used these maps to reveal patterns of evolution for the remainder of this diverse group of microscopic animals. RESULTS The obtained variability maps of the 18S rRNA molecule revealed a pattern of high diversity among the three major rotifer clades coupled with strong conservation within each of bdelloids and monogononts. A majority of individual sites (ca. 60%) were constant even across rotifers as a whole with variable sites showing only intermediate rates of evolution. Although the three structural maps each showed good agreement with the inferred core structure for eukaryotic 18S rRNA and so were highly similar to one another at the secondary and tertiary levels, the overall pattern is of three highly distinct, but conserved motifs within the group at the primary sequence level. A novel finding was that of a variably expressed deletion at the 3' end of the V3 hypervariable region among some bdelloid species that occasionally extended into and included the pseudoknot structure following this region as well as the central "square" of the 18S rRNA molecule. Compared to other groups, levels of variation and rates of evolution for 18S rRNA in Rotifera roughly matched those for Gastropoda and Acanthocephala, despite increasing evidence for the latter being a clade within Rotifera. CONCLUSIONS The lack of comparative data for comparable groups makes interpretation of the results (i.e., very low variation within each of the three major rotifer clades, but high variation between them) and their potential novelty difficult. However, these findings in combination with the high morphological diversity within rotifers potentially help to explain why no clear consensus has been reached to date with regard to the phylogenetic relationships among the major groups.
Collapse
Affiliation(s)
- Olaf R P Bininda-Emonds
- AG Systematics and Evolutionary Biology, IBU-Faculty V, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Strasse 9-11, 26111, Oldenburg, Germany.
| |
Collapse
|
6
|
Nowell RW, Wilson CG, Almeida P, Schiffer PH, Fontaneto D, Becks L, Rodriguez F, Arkhipova IR, Barraclough TG. Evolutionary dynamics of transposable elements in bdelloid rotifers. eLife 2021; 10:e63194. [PMID: 33543711 PMCID: PMC7943196 DOI: 10.7554/elife.63194] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/04/2021] [Indexed: 12/17/2022] Open
Abstract
Transposable elements (TEs) are selfish genomic parasites whose ability to spread autonomously is facilitated by sexual reproduction in their hosts. If hosts become obligately asexual, TE frequencies and dynamics are predicted to change dramatically, but the long-term outcome is unclear. Here, we test current theory using whole-genome sequence data from eight species of bdelloid rotifers, a class of invertebrates in which males are thus far unknown. Contrary to expectations, we find a variety of active TEs in bdelloid genomes, at an overall frequency within the range seen in sexual species. We find no evidence that TEs are spread by cryptic recombination or restrained by unusual DNA repair mechanisms. Instead, we find that that TE content evolves relatively slowly in bdelloids and that gene families involved in RNAi-mediated TE suppression have undergone significant expansion, which might mitigate the deleterious effects of active TEs and compensate for the consequences of long-term asexuality.
Collapse
Affiliation(s)
- Reuben W Nowell
- Department of Zoology, University of OxfordOxfordUnited Kingdom
- Department of Life Sciences, Imperial College London, Silwood Park CampusAscot, BerkshireUnited Kingdom
| | - Christopher G Wilson
- Department of Zoology, University of OxfordOxfordUnited Kingdom
- Department of Life Sciences, Imperial College London, Silwood Park CampusAscot, BerkshireUnited Kingdom
| | - Pedro Almeida
- Department of Life Sciences, Imperial College London, Silwood Park CampusAscot, BerkshireUnited Kingdom
- Division of Biosciences, University College LondonLondonUnited Kingdom
| | - Philipp H Schiffer
- Institute of Zoology, Section Developmental Biology, University of Cologne, KölnWormlabGermany
| | - Diego Fontaneto
- National Research Council of Italy, Water Research InstituteVerbania PallanzaItaly
| | - Lutz Becks
- Community Dynamics Group, Department of Evolutionary Ecology, Max Planck Institute for Evolutionary BiologyPlönGermany
- Aquatic Ecology and Evolution, University of KonstanzKonstanzGermany
| | - Fernando Rodriguez
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MAUnited States
| | - Irina R Arkhipova
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MAUnited States
| | - Timothy G Barraclough
- Department of Zoology, University of OxfordOxfordUnited Kingdom
- Department of Life Sciences, Imperial College London, Silwood Park CampusAscot, BerkshireUnited Kingdom
| |
Collapse
|
7
|
