DOCSLIB.ORG

Modeling Planarian Regeneration: a Primer for Reverse- Engineering the Worm

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Modeling Planarian Regeneration: a Primer for Reverse- Engineering the Worm Perspective Modeling Planarian Regeneration: A Primer for Reverse- Engineering the Worm Daniel Lobo, Wendy S. Beane, Michael Levin* Center for Regenerative and Developmental Biology, and Department of Biology, Tufts University, Medford, Massachusetts, United States of America chines and fault-tolerant, robust systems. Abstract: A mechanistic under- the cellular mechanisms that are A medical treatment that would enable a standing of robust self-assembly and thought to underlie them. By es- person to regenerate a completely new repair capabilities of complex systems tablishing an engineering-like style head, or a robotic system that could would have enormous implications for reviews of the molecular devel- automatically recover its proper structure for basic evolutionary developmental opmental biology of biomedically and function after losing more than 99% biology as well as for transformative important model systems, signifi- of its constitutive parts, is still only a applications in regenerative biomed- cant fresh insights and quantitative dream. However, there does exist a icine and the engineering of highly computational models will be de- natural system capable of performing these fault-tolerant cybernetic systems. Mo- veloped by new collaborations amazing feats: the planaria. lecular biologists are working to between biology and the informa- Planarians are nonparasitic flatworms identify the pathways underlying the tion sciences. remarkable regenerative abilities of that have bilateral symmetry, a true brain model species that perfectly regener- driving a complex behavioral repertoire ate limbs, brains, and other complex [2], and an extraordinary capacity to body parts. However, a profound regenerate due to the presence of a large disconnect remains between the adult stem cell population [3]. Individual deluge of high-resolution genetic Possibly the people who are trying to planarians are practically immortal—able and protein data on pathways re- discover how to set up a computer to to regenerate aging, as well as severely quired for regeneration, and the learn to play good chess, or bridge, damaged or lost, tissues [4]. A trunk desired spatial, algorithmic models are among those most likely to make fragment cut from the middle of an adult that show how self-monitoring and a major contribution to the funda- planarian will regenerate into a whole growth control arise from the synthe- worm, always growing a new head and sis of cellular activities. This barrier to mental theory of evolution. — C. H. Waddington [1] new tail in the same orientation as the progress in the understanding of original worm. As little as 1/279th of a morphogenetic controls may be planarian [5], or a fragment with as few as breached by powerful techniques 10,000 cells [6], can regenerate into a new from the computational sciences— Introduction using non-traditional modeling ap- worm within 1–2 weeks. Planaria are a proaches to reverse-engineer systems The ability to control the pattern popular model for molecular-genetic and such as planaria: flatworms with a formation of organs and appendages is a biophysical dissection of pathways that complex bodyplan and nervous sys- key aim of regenerative medicine. Trans- underlie regenerative patterning [4,7,8], tem that are able to regenerate any formative impact in areas such as birth having more genes in common with body part after traumatic injury. defects, traumatic injury, cancer, and humans than with the fruit fly Drosophila. Currently, the involvement of experts degenerative disease requires that we A mechanistic understanding of the com- from outside of molecular genetics is understand the molecular mechanisms munication and control networks that hampered by the specialist literature that allow living beings to detect and maintain complex shape against radical of molecular developmental biology: repair damage to complex biological perturbations will revolutionize our ability impactful collaborations across such structures. A similar goal is pursued by to regulate stem cell behavior in the different fields require that review engineers seeking to build resilient ma- context of the host organism. Thus, literature be available that presents the key functional capabilities of important biological model systems Citation: Lobo D, Beane WS, Levin M (2012) Modeling Planarian Regeneration: A Primer for Reverse- while abstracting away from the Engineering the Worm. PLoS Comput Biol 8(4): e1002481. doi:10.1371/journal.pcbi.1002481 often irrelevant and confusing details Editor: Takashi Gojobori, National Institute of Genetics, Japan of specific genes and proteins. To Published April 26, 2012 facilitate modeling efforts by comput- Copyright: ß 2012 Lobo et al. This is an open-access article distributed under the terms of the Creative er scientists, physicists, engineers, and Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, mathematicians, we present a differ- provided the original author and source are credited. ent kind of review of planarian Funding: This work was supported by the Telemedicine and Advanced Technology Research Center (TATRC) regeneration. Focusing on the main at the U.S. Army Medical Research and Materiel Command (USAMRMC) through award W81XWH-10-2-0058. ML patterning properties of this system, is also grateful for the support of the G. Harold and Leila Y. Mathers Charitable Foundation, and NSF CDI grant - EF-1124651. WSB gratefully acknowledges the support of the NIH Kirschstein-NRSA grant F32 GM08354. The we review what is