DOCSLIB.ORG

Are Viroids Negative-Strand Viruses?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Are Viroids Negative-Strand Viruses? 850 Nature Vol. 276 21/28 December 1978 Myriapoda-Hexapoda assemblage' and to the Uniramia or against a polyphyletic Second, an increase in amount (and in 7 give a name, the Uniramia, to this group • concept of arthropodan evolution. radioactive labelling) of two polypeptide The component taxa are united on their S. M. MANTON bands in polyacrylamide gels was found in 4 basic arthropodan features; their parti­ Zoology Department, CEV-infected plants • MWs assigned to cular type of jaws, and their limbs lacking British Museum (Natural History), the two polypeptides were 18,000 and any trace of true outer ramus. The jointed London SW7, UK 15,000. I have recalculated these MWs as limbs of myriapods and hexapods could, 13,200 and 10,400, using as internal arguably, have been derived from lobo­ I. Locke, M. & Huie. P. Narure 270,341- 343 (1977). markers the large and small subunits podia! limbs essentially resembling those 2. Manton. S.M. J. Linn. Soc .• Zoo/. 56,58-72 (1958). of ribulose-1 ',5' -diphosphatecarboxylase 3. Manton, S.M. 1. nat. Hisr. 1, 1-22 (1967). of the extant Onychophora, and these 4. Manton. S.M. J. Linn. Soc .• Zoo/. 53,257- 375 (1973). (MWs 54,000 and 12,000). The larger of limbs could have been derived from limbs 5. Manton, S.M. J. zoot. R-..171, 111-130 (1974). the CEV -induced polypeptides was of metamerically segmented worms with a 6. Manton , S. M. The Arthropoda : Habits, Functional located preferentially in the histone frac­ Morphology und Evolurion 1- 527 (Odord University haemocoel which, along with the muscles, Press 1977). tion, the smaller was in the non-histone 4 worked the uniramous limbs. As long ago 7. Manton. S.M. J. Linn. Soc .. Zoot. 51,203-400 (1972). fraction . This partitioning fits with the 8 9 8. Ticg>. 0 . W. Q. 11. microsc. Sci. 82, 1-225 (1940); 85, as 1940, Tiegs · emphasised the unity of 191-328 (1945). amino acid composition of the two poly­ these three taxa and Anderson 10 has 9. Tiegs. 0. W. 0. 11. Microsc. Sci. 88, 165-336 (1947). peptide components that could be derived 10. Anderson. D. T. The Embryology und Phylogeny of from the negative strand. shown in detail the common ontogenetic Annelids and ArthFopods 1-495 (Pergamon, Oxford, theme which exists throughout the Uni­ 1973) ramia and contrasts absolutely with that II. Robson. E. A. Q. 11. microsc. Sci. 105,281-299 (1964). 120-127 12. Hackman. R. H. & Goldberg, M. Science 190, 582-583 /AAAGGGGG pervading the entire crustacean group. (1975). Further, crustecean ontogeny could not 13. Manton. S.M. Phil. Trans. R. Soc. B. 2Z7, 411-464. have been derived from that of any known annelidan group. In contrast, the uni­ Are viroids ramian ontogeny might have been derived negative-strand viruses? from that of some yolky-egged annelid or annelid-like worm which possessed a IN their paper detailing the complete haemocoel and lobopodia, but not sequence of 359 bases in potato spindle coelomate parapodia. tuber viroid (PSTV) RNA, Gross et a/. 1 2 There is no justification on the basis of considered, as have other workers , that Golgi phenomena for the restriction of the the circular single-stranded molecule is term Uniramia to the Myriapoda and unlikely to function as a messenger RNA. Hexapoda alone, nor for the exclusion The possibility that PSTV RNA might be from the arthropods of any animal on one a non-coding strand rather than a positive character alone. That the Onychophora (coding) strand may have been over­ are thoroughly arthropodan is shown by looked. Fig. 1 Model of a PSTV RNA strand 11 12 their cuticle · , which contains protein I have examined the base sequence complementary to the viroid strand 1 and chitin, but not collagen, in contrast to complementary to that established by sequenced by Gross el a/. • The heavy line 1 represents the circular RNA. The annelids; by the presence of an ecdysial Grosset al. • Four