Mauer K, Hellmann SL, Groth M, Fröbius AC, Zischler H, Hankeln T, Herlyn H. The genome, transcriptome, and proteome of the fish parasite Pomphorhynchus laevis (Acanthocephala). PLoS One 2020; 15:e0232973. [PMID: 32574180 PMCID: PMC7310846 DOI: 10.1371/journal.pone.0232973] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/24/2020] [Indexed: 01/05/2023] Open
Abstract
Thorny-headed worms (Acanthocephala) are endoparasites exploiting Mandibulata (Arthropoda) and Gnathostomata (Vertebrata). Despite their world-wide occurrence and economic relevance as a pest, genome and transcriptome assemblies have not been published before. However, such data might hold clues for a sustainable control of acanthocephalans in animal production. For this reason, we present the first draft of an acanthocephalan nuclear genome, besides the mitochondrial one, using the fish parasite Pomphorhynchus laevis (Palaeacanthocephala) as a model. Additionally, we have assembled and annotated the transcriptome of this species and the proteins encoded. A hybrid assembly of long and short reads resulted in a near-complete P. laevis draft genome of ca. 260 Mb, comprising a large repetitive portion of ca. 63%. Numbers of transcripts and translated proteins (35,683) were within the range of other members of the Rotifera-Acanthocephala clade. Our data additionally demonstrate a significant reorganization of the acanthocephalan gene repertoire. Thus, more than 20% of the usually conserved metazoan genes were lacking in P. laevis. Ontology analysis of the retained genes revealed many connections to the incorporation of carotinoids. These are probably taken up via the surface together with lipids, thus accounting for the orange coloration of P. laevis. Furthermore, we found transcripts and protein sequences to be more derived in P. laevis than in rotifers from Monogononta and Bdelloidea. This was especially the case in genes involved in energy metabolism, which might reflect the acanthocephalan ability to use the scarce oxygen in the host intestine for respiration and simultaneously carry out fermentation. Increased plasticity of the gene repertoire through the integration of foreign DNA into the nuclear genome seems to be another underpinning factor of the evolutionary success of acanthocephalans. In any case, energy-related genes and their proteins may be considered as candidate targets for the acanthocephalan control.
Collapse
Affiliation(s)
- Katharina Mauer
- Anthropology, Institute of Organismic and Molecular Evolution (iomE), Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sören Lukas Hellmann
- Molecular Genetics and Genomic Analysis Group, Institute of Organismic and Molecular Evolution (iomE), Johannes Gutenberg University Mainz, Mainz, Germany
| | - Marco Groth
- CF DNA sequencing, Leibniz Institute on Aging–Fritz Lipmann Institute, Jena, Germany
| | - Andreas C. Fröbius
- Molecular Andrology, Biomedical Research Center Seltersberg (BFS), Justus Liebig University Gießen, Gießen, Germany
| | - Hans Zischler
- Anthropology, Institute of Organismic and Molecular Evolution (iomE), Johannes Gutenberg University Mainz, Mainz, Germany
| | - Thomas Hankeln
- Molecular Genetics and Genomic Analysis Group, Institute of Organismic and Molecular Evolution (iomE), Johannes Gutenberg University Mainz, Mainz, Germany
| | - Holger Herlyn
- Anthropology, Institute of Organismic and Molecular Evolution (iomE), Johannes Gutenberg University Mainz, Mainz, Germany
| |
Collapse
|
8
|
|
9
|
Evolution of the bilaterian mouth and anus. Nat Ecol Evol 2018; 2:1358-1376. [PMID: 30135501 DOI: 10.1038/s41559-018-0641-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 06/26/2018] [Accepted: 07/11/2018] [Indexed: 12/17/2022]
Abstract
It is widely held that the bilaterian tubular gut with mouth and anus evolved from a simple gut with one major gastric opening. However, there is no consensus on how this happened. Did the single gastric opening evolve into a mouth, with the anus forming elsewhere in the body (protostomy), or did it evolve into an anus, with the mouth forming elsewhere (deuterostomy), or did it evolve into both mouth and anus (amphistomy)? These questions are addressed by the comparison of developmental fates of the blastopore, the opening of the embryonic gut, in diverse animals that live today. Here we review comparative data on the identity and fate of blastoporal tissue, investigate how the formation of the through-gut relates to the major body axes, and discuss to what extent evolutionary scenarios are consistent with these data. Available evidence indicates that stem bilaterians had a slit-like gastric opening that was partially closed in subsequent evolution, leaving open the anus and most likely also the mouth, which would favour amphistomy. We discuss remaining difficulties, and outline directions for future research.