known about the funders had no role in the preparation of the manuscript. signal exchanges that occur during regenerative repair in planaria and Competing Interests: The authors have declared that no competing interests exist. * E-mail: [email protected] PLoS Computational Biology | www.ploscompbiol.org 1 April 2012 | Volume 8 | Issue 4 | e1002481 reverse-engineering the remarkable system processes [14,15] (for excellent introduc- In this review, we hope to close the gap that is planarian regeneration would have tions to biological pattern formation mod- between regenerative biology and the profound impacts on regenerative medi- eling see [16–19]). Unlike bare gene or fields of mathematics, computer science, cine, bioengineering, synthetic biology, protein networks, such models are con- and engineering and lower the barrier for and robotics. structive in the sense that they make experts from the information and systems Regeneration in planarians involves a explicit the events that need to occur to engineering sciences to apply their knowl- truly complex interaction of several sys- create a specific shape. Only a handful of edge to unraveling the mechanisms of tems at the organismal level. After an algorithmic models have been proposed large-scale regeneration. Here we provide injury, the stem cells in the worm over the years to explain regeneration in an overview of the planarian regeneration proliferate and migrate to form a protec- planarians [20–23] (see ‘‘Existing Models’’ system, explain what is known about the tive mass of new cells (blastema) at the section below and Supplemental Text S1), signaling mechanisms, summarize the wound site. This cell proliferation is tightly and none of them successfully integrate proposed partial models in the literature, coordinated with the selective destruction more than one or two key features of and frame the specific issues that must be of some old cells (apoptosis), effectively regeneration. addressed to bring the power of interdis- remodeling both the new and old tissues to There is a gap between the success of ciplinary investigation to fruition. Our recreate exactly those regions and organs high-resolution genetic analysis and the goal is to present the basic features of this the worm is missing, adjust the propor- needed level of insight into systems-level system from an engineering perspective to tions of the remaining regions and organs mechanisms that enable adaptive control facilitate modeling approaches [35–38]. If to the new smaller worm size, and of pattern formation. A fresh set of ideas the modeling and engineering communi- maintain the original patterning orienta- may be helpful, from areas of science that ties can be engaged to produce algorith- tion of the worm with the new tissues. have developed techniques for reverse- mic models that can accurately explain These complex interactions are controlled engineering complex systems, utilizing the regeneration process, the application by a diverse set of signals, including analytical methods and types of models of biologically inspired computational molecular pathways, gap junctional com- that are distinct from those familiar to ideas will feed back into biology and aid munication, ion fluxes, and nervous sys- most cell biologists today. Construction of our understanding of complex biological tem signals. Although essential for regen- in silico implementations is especially systems [39]. Conversely, the insights eration, the mechanisms by which these crucial; for any but the most trivial set of gained from the construction and appli- signals integrate to maintain and restore relationships among subunits, running a cation of these regenerative models will the correct geometry of the animal are still simulation on a computer is the only way equally benefit computer science, artificial not well understood. to determine the predictions of a given life, robotics, and many areas of engi- After more than 100
Load more

Recommended publications
  • Manual of Experimentation in Planaria
    l\ MANUAL .OF PSYCHOLOGICAL EXPERIMENTATION ON PLANARIANS Ed;ted by James V. McConnell A MANUAL OF PSYCHOLOGICAL EXPERIMENTATI< ON PlANARIANS is a special publication of THE WORM RUNNER'S DIGEST James V. McConnell, Editor Mental Health Research Institute The University of Michigan Ann Arbor, Michigan BOARD OF CONSULTING EDITORS: Dr. Margaret L. Clay, Mental Health Research Institute, The University of Michigan Dr. WiHiam Corning, Department of Biophysics, Michigan State University Dr. Peter Driver, Stonehouse, Glouster, England Dr. Allan Jacobson, Department of Psychology, UCLA Dr. Marie Jenkins, Department of Biology, Madison College, Harrisonburg, Virginir Dr. Daniel P. Kimble, Department of Psychology, The University of Oregon Mrs. Reeva Jacobson Kimble, Department of Psychology, The University of Oregon Dr. Alexander Kohn, Department of Biophysics, Israel Institute for Biological Resear( Ness-Ziona, Israel Dr. Patrick Wells, Department of Biology, Occidental College, Los Angeles, Calif 01 __ Business Manager: Marlys Schutjer Circulation Manager: Mrs. Carolyn Towers Additional copies of this MANUAL may be purchased for $3.00 each from the Worm Runner's Digest, Box 644, Ann Arbor, Michigan. Information concerning subscription to the DIGEST itself may also be obtained from this address. Copyright 1965 by James V. McConnell No part of this MANUAL may be ;e�p� oduced in any form without prior written consen MANUAL OF PSYCHOLOGICAL EXPERIMENTATION ON PLANARIANS ·� �. : ,. '-';1\; DE DI�C A T 1 a'li � ac.-tJ.l that aILe. plle.J.le.l1te.cl iVl thiJ.l f, fANUA L [ve.lle. pUIlc.ilaJ.le.d blj ituVldlle.dJ.l 0& J.lc.ie.l1tiJ.ltJ.lo wil , '{'l1d.{.vidua"tlu aVld c.olle.c.t- c.aVlVlot be.g.{.Vl to l1ame.