possible initiation trip­ 1 numbers 1 and 359 indicate the same start cycle as in other arthropods \ the cuticle lets (all GUG) and six possible strong being shed in one piece, as in no other termination triplets could result in four position as that used by Gross eta/., but because the strand represented here is invertebrates on Locke and Huie's list\ polypeptides containing 108, 79, 43 or 28 antiparallel to the viroid strand, the posi­ and by the general anatomy of the Ony­ amino acids, of which the two larger (with tion of base 1 in this diagram is equivalent chophora, which tallies with that of other molecular weights (MWs) 11,300 and to that of base ]59 in the viroid sequence. uniramian taxa. We do not know the 8,500) are the more interesting. The Dashed line, polypeptide of MW 11,300; significance of onychophoran Golgi longest of these sequences begins with a dotted-dashed line, polypeptide of MW phenomena nor of its association with GUG at positions 134-136 and teminates 8,500. unstriated muscle, but this one feature is at a double U AG at positions 99-104 (Fig. no acceptable reason to disrupt the Uni­ 1). The GUG is preceded by a well-placed In the light of the above evidence I ramia or exclude the Onychophora from potential ribosome recognition sequence suggest that viroids may be very small the arthropods. as indicated in Fig. 1. The second potential negative-strand viruses with the following Thus, without further consideration of polypeptide is in a different reading frame properties. (1) They use secondary struc­ the several other arthropodan taxa, it is and begins with a GUG at residues 177- ture rather than a protein coat for protec­ clear that the Uniramia and Crustacea 179. It is preceded by an unbroken tion of the genome; (2) they use a host each represent well defined arthropodan sequence of 14 purines, and teminates in polymerase to make a complementary taxa, which could not have originated an UAG at residues 55-57. The amino RNA strand; and (3) this strand serves as a from common annelidan ancestry, and acid composition of the small polypeptide template for progeny viroid particles and that their cuticles must have evolved in is unremarkable except for a high content as message for one or two viroid proteins. parallel. of phenylalanine (1 0% ), but the larger This hypothesis can be tested by a search The exoskeleton of all arthropods has polypeptide has a content of arginine in PSTV -infected tissues for one or two the same mechanical functions in provi­ (11 %) and lysine (5%) that would give it viroid-induced polypeptides of the pre­ ding unstretchable cuticles, sclerites and histone-like properties. dicted size and composition. arthrodial membranes concerned with Two experimental observations would R. E. F. MATTHEWS trunk movements and muscle insertions. fit with the view that one or both of these Department of Cell Biology, The requirements of other invertebrates polypeptides are produced by viroids. University of Auckland, are different. The cuticles of the various First, there is evidence for an RNA strand Private Bag, Auckland, arthropodan taxa are not identical, complementary to citrus exocortis viroid 3 New Zealand although protein and fine-fibre systems (CEV) RNA in infected tissues ; CEV is 2 form the basis of most sclerites. There is fairly closely related to PSTV . Some of I. Gross. H. J. <tal. Nature Z73, 2113-208 (1978). 2. Diener, T. 0. & Hadidi, A. 01mprehensive Virol. 11, thus no reason that the general manner of the hybridisable RNA was in the nuclear 285-337 (1977). formation of arthropod cuticle may not fraction but more was in the soluble cyto­ 3. Grill, L. K. & S~mancik, .L S. Proc. natn. Acad. Sci. U.S.A. 75, 8%- 900 ( 1978). have evolved more than once; nor is there plasmic fraction, where it might have 4. Conejero, V. & Semancik. J. S. Virology 77, 221-232 any sound evidence against the unity of possessed a messenger function. (1977). 0028-0836/78/02 76--V850$0 1.00 © Macmillan Journals Lid Wl\\ .