Collapse
|
10
|
Probing recalcitrant problems in polyclad evolution and systematics with novel mitochondrial genome resources. Genomics 2018; 111:343-355. [PMID: 29486209 DOI: 10.1016/j.ygeno.2018.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/13/2018] [Accepted: 02/16/2018] [Indexed: 11/23/2022]
Abstract
For their apparent morphological simplicity, the Platyhelminthes or "flatworms" are a diverse clade found in a broad range of habitats. Their body plans have however made them difficult to robustly classify. Molecular evidence is only beginning to uncover the true evolutionary history of this clade. Here we present nine novel mitochondrial genomes from the still undersampled orders Polycladida and Rhabdocoela, assembled from short Illumina reads. In particular we present for the first time in the literature the mitochondrial sequence of a Rhabdocoel, Bothromesostoma personatum (Typhloplanidae, Mesostominae). The novel mitochondrial genomes examined generally contained the 36 genes expected in the Platyhelminthes, with all possessing 12 of the 13 protein-coding genes normally found in metazoan mitochondrial genomes (ATP8 being absent from all Platyhelminth mtDNA sequenced to date), along with two ribosomal RNA genes. The majority presented possess 22 transfer RNA genes, and a single tRNA gene was absent from two of the nine assembled genomes. By comparison of mitochondrial gene order and phylogenetic analysis of the protein coding and ribosomal RNA genes contained within these sequences with those of previously sequenced species we are able to gain a firm molecular phylogeny for the inter-relationships within this clade. Our phylogenetic reconstructions, using both nucleotide and amino acid sequences under several models and both Bayesian and Maximum Likelihood methods, strongly support the monophyly of Polycladida, and the monophyly of Acotylea and Cotylea within that clade. They also allow us to speculate on the early emergence of Macrostomida, the monophyly of a "Turbellarian-like" clade, the placement of Rhabditophora, and that of Platyhelminthes relative to the Lophotrochozoa (=Spiralia). The data presented here therefore represent a significant advance in our understanding of platyhelminth phylogeny, and will form the basis of a range of future research in the still-disputed classifications within this taxon.
Collapse
|
11
|
Enigmatic Gnathostomulida (Gnathifera, Spiralia): about monociliated pharyngeal receptors and the pharyngeal nervous system. ZOOMORPHOLOGY 2017. [DOI: 10.1007/s00435-017-0369-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
12
|
Herlyn H. Organization and evolution of the proboscis musculature in avian parasites of the genus Apororhynchus (Acanthocephala: Apororhynchida). Parasitol Res 2017; 116:1801-1810. [DOI: 10.1007/s00436-017-5440-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/06/2017] [Indexed: 10/19/2022]
|
13
|
Gribble KE, Mark Welch DB. Genome-wide transcriptomics of aging in the rotifer Brachionus manjavacas, an emerging model system. BMC Genomics 2017; 18:217. [PMID: 28249563 PMCID: PMC5333405 DOI: 10.1186/s12864-017-3540-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/02/2017] [Indexed: 12/22/2022] Open
Abstract
Background Understanding gene expression changes over lifespan in diverse animal species will lead to insights to conserved processes in the biology of aging and allow development of interventions to improve health. Rotifers are small aquatic invertebrates that have been used in aging studies for nearly 100 years and are now re-emerging as a modern model system. To provide a baseline to evaluate genetic responses to interventions that change health throughout lifespan and a framework for new hypotheses about the molecular genetic mechanisms of aging, we examined the transcriptome of an asexual female lineage of the rotifer Brachionus manjavacas at five life stages: eggs, neonates, and early-, late-, and post-reproductive adults. Results There are widespread shifts in gene expression over the lifespan of B. manjavacas; the largest change occurs between neonates and early reproductive adults and is characterized by down-regulation of developmental genes and up-regulation of genes involved in reproduction. The expression profile of post-reproductive adults was distinct from that of other life stages. While few genes were significantly differentially expressed in the late- to post-reproductive transition, gene set enrichment analysis revealed multiple down-regulated pathways in metabolism, maintenance and repair, and proteostasis, united by genes involved in mitochondrial function and oxidative phosphorylation. Conclusions This study provides the first examination of changes in gene expression over lifespan in rotifers. We detected differential expression of many genes with human orthologs that are absent in Drosophila and C. elegans, highlighting the potential of the rotifer model in aging studies. Our findings suggest that small but coordinated changes in expression of many genes in pathways that integrate diverse functions drive the aging process. The observation of simultaneous declines in expression of genes in multiple pathways may have consequences for health and longevity not detected by single- or multi-gene knockdown in otherwise healthy animals. Investigation of subtle but genome-wide change in these pathways during aging is an important area for future study. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3540-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kristin E Gribble
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, 02543, USA
| | - David B Mark Welch
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, 02543, USA.