    [Show full text]
  • Supplementary Material
    Supplementary Material Table S1. Characteristics of volunteer groups (student classes), according to the scholar degree (covering degrees from the 5th to the 12th years of scholarity), mean age of the students, number of teachers involved and number of students for each class. A few schools merged different classes in the same group; those cases correspond to two to three scholar degrees or two to three mean ages. Degree Mean Age Teachers Students 5th 11 3 40 12th 17 3 12 5th 11 2 20 5th 12 2 27 5th 11 3 25 7th 12 3 17 8th 13 2 20 8th 13 1 39 9th,11th,12th 16 3 66 10th 15 3 23 8th 13 1 26 10th 15 3 38 8th 13 2 12 8th 13 2 14 8th 13 1 23 9th 14 1 6 8th 13 3 23 10th 15 1 11 9th 14 1 4 7th 12 3 24 8th 13 3 23 5th .10, 11 3 20 8th 13 3 23 7th,8th 13 3 12 8th 13 3 25 10th 15 3 25 10th 15 3 25 10th 15 2 25 10th 15 2 25 11th,12th 16, 17 3 19 11th,12th 16, 18 3 19 11th,12th 16, 17 3 19 11th,12th 16, 17 3 19 8th 13 3 15 8th 13 3 23 5th .10, 11 1 20 Table S2. Categories in the field form distributed by the four main descriptors. Settlements on the State of Stream Land Use Stream the Water Characteristics tourism mures none perceptible flow natural golf tubes laminar flow intermediary camping spring turbulent flow altered agriculture well no smell Pasture channel mud smell farm mill waste smell forest dam clean water industry brown water waste water treatment plant black water (wwtp) constructions soft green water road hard green water Table S3.
    [Show full text]
  • The History and Enduring Contributions of Planarians to the Study of Animal Regeneration Sarah A
    Advanced Review The history and enduring contributions of planarians to the study of animal regeneration Sarah A. Elliott1,2 and Alejandro Sanchez´ Alvarado1,2∗ Having an almost unlimited capacity to regenerate tissues lost to age and injury, planarians have long fascinated naturalists. In the Western hemisphere alone, their documented history spans more than 200 years. Planarians were described in the early 19th century as being ‘immortal under the edge of the knife’, and initial investigation of these remarkable animals was significantly influenced by studies of regeneration in other organisms and from the flourishing field of experimental embryology in the late 19th and early 20th centuries. This review strives to place the study of planarian regeneration into a broader historical context by focusing on the significance and evolution of knowledge in this field. It also synthesizes our current molecular understanding of the mechanisms of planarian regeneration uncovered since this animal’s relatively recent entrance into the molecular-genetic age. © 2012 Wiley Periodicals, Inc. How to cite this article: WIREs Dev Biol 2012. doi: 10.1002/wdev.82 PLANARIANS AND THEIR HISTORICAL development, epigenesis eventually took center stage CONTEXT as one of the most important principles of biology.1 The earliest known description of animal regen- he study of regeneration has a rich, intertwined eration came from Aristotle around 350 BCE. Among Thistory with experimental embryology. In the other things, he described that the tails of lizards 17th century, naturalists contemplated two ancient regenerate.2 In 1686, Thevenot,´ Perrault, and Duver- paradigms for thinking about embryology: preforma- ney revived this finding.3 This rediscovery of regener- tionism versus epigenesis.