Load more

Recommended publications
  • New Zealand's Genetic Diversity
    1.13 NEW ZEALAND’S GENETIC DIVERSITY NEW ZEALAND’S GENETIC DIVERSITY Dennis P. Gordon National Institute of Water and Atmospheric Research, Private Bag 14901, Kilbirnie, Wellington 6022, New Zealand ABSTRACT: The known genetic diversity represented by the New Zealand biota is reviewed and summarised, largely based on a recently published New Zealand inventory of biodiversity. All kingdoms and eukaryote phyla are covered, updated to refl ect the latest phylogenetic view of Eukaryota. The total known biota comprises a nominal 57 406 species (c. 48 640 described). Subtraction of the 4889 naturalised-alien species gives a biota of 52 517 native species. A minimum (the status of a number of the unnamed species is uncertain) of 27 380 (52%) of these species are endemic (cf. 26% for Fungi, 38% for all marine species, 46% for marine Animalia, 68% for all Animalia, 78% for vascular plants and 91% for terrestrial Animalia). In passing, examples are given both of the roles of the major taxa in providing ecosystem services and of the use of genetic resources in the New Zealand economy. Key words: Animalia, Chromista, freshwater, Fungi, genetic diversity, marine, New Zealand, Prokaryota, Protozoa, terrestrial. INTRODUCTION Article 10b of the CBD calls for signatories to ‘Adopt The original brief for this chapter was to review New Zealand’s measures relating to the use of biological resources [i.e. genetic genetic resources. The OECD defi nition of genetic resources resources] to avoid or minimize adverse impacts on biological is ‘genetic material of plants, animals or micro-organisms of diversity [e.g. genetic diversity]’ (my parentheses).
    [Show full text]
  • An Ordovician Lobopodian from the Soom Shale Lagerstätte, South Africa
    [Palaeontology, Vol. 52, Part 3, 2009, pp. 561–567] AN ORDOVICIAN LOBOPODIAN FROM THE SOOM SHALE LAGERSTA¨ TTE, SOUTH AFRICA by ROWAN J. WHITTLE*,à, SARAH E. GABBOTT*, RICHARD J. ALDRIDGE* and JOHANNES THERON *Department of Geology, University of Leicester, Leicester LE1 7RH, UK; e-mails: [email protected]; [email protected] Department of Geology, University of Stellenbosch, Private Bag XI, Stellenbosch 7602, South Africa; e-mail: [email protected] àPresent address: British Antarctic Survey, Madingley Road, Cambridge, CB3 0ET, UK; e-mail: [email protected] Typescript received 18 July 2008; accepted in revised form 27 January 2009 Abstract: The first lobopodian known from the Ordovician and Carboniferous. The new fossil preserves an annulated is described from the Soom Shale Lagersta¨tte, South Africa. trunk, lobopods with clear annulations, and curved claws. It The organism shows features homologous to Palaeozoic mar- represents a rare record of a benthic organism from the ine lobopodians described from the Middle Cambrian Bur- Soom Shale, and demonstrates intermittent water oxygena- gess Shale, the Lower Cambrian Chengjiang biota, the Lower tion during the deposition of the unit. Cambrian Sirius Passet Lagersta¨tte and the Lower Cambrian of the Baltic. The discovery provides a link between marine Key words: Lagersta¨tte, lobopodian, Ordovician, Soom Cambrian lobopodians and younger forms from the Silurian Shale. Cambrian lobopodians are a diverse group showing a in an intracratonic basin with water depths of approxi- great variety of body shape, size and ornamentation. mately 100 m (Gabbott 1999). Dominantly quiet water However, they share a segmented onychophoran-like conditions are indicated by a lack of flow-induced sedi- body, paired soft-skinned annulated lobopods, and in mentary structures and the taphonomy of the fossils.
    [Show full text]
  • The Comparative Embryology of Sponges Alexander V
    The Comparative Embryology of Sponges Alexander V. Ereskovsky The Comparative Embryology of Sponges Alexander V. Ereskovsky Department of Embryology Biological Faculty Saint-Petersburg State University Saint-Petersburg Russia [email protected] Originally published in Russian by Saint-Petersburg University Press ISBN 978-90-481-8574-0 e-ISBN 978-90-481-8575-7 DOI 10.1007/978-90-481-8575-7 Springer Dordrecht Heidelberg London New York Library of Congress Control Number: 2010922450 © Springer Science+Business Media B.V. 2010 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preface It is generally assumed that sponges (phylum Porifera) are the most basal metazoans (Kobayashi et al. 1993; Li et al. 1998; Mehl et al. 1998; Kim et al. 1999; Philippe et al. 2009). In this connection sponges are of a great interest for EvoDevo biolo- gists. None of the problems of early evolution of multicellular animals and recon- struction of a natural system of their main phylogenetic clades can be discussed without considering the sponges. These animals possess the extremely low level of tissues organization, and demonstrate extremely low level of processes of gameto- genesis, embryogenesis, and metamorphosis. They show also various ways of advancement of these basic mechanisms that allow us to understand processes of establishment of the latter in the early Metazoan evolution.