| |
Collapse
|
14
|
Evolutionary anatomy of the muscular apparatus involved in the anchoring of Acanthocephala to the intestinal wall of their vertebrate hosts. Parasitol Res 2017; 116:1207-1225. [PMID: 28233104 DOI: 10.1007/s00436-017-5398-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/27/2017] [Indexed: 10/20/2022]
Abstract
Different conceptions exist regarding structure, function, and evolution of the muscles that move the acanthocephalan presoma, including the proboscis, i.e., the usually hooked hold-fast anchoring these endoparasites to the intestinal wall of their vertebrate definitive hosts. In order to clarify the unresolved issues, we carried out a light microscopic analysis of series of semi-thin sections and whole mounts representing the three traditional acanthocephalan classes: Archiacanthocephala (Macracanthorhynchus hirudinaceus), Eoacanthocephala (Paratenuisentis ambiguus, Tenuisentis niloticus), and Palaeacanthocephala (Acanthocephalus anguillae, Echinorhynchus truttae, Pomphorhynchus laevis, Corynosoma sp.). Combining our data with published light, transmission electron, and scanning electron microscopic data, we demonstrate that receptacle protrusor and proboscis receptacle in Archi- and Eoacanthocephala are homologous to the outer and inner wall of the proboscis receptacle in Palaeacanthocephala. Besides the proboscis receptacle and a "surrounding muscle," the last common ancestor of Acanthocephala presumably possessed a proboscis retractor, receptacle retractor, neck retractor (continuous with lemnisci compressors), and retinacula. These muscles most probably evolved in the acanthocephalan stem line. Moreover, the last common ancestor of Acanthocephala presumably possessed only a single layer of muscular cords under the presomal tegument while the metasomal body wall had circular and longitudinal strands. Two lateral receptacle flexors (also lateral receptacle protrusors), an apical muscle plate (surrounding one or two apical sensory organs), a midventral longitudinal muscle, and the differentiation of longitudinal body wall musculature at the base of the proboscis probably emerged within Archiacanthocephala. All muscles have a common organization principle: a peripheral layer of contractile filaments encloses the cytoplasm.
Collapse
|
15
|
|
16
|
Gazi M, Kim J, García-Varela M, Park C, Littlewood DTJ, Park JK. Mitogenomic phylogeny of Acanthocephala reveals novel Class relationships. ZOOL SCR 2016. [DOI: 10.1111/zsc.12160] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohiuddin Gazi
- Program in Cell Biology and Genetics; College of Medicine; Chungbuk National University; Cheongju 28644 Korea
| | - Jiyeon Kim
- Division of EcoScience; Ewha Womans University; 52 Ewhayeodae-gil Seodaemun-gu Seoul 03760 Korea
| | - Martín García-Varela
- Departamento de Zoología; Instituto de Biología; Universidad Nacional Autónoma de México; Avenida Universidad 3000 Ciudad Universitaria C.P. 04510 Distrito Federal Mexico
| | - Chungoo Park
- School of Biological Sciences and Technology; Chonnam National University; Gwangju 61186 Korea
| | - D. Tim J. Littlewood
- Department of Life Sciences; Natural History Museum; Cromwell Road London SW7 5BD UK
| | - Joong-Ki Park
- Division of EcoScience; Ewha Womans University; 52 Ewhayeodae-gil Seodaemun-gu Seoul 03760 Korea
| |
Collapse
|
17
|
Hejnol A, Lowe CJ. Embracing the comparative approach: how robust phylogenies and broader developmental sampling impacts the understanding of nervous system evolution. Philos Trans R Soc Lond B Biol Sci 2015; 370:20150045. [PMID: 26554039 PMCID: PMC4650123 DOI: 10.1098/rstb.2015.0045] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2015] [Indexed: 12/14/2022] Open
Abstract
Molecular biology has provided a rich dataset to develop hypotheses of nervous system evolution. The startling patterning similarities between distantly related animals during the development of their central nervous system (CNS) have resulted in the hypothesis that a CNS with a single centralized medullary cord and a partitioned brain is homologous across bilaterians. However, the ability to precisely reconstruct ancestral neural architectures from molecular genetic information requires that these gene networks specifically map with particular neural anatomies. A growing body of literature representing the development of a wider range of metazoan neural architectures demonstrates that patterning gene network complexity is maintained in animals with more modest levels of neural complexity. Furthermore, a robust phylogenetic framework that provides the basis for testing the congruence of these homology hypotheses has been lacking since the advent of the field of 'evo-devo'. Recent progress in molecular phylogenetics is refining the necessary framework to test previous homology statements that span large evolutionary distances. In this review, we describe recent advances in animal phylogeny and exemplify for two neural characters-the partitioned brain of arthropods and the ventral centralized nerve cords of annelids-a test for congruence using this framework. The sequential sister taxa at the base of Ecdysozoa and Spiralia comprise small, interstitial groups. This topology is not consistent with the hypothesis of homology of tripartitioned brain of arthropods and vertebrates as well as the ventral arthropod and rope-like ladder nervous system of annelids. There can be exquisite conservation of gene regulatory networks between distantly related groups with contrasting levels of nervous system centralization and complexity. Consequently, the utility of molecular characters to reconstruct ancestral neural organization in deep time is limited.