    [Show full text]
  • The Effect of Caffeine and Ethanol on Flatworm Regeneration
    East Tennessee State University Digital Commons @ East Tennessee State University Electronic Theses and Dissertations Student Works 8-2007 The ffecE t of Caffeine nda Ethanol on Flatworm Regeneration. Erica Leighanne Collins East Tennessee State University Follow this and additional works at: https://dc.etsu.edu/etd Part of the Chemical and Pharmacologic Phenomena Commons Recommended Citation Collins, Erica Leighanne, "The Effect of Caffeine nda Ethanol on Flatworm Regeneration." (2007). Electronic Theses and Dissertations. Paper 2028. https://dc.etsu.edu/etd/2028 This Thesis - Open Access is brought to you for free and open access by the Student Works at Digital Commons @ East Tennessee State University. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Digital Commons @ East Tennessee State University. For more information, please contact [email protected]. The Effect of Caffeine and Ethanol on Flatworm Regeneration ____________________ A thesis presented to the faculty of the Department of Biological Sciences East Tennessee State University In partial fulfillment of the requirements for the degree Master of Science in Biology ____________________ by Erica Leighanne Collins August 2007 ____________________ Dr. J. Leonard Robertson, Chair Dr. Thomas F. Laughlin Dr. Kevin Breuel Keywords: Regeneration, Planarian, Dugesia tigrina, Flatworms, Caffeine, Ethanol ABSTRACT The Effect of Caffeine and Ethanol on Flatworm Regeneration by Erica Leighanne Collins Flatworms, or planarian, have a high potential for regeneration and have been used as a model to investigate regeneration and stem cell biology for over a century. Chemicals, temperature, and seasonal factors can influence planarian regeneration. Caffeine and ethanol are two widely used drugs and their effect on flatworm regeneration was evaluated in this experiment.
    [Show full text]
  • Platyhelminthes: Tricladida: Terricola) of the Australian Region
    ResearchOnline@JCU This file is part of the following reference: Winsor, Leigh (2003) Studies on the systematics and biogeography of terrestrial flatworms (Platyhelminthes: Tricladida: Terricola) of the Australian region. PhD thesis, James Cook University. Access to this file is available from: http://eprints.jcu.edu.au/24134/ The author has certified to JCU that they have made a reasonable effort to gain permission and acknowledge the owner of any third party copyright material included in this document. If you believe that this is not the case, please contact [email protected] and quote http://eprints.jcu.edu.au/24134/ Studies on the Systematics and Biogeography of Terrestrial Flatworms (Platyhelminthes: Tricladida: Terricola) of the Australian Region. Thesis submitted by LEIGH WINSOR MSc JCU, Dip.MLT, FAIMS, MSIA in March 2003 for the degree of Doctor of Philosophy in the Discipline of Zoology and Tropical Ecology within the School of Tropical Biology at James Cook University Frontispiece Platydemus manokwari Beauchamp, 1962 (Rhynchodemidae: Rhynchodeminae), 40 mm long, urban habitat, Townsville, north Queensland dry tropics, Australia. A molluscivorous species originally from Papua New Guinea which has been introduced to several countries in the Pacific region. Common. (photo L. Winsor). Bipalium kewense Moseley,1878 (Bipaliidae), 140mm long, Lissner Park, Charters Towers, north Queensland dry tropics, Australia. A cosmopolitan vermivorous species originally from Vietnam. Common. (photo L. Winsor). Fletchamia quinquelineata (Fletcher & Hamilton, 1888) (Geoplanidae: Caenoplaninae), 60 mm long, dry Ironbark forest, Maryborough, Victoria. Common. (photo L. Winsor). Tasmanoplana tasmaniana (Darwin, 1844) (Geoplanidae: Caenoplaninae), 35 mm long, tall open sclerophyll forest, Kamona, north eastern Tasmania, Australia.
    [Show full text]
  • Classification Notes (Updated 2013).Pdf
    Study of Life Classification The Amazing Diversity of LIFE!!!! • Diversity of Life – There are so many different creatures on Earth – Why are there differences? • Unity of life – All creatures have similarities – Common characteristics – Why are they so alike? Biology 2011-12 The Amazing Diversity of LIFE!!!! Biology 2011-12 Classifying Life • The Tree of