    [Show full text]
  • New Data on Spermatogenic Cyst Formation and Cellular Composition of the Testis in a Marine Gastropod, Littorina Saxatilis
    International Journal of Molecular Sciences Article New Data on Spermatogenic Cyst Formation and Cellular Composition of the Testis in a Marine Gastropod, Littorina saxatilis Sergei Iu. Demin 1,*, Dmitry S. Bogolyubov 1,* , Andrey I. Granovitch 2 and Natalia A. Mikhailova 1,2 1 Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia; [email protected] 2 Department of Invertebrate Zoology, St. Petersburg State University, 7/9 Universitetskaya Emb., 199034 St. Petersburg, Russia; [email protected] * Correspondence: [email protected] (S.I.D.); [email protected] (D.S.B.) Received: 29 April 2020; Accepted: 25 May 2020; Published: 27 May 2020 Abstract: Knowledge of the testis structure is important for gastropod taxonomy and phylogeny, particularly for the comparative analysis of sympatric Littorina species. Observing fresh tissue and squashing fixed tissue with gradually increasing pressure, we have recently described a peculiar type of cystic spermatogenesis, rare in mollusks. It has not been documented in most mollusks until now. The testis of adult males consists of numerous lobules filled with multicellular cysts containing germline cells at different stages of differentiation. Each cyst is formed by one cyst cell of somatic origin. Here, we provide evidence for the existence of two ways of cyst formation in Littorina saxatilis. One of them begins with a goniablast cyst formation; it somewhat resembles cyst formation in Drosophila testes. The second way begins with capture of a free spermatogonium by the polyploid cyst cell which is capable to move along the gonad tissues. This way of cyst formation has not been described previously.
    [Show full text]
  • Hallucigenia's Onychophoran-Like Claws
    LETTER doi:10.1038/nature13576 Hallucigenia’s onychophoran-like claws and the case for Tactopoda Martin R. Smith1 & Javier Ortega-Herna´ndez1 The Palaeozoic form-taxon Lobopodia encompasses a diverse range of Onychophorans lack armature sclerites, but possess two types of ap- soft-bodied‘leggedworms’ known from exceptionalfossil deposits1–9. pendicular sclerite: paired terminal claws in the walking legs, and den- Although lobopodians occupy a deep phylogenetic position within ticulate jaws within the mouth cavity9,23.AsinH. sparsa, claws in E. Panarthropoda, a shortage of derived characters obscures their evo- kanangrensis exhibit a broad base that narrows to a smooth conical point lutionary relationships with extant phyla (Onychophora, Tardigrada (Fig. 1e–h). Each terminal clawsubtends anangle of130u and comprises and Euarthropoda)2,3,5,10–15. Here we describe a complex feature in two to three constituent elements (Fig. 1e–h). Each smaller element pre- the terminal claws of the mid-Cambrian lobopodian Hallucigenia cisely fills the basal fossa of its container, from which it can be extracted sparsa—their construction from a stack of constituent elements— with careful manipulation (Fig. 1e, g, h and Extended Data Fig. 3a–g). and demonstrate that equivalent elements make up the jaws and claws Each constituent element has a similar morphology and surface orna- of extant Onychophora. A cladistic analysis, informed by develop- ment (Extended Data Fig. 3a–d), even in an abnormal claw where mental data on panarthropod head segmentation, indicates that the element tips are flat instead of pointed (Extended Data Fig. 3h). The stacked sclerite components in these two taxa are homologous— proximal bases of the innermost constituent elements are associated with resolving hallucigeniid lobopodians as stem-group onychophorans.