Collapse
Affiliation(s)
- Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, Bergen 5008, Norway
| | - Christopher J Lowe
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Oceanview Blvd., Pacific Grove, CA 93950, USA
| |
Collapse
|
18
|
Sielaff M, Schmidt H, Struck TH, Rosenkranz D, Mark Welch DB, Hankeln T, Herlyn H. Phylogeny of Syndermata (syn. Rotifera): Mitochondrial gene order verifies epizoic Seisonidea as sister to endoparasitic Acanthocephala within monophyletic Hemirotifera. Mol Phylogenet Evol 2015; 96:79-92. [PMID: 26702959 DOI: 10.1016/j.ympev.2015.11.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/19/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
Abstract
A monophyletic origin of endoparasitic thorny-headed worms (Acanthocephala) and wheel-animals (Rotifera) is widely accepted. However, the phylogeny inside the clade, be it called Syndermata or Rotifera, has lacked validation by mitochondrial (mt) data. Herein, we present the first mt genome of the key taxon Seison and report conflicting results of phylogenetic analyses: while mt sequence-based topologies showed monophyletic Lemniscea (Bdelloidea+Acanthocephala), gene order analyses supported monophyly of Pararotatoria (Seisonidea+Acanthocephala) and Hemirotifera (Bdelloidea+Pararotatoria). Sequence-based analyses obviously suffered from substitution saturation, compositional bias, and branch length heterogeneity; however, we observed no compromising effects in gene order analyses. Moreover, gene order-based topologies were robust to changes in coding (genes vs. gene pairs, two-state vs. multistate, aligned vs. non-aligned), tree reconstruction methods, and the treatment of the two monogonont mt genomes. Thus, mt gene order verifies seisonids as sister to acanthocephalans within monophyletic Hemirotifera, while deviating results of sequence-based analyses reflect artificial signal. This conclusion implies that the complex life cycle of extant acanthocephalans evolved from a free-living state, as retained by most monogononts and bdelloids, via an epizoic state with a simple life cycle, as shown by seisonids. Hence, Acanthocephala represent a rare example where ancestral transitional stages have counterparts amongst the closest relatives.
Collapse
Affiliation(s)
- Malte Sielaff
- Institute of Molecular Genetics, Johannes Gutenberg-University Mainz, J.J. Becher-Weg 30a, D-55099 Mainz, Germany
| | - Hanno Schmidt
- Institute of Molecular Genetics, Johannes Gutenberg-University Mainz, J.J. Becher-Weg 30a, D-55099 Mainz, Germany
| | - Torsten H Struck
- National Centre for Biosystematics, Natural History Museum, University of Oslo, P.O. Box 1172, Blindern, NO-0318 Oslo, Norway
| | - David Rosenkranz
- Institute of Anthropology, Johannes Gutenberg-University Mainz, Anselm-Franz-von-Bentzel-Weg 7, D-55099 Mainz, Germany
| | - David B Mark Welch
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Thomas Hankeln
- Institute of Molecular Genetics, Johannes Gutenberg-University Mainz, J.J. Becher-Weg 30a, D-55099 Mainz, Germany
| | - Holger Herlyn
- Institute of Anthropology, Johannes Gutenberg-University Mainz, Anselm-Franz-von-Bentzel-Weg 7, D-55099 Mainz, Germany.