    [Show full text]
  • Phylogeny of Hallucigenia
    Phylogeny of Hallucigenia By Annette Hilton December 4th, 2014 Invertebrate Paleontology Cover artwork from: http://people.ds.cam.ac.uk/ms609/ 2 Abstract Hallucigenia is an extinct genus from the lower-middle Cambrian. A small worm-like organism with dorsal spines, Hallucigenia is rare in fossil history, and its identity and morphology have often been confounded. Since its original discovery in the Burgess Shale by Walcott, Hallucigenia has since become an iconic fossil. Its greater systematics and place in the phylogenetic tree is controversial and not completely understood. New evidence and the discovery of additional species of Hallucigenia have contributed much to the understanding of this genus and its broader relations in classification and evolutionary history. Introduction Hallucigenia is a genus that encompasses three known species that lived during the Cambrian period—Hallucigenia sparsa, Hallucigenia fortis, and Hallucigenia hongmeia (Ma et al., 2012). Hallucigenia’s taxonomy in figure 1. Kingdom Animalia Phylum Onychophora (Lobopodia) Class Xenusia Order Scleronychophora Genus Hallucigenia Figure 1. Taxonomy of Hallucigenia species. Collectively, all Hallucigenia specimens are rare, with a portion of specimens incomplete. The understanding of Hallucigenia and its life mode has been confounded since the 3 original discovery of H. sparsa, but subsequent species discoveries has shed light on some of its mysteries (Conway Morris, 1998). Even more information concerning Hallucigenia is currently being unearthed—its classification into the phylum Onychophora and wider relations to other invertebrate groups like Arthropoda and the poorly understood Lobopodian group (Campbell et al., 2011). Hallucigenia, an iconic fossil of the Burgess Shale, demonstrates the well-known diversity of the Cambrian period, its morphology providing increasing numbers of clues to its connection into the greater systematic system.
    [Show full text]
  • Helenodora Inopinata (Carboniferous, Mazon Creek Lagerstätte) and the Onychophoran Stem Lineage Duncan J
    Murdock et al. BMC Evolutionary Biology (2016) 16:19 DOI 10.1186/s12862-016-0582-7 RESEARCH ARTICLE Open Access The impact of taphonomic data on phylogenetic resolution: Helenodora inopinata (Carboniferous, Mazon Creek Lagerstätte) and the onychophoran stem lineage Duncan J. E. Murdock, Sarah E. Gabbott and Mark A. Purnell* Abstract Background: The origin of the body plan of modern velvet worms (Onychophora) lies in the extinct lobopodians of the Palaeozoic. Helenodora inopinata, from the Mazon Creek Lagerstätte of Illinois (Francis Creek Shale, Carbondale Formation, Middle Pennsylvanian), has been proposed as an intermediate between the “weird wonders” of the Cambrian seas and modern terrestrial predatory onychophorans. The type material of H. inopinata, however, leaves much of the crucial anatomy unknown. Results: Here we present a redescription of this taxon based on more complete material, including new details of the head and posterior portion of the trunk, informed by the results of experimental decay of extant onychophorans. H. inopinata is indeed best resolved as a stem-onychophoran, but lacks several key features of modern velvet worms including, crucially, those that would suggest a terrestrial mode of life. Conclusions: The presence of H. inopinata in the Carboniferous demonstrates the survival of a Cambrian marine morphotype, and a likely post-Carboniferous origin of crown-Onychophora. Our analysis also demonstrates that taphonomically informed tests of character interpretations have the potential to improve phylogenetic resolution. Keywords: Panarthropoda, Lobopodia, Onychophora, Mazon Creek, Taphonomy Background of unequivocal terrestrial onychophorans are known from Lobopodians are extinct worm-like animals characterised Cretaceous [5] and Eocene [6, 7] amber. Helenodora inopi- by their unsegmented lobopodous limbs.