| |
Collapse
|
19
|
Gazi M, Kim J, Park JK. The complete mitochondrial genome sequence of Southwellina hispida supports monophyly of Palaeacanthocephala (Acanthocephala: Polymorphida). Parasitol Int 2015; 64:64-8. [DOI: 10.1016/j.parint.2015.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 01/17/2015] [Accepted: 01/26/2015] [Indexed: 10/24/2022]
|
20
|
Hochberg R, Wallace RL, Walsh EJ. Soft Bodies, Hard Jaws: An Introduction to the Symposium, with Rotifers as Models of Jaw Diversity. Integr Comp Biol 2015; 55:179-92. [PMID: 25796591 PMCID: PMC6296403 DOI: 10.1093/icb/icv002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Jaws have evolved numerous times in the animal kingdom and they display a wide variety of structural, compositional, and functional characteristics that reflect their polyphyletic origins. Among soft-bodied invertebrates, jaws are known from annelids, chaetognaths, flatworms, gnathostomulids, micrognathozoans, mollusks, rotifers, and several ecdysozoans. Depending on the taxon, jaws may function in the capture of prey (e.g., chaetognaths and flatworms), processing of prey (e.g., gnathostomulids and onychophorans), or both (e.g., rotifers). Although structural diversity among invertebrates’ jaws is becoming better characterized with the use of electron microscopy, many details remain poorly described, including neuromuscular control, elemental composition, and physical characteristics, such as hardness and resistance to wear. Unfortunately, absence of relevant data has impeded understanding of their functional diversity and evolutionary origins. With this symposium, we bring together researchers of disparately jawed taxa to draw structural and mechanistic comparisons among species to determine their commonalities. Additionally, we show that rotifers’ jaws, which are perhaps the best-characterized jaws among invertebrates, are still enigmatic with regard to their origins and mechanics. Nevertheless, technologies such as energy dispersive X-ray spectroscopy (EDX) and 3D modeling are being used to characterize their chemical composition and to develop physical models that allow exploration of their mechanical properties, respectively. We predict that these methods can also be used to develop biomimetic and bioinspired constructs based on the full range of the complexity of jaws, and that such constructs also can be developed from other invertebrate taxa. These approaches may also shed light on common developmental and physiological processes that facilitate the evolution of invertebrates’ jaws.
Collapse
Affiliation(s)
- Rick Hochberg
- *Department of Biology, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA
| | - Robert L. Wallace
- Biology Department, Ripon College, 300 Seward Street, Ripon, WI 54971, USA
| | - Elizabeth J. Walsh
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| |
Collapse
|
21
|
Gu S, Li L, Liang L, Liu X, Ouyang K, Li J, Yang J. Spermatozoon of the freshwater rotifer Brachionus calyciflorus (Rotifera, Monogononta): Advances in morphological and ultrastructural studies. Micron 2015; 76:6-13. [PMID: 26021257 DOI: 10.1016/j.micron.2015.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/04/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
Abstract
The morphological and ultrastructural features of the spermatozoon in Brachionus calyciflorus are described using light, fluorescence and transmission electron microscopy (TEM). The mature spermatozoon, which appears to be thread-like, is composed of a slightly expanded anterior of cell body region and a flagellum region without acrosome. The cell body region and flagellum region are respectively 16-27μm and 20-33μm in length (n=60). The spermatozoon is characterized by a mass of dense tubular materials, which occupy most of the cell. Some mitochondria are distributed around the nuclear region in the anterior of the cell body region, while in the posterior portion of cell body, the chromatin often contains a single lobated nucleus arranged at the center of cell. The flagellum contains the classic axoneme (9×2+2) and possesses lateral undulating membrane. Mature B. calyciflorus males have no germ cell stages earlier than the spermatids in the testis. TEM examination reveals rigid rods as well as predominant typical spermatozoon in the testis. Observations, based on successive photographs and videos, enabled a first-time recording of the unique inverted movement of the spermatozoon, which indicated that the movement of the spermatozoon is driven by the flagellum. Our study also provides further supplementary insights into the phylogenetic systematics of the Rotifera.
Collapse
Affiliation(s)
- Shuyu Gu
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China.
| | - Lian Li
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Luxiaoxue Liang
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Xuezhou Liu
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Kai Ouyang
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Jing Li
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Jiaxin Yang
- Jiangsu Province Key Laboratory for Aquatic Live Food, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China.
| |
Collapse
|
22
|
|
23
|
Giribet G. Morphology should not be forgotten in the era of genomics–a phylogenetic perspective. ZOOL ANZ 2015. [DOI: 10.1016/j.jcz.2015.01.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Golombek A, Tobergte S, Struck TH. Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes). Mol Phylogenet Evol 2015; 86:49-63. [DOI: 10.1016/j.ympev.2015.02.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/18/2015] [Accepted: 02/17/2015] [Indexed: 01/06/2023]
|
25
|
Egger B, Lapraz F, Tomiczek B, Müller S, Dessimoz C, Girstmair J, Škunca N, Rawlinson KA, Cameron CB, Beli E, Todaro MA, Gammoudi M, Noreña C, Telford MJ. A transcriptomic-phylogenomic analysis of the evolutionary relationships of flatworms. Curr Biol 2015; 25:1347-53. [PMID: 25866392 PMCID: PMC4446793 DOI: 10.1016/j.cub.2015.03.034] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/27/2015] [Accepted: 03/19/2015] [Indexed: 02/05/2023]
Abstract
The interrelationships of the flatworms (phylum Platyhelminthes) are poorly resolved despite decades of morphological and molecular phylogenetic studies [1, 2]. The earliest-branching clades (Catenulida, Macrostomorpha, and Polycladida) share spiral cleavage and entolecithal eggs with other lophotrochozoans. Lecithoepitheliata have primitive spiral cleavage but derived ectolecithal eggs. Other orders (Rhabdocoela, Proseriata, Tricladida and relatives, and Bothrioplanida) all have derived ectolecithal eggs but have uncertain affinities to one another. The orders of parasitic Neodermata emerge from an uncertain position from within these ectolecithal classes. To tackle these problems, we have sequenced transcriptomes from 18 flatworms and 5 other metazoan groups. The addition of published data produces an alignment of >107,000 amino acids with less than 28% missing data from 27 flatworm taxa in 11 orders covering all major clades. Our phylogenetic analyses show that Platyhelminthes consist of the two clades Catenulida and Rhabditophora. Within Rhabditophora, we show the earliest-emerging branch is Macrostomorpha, not Polycladida. We show Lecithoepitheliata are not members of Neoophora but are sister group of Polycladida, implying independent origins of the ectolecithal eggs found in Lecithoepitheliata and Neoophora. We resolve Rhabdocoela as the most basally branching euneoophoran taxon. Tricladida, Bothrioplanida, and Neodermata constitute a group that appears to have lost both spiral cleavage and centrosomes. We identify Bothrioplanida as the long-sought closest free-living sister group of the parasitic Neodermata. Among parasitic orders, we show that Cestoda are closer to Trematoda than to Monogenea, rejecting the concept of the Cercomeromorpha. Our results have important implications for understanding the evolution of this major phylum. Phylogenomics provide insights into the interrelationships of Platyhelminthes Macrostomorpha are the basalmost rhabditophorans Polycladida are sister group of Lecithoepitheliata/Prorhynchida Bothrioplanida are the free-living sister group of Neodermata
Collapse
Affiliation(s)
- Bernhard Egger
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK; Institute of Zoology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - François Lapraz
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Bartłomiej Tomiczek
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Steven Müller
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Christophe Dessimoz
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK; Department of Computer Science, University College London, Gower Street, London WC1E 6BT, UK
| | - Johannes Girstmair
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Nives Škunca
- ETH Zurich, Department of Computer Science, Universitätsstrasse 19, 8092 Zurich, Switzerland
| | - Kate A Rawlinson
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Christopher B Cameron
- Université de Montréal, Département de Sciences Biologiques, Pavillon Marie-Victorin, CP 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Elena Beli
- Université de Montréal, Département de Sciences Biologiques, Pavillon Marie-Victorin, CP 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada; Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
| | - M Antonio Todaro
- Università degli Studi di Modena e Reggio Emilia, Via Campi 213/d, 41100 Modena, Italy
| | - Mehrez Gammoudi
- Université Tunis El-Manar Campus Universitaire, 2092 Tunis, Tunisia
| | - Carolina Noreña
- Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Maximilian J Telford
- Department Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
26
|
De Baets K, Littlewood DTJ. The Importance of Fossils in Understanding the Evolution of Parasites and Their Vectors. ADVANCES IN PARASITOLOGY 2015; 90:1-51. [PMID: 26597064 DOI: 10.1016/bs.apar.2015.07.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Knowledge concerning the diversity of parasitism and its reach across our current understanding of the tree of life has benefitted considerably from novel molecular phylogenetic methods. However, the timing of events and the resolution of the nature of the intimate relationships between parasites and their hosts in deep time remain problematic. Despite its vagaries, the fossil record provides the only direct evidence of parasites and parasitism in the fossil record of extant and extinct lineages. Here, we demonstrate the potential of the fossil record and other lines of geological evidence to calibrate the origin and evolution of parasitism by combining different kinds of dating evidence with novel molecular clock methodologies. Other novel methods promise to provide additional evidence for the presence or the life habit of pathogens and their vectors, including the discovery and analysis of ancient DNA and other biomolecules, as well as computed tomographic methods.