    [Show full text]
  • A Cambrian Unarmoured Lobopodian, †Lenisambulatrix Humboldti Gen. Et Sp
    www.nature.com/scientificreports OPEN A Cambrian unarmoured lobopodian, †Lenisambulatrix humboldti gen. et sp. nov., Received: 29 January 2018 Accepted: 14 August 2018 compared with new material of Published: xx xx xxxx †Diania cactiformis Qiang Ou 1,2 & Georg Mayer2 Cambrian marine lobopodians are generally considered as predecessors of modern panarthropods (onychophorans, tardigrades, and arthropods). Hence, further study of their morphological diversity and early radiation may enhance our understanding of the ground pattern and evolutionary history of panarthropods. Here, we report a rare lobopodian species, †Lenisambulatrix humboldti gen. et sp. nov. (“Humboldt lobopodian”), from the early Cambrian Chengjiang Lagerstätte and describe new morphological features of †Diania cactiformis, a coeval armoured lobopodian nicknamed “walking cactus”. Both lobopodian species were similar in possessing rather thick, elongate lobopods without terminal claws. However, in contrast to †Diania cactiformis, the body of which was heavily armored with spines, the trunk and limbs of the Humboldt lobopodian were entirely unarmored. Our study augments the morphological diversity of Cambrian lobopodians and presents two evolutionary extremes of cuticular ornamentation: one represented by the Humboldt lobopodian, which was most likely entirely “naked”, the other epitomized by †D. cactiformis, which was highly “armoured”. Lobopodians were marine, caterpillar-like Palaeozoic animals characterized by non-segmented limbs called lobo- pods or lobopodia (singular: lobopodium; from Greek λοβός [lobos], rounded projection or protuberance; and ποδός [podos], foot). Lobopodians originated and rapidly diversifed1 during the Cambrian radiation of meta- zoan body plans and their marine representatives survived at least until the end of the Carboniferous Period2. Lobopodians are generally considered as a paraphyletic assemblage because some were most likely the forerun- ners of modern lobopod-bearing animals3–5, the onychophorans and tardigrades, and their closest relatives, the arthropods.
    [Show full text]
  • A New Phyllopod Bed-Like Assemblage from the Burgess Shale of the Canadian Rockies
    ARTICLE Received 30 Dec 2013 | Accepted 7 Jan 2014 | Published 11 Feb 2014 DOI: 10.1038/ncomms4210 A new phyllopod bed-like assemblage from the Burgess Shale of the Canadian Rockies Jean-Bernard Caron1,2,3, Robert R. Gaines4,Ce´dric Aria1,2, M. Gabriela Ma´ngano5 & Michael Streng6 Burgess Shale-type fossil assemblages provide the best evidence of the ‘Cambrian explosion’. Here we report the discovery of an extraordinary new soft-bodied fauna from the Burgess Shale. Despite its proximity (ca. 40 km) to Walcott’s original locality, the Marble Canyon fossil assemblage is distinct, and offers new insights into the initial diversification of metazoans, their early morphological disparity, and the geographic ranges and longevity of many Cambrian taxa. The arthropod-dominated assemblage is remarkable for its high density and diversity of soft-bodied fossils, as well as for its large proportion of new species (22% of total diversity) and for the preservation of hitherto unreported anatomical features, including in the chordate Metaspriggina and the arthropod Mollisonia. The presence of the stem arthropods Misszhouia and Primicaris, previously known only from the early Cambrian of China, suggests that the palaeogeographic ranges and longevity of Burgess Shale taxa may be underestimated. 1 Department of Natural History-Palaeobiology, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, Canada M5S 2C6. 2 Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2. 3 Department of Earth Sciences, University of Toronto, 25 Russell Street, Toronto, Ontario, Canada M5S 3B1. 4 Geology Department, Pomona College, 185 E. Sixth Street, Claremont, California 91711, USA.