Collapse
|
27
|
Dunn CW, Giribet G, Edgecombe GD, Hejnol A. Animal Phylogeny and Its Evolutionary Implications. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2014. [DOI: 10.1146/annurev-ecolsys-120213-091627] [Citation(s) in RCA: 261] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Casey W. Dunn
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912;
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138;
| | - Gregory D. Edgecombe
- Department of Earth Sciences, The Natural History Museum, London SW7 5BD, United Kingdom;
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5008 Bergen, Norway;
| |
Collapse
|
28
|
Struck TH, Wey-Fabrizius AR, Golombek A, Hering L, Weigert A, Bleidorn C, Klebow S, Iakovenko N, Hausdorf B, Petersen M, Kück P, Herlyn H, Hankeln T. Platyzoan paraphyly based on phylogenomic data supports a noncoelomate ancestry of spiralia. Mol Biol Evol 2014; 31:1833-49. [PMID: 24748651 DOI: 10.1093/molbev/msu143] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Based on molecular data three major clades have been recognized within Bilateria: Deuterostomia, Ecdysozoa, and Spiralia. Within Spiralia, small-sized and simply organized animals such as flatworms, gastrotrichs, and gnathostomulids have recently been grouped together as Platyzoa. However, the representation of putative platyzoans was low in the respective molecular phylogenetic studies, in terms of both, taxon number and sequence data. Furthermore, increased substitution rates in platyzoan taxa raised the possibility that monophyletic Platyzoa represents an artifact due to long-branch attraction. In order to overcome such problems, we employed a phylogenomic approach, thereby substantially increasing 1) the number of sampled species within Platyzoa and 2) species-specific sequence coverage in data sets of up to 82,162 amino acid positions. Using established and new measures (long-branch score), we disentangled phylogenetic signal from misleading effects such as long-branch attraction. In doing so, our phylogenomic analyses did not recover a monophyletic origin of platyzoan taxa that, instead, appeared paraphyletic with respect to the other spiralians. Platyhelminthes and Gastrotricha formed a monophylum, which we name Rouphozoa. To the exclusion of Gnathifera, Rouphozoa and all other spiralians represent a monophyletic group, which we name Platytrochozoa. Platyzoan paraphyly suggests that the last common ancestor of Spiralia was a simple-bodied organism lacking coelomic cavities, segmentation, and complex brain structures, and that more complex animals such as annelids evolved from such a simply organized ancestor. This conclusion contradicts alternative evolutionary scenarios proposing an annelid-like ancestor of Bilateria and Spiralia and several independent events of secondary reduction.
Collapse
Affiliation(s)
- Torsten H Struck
- Zoological Research Museum Alexander Koenig, Bonn, GermanyUniversity of Osnabrück, FB05 Biology/Chemistry, AG Zoology, Osnabrück, Germany
| | - Alexandra R Wey-Fabrizius
- Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg University, Mainz, Germany
| | - Anja Golombek
- Zoological Research Museum Alexander Koenig, Bonn, Germany
| | - Lars Hering
- Animal Evolution and Development, Institute of Biology II, University of Leipzig, Leipzig, Germany
| | - Anne Weigert
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Leipzig, Germany
| | - Christoph Bleidorn
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Leipzig, Germany
| | - Sabrina Klebow
- Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg University, Mainz, Germany
| | - Nataliia Iakovenko
- Department of Biology and Ecology, Ostravian University in Ostrava, Ostrava, Czech RepublicDepartment of Invertebrate Fauna and Systematics, Schmalhausen Institute of Zoology NAS of Ukraine, Kyiv, Ukraine
| | | | - Malte Petersen
- Zoological Research Museum Alexander Koenig, Bonn, Germany
| | - Patrick Kück
- Zoological Research Museum Alexander Koenig, Bonn, Germany
| | - Holger Herlyn
- Institute of Anthropology, Johannes Gutenberg University, Mainz, Germany
| | - Thomas Hankeln
- Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg University, Mainz, Germany
| |
Collapse
|