    [Show full text]
  • Whole-Body Regeneration in Sponges: Diversity, Fine Mechanisms, and Future Prospects
    G C A T T A C G G C A T genes Review Whole-Body Regeneration in Sponges: Diversity, Fine Mechanisms, and Future Prospects Alexander Ereskovsky 1,2,3,* , Ilya E. Borisenko 2 , Fyodor V. Bolshakov 4 and Andrey I. Lavrov 4 1 Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE), Aix Marseille University, CNRS, IRD, Station Marine d’Endoume, Rue de la Batterie des Lions, Avignon University, 13007 Marseille, France 2 Department of Embryology, Faculty of Biology, Saint-Petersburg State University, 199034 Saint-Petersburg, Russia; [email protected] 3 Evolution of Morphogenesis Laboratory, Koltzov Institute of Developmental Biology of Russian Academy of Sciences, 119334 Moscow, Russia 4 Pertsov White Sea Biological Station, Biological Faculty, Lomonosov Moscow State University, 119192 Moscow, Russia; [email protected] (F.V.B.); [email protected] (A.I.L.) * Correspondence: [email protected]; Tel.: +33-662-107-366 Abstract: While virtually all animals show certain abilities for regeneration after an injury, these abilities vary greatly among metazoans. Porifera (Sponges) is basal metazoans characterized by a wide variety of different regenerative processes, including whole-body regeneration (WBR). Consid- ering phylogenetic position and unique body organization, sponges are highly promising models, as they can shed light on the origin and early evolution of regeneration in general and WBR in particu- lar. The present review summarizes available data on the morphogenetic and cellular mechanisms accompanying different types of WBR in sponges. Sponges show a high diversity of WBR, which principally could be divided into (1) WBR from a body fragment and (2) WBR by aggregation of dissociated cells.
    [Show full text]
  • Int J Paleobiol & Paleontol 2018, 1(1): 000101
    International Journal of Paleobiology & Paleontology The Enlightenment of the Earliest Footprint Fossil Discovery in China Feng W* Short Communication Nanjing Institute of Geology and Palaeontology, China Volume 1 Issue 1 Received Date: August 13, 2018 *Corresponding author: Feng Weimin, Nanjing Institute of Geology and Published Date: September 03, 2018 Palaeontology, China, E-mail: [email protected] Introduction Whether the Cambrian life explosion started at the end of the Precambrian period, whether the Precambrian On June 6 this year, Science Advances published in the biota and the Cambrian biota have a gradual transitional journal Science of the United States online reported the evolutionary relationship is still controversial. One year footprints of metazoans with appendages found by ago, an international research team led by Chinese Chinese and American scientists in the Ediacaran strata of scientists published the latest advances in the Cambrian the Three Gorges area in Hubei Province, China [1]. This is explosion published in the journal of Geology [3]. Based the oldest known footprint fossil on earth. The study on the stratigraphic and paleontological fossil data found two rows of walking imprints and three burrow obtained in the Far East Siberia region of Russia, they imprints produced by bilaterian animals with paired proved that the typical fossils of the Cambrian period appendages. Studies have shown that the characteristics have appeared in the late Precambrian period and are of these imprints reflect that the migratory organisms can mixed with the skeleton weak fossils of the late support the body from the surface of the sediment Precambrian. For example, the late Precambrian typical through the appendages, while the track ways of the weakly mineralized “Cloudina Tube” fossils are symbiotic contemporaneous animals found in the past are all with the tubular and other skeleton fossils of the creeping on the surface of the sediment.
    [Show full text]
  • Downloaded from at University of Durham on November 12, 2019
    Durham Research Online Deposited in DRO: 12 November 2019 Version of attached le: Published Version Peer-review status of attached le: Peer-reviewed Citation for published item: Harper, D.A.T. and Hammarlund, E.U. and Topper, T.P. and Nielsen , A.T. and Rasmussen , J.A. and Park, T-Y.S. and Smith , M.P. (2019) 'The Sirius Passet Lagerst¤atteof North Greenland : a remote window on the Cambrian Explosion.', Journal of the Geological Society., 176 (6). pp. 1023-1037. Further information on publisher's website: https://doi.org/10.1144/jgs2019-043 Publisher's copyright statement: c 2019 The Author(s). Published by The Geological Society of London http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/) Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom Tel : +44 (0)191 334 3042 | Fax : +44 (0)191 334 2971 https://dro.dur.ac.uk Downloaded from http://jgs.lyellcollection.org/ at University of Durham on November 12, 2019 Review Focus article Journal of the Geological Society Published online July 26, 2019 https://doi.org/10.1144/jgs2019-043 | Vol.
    [Show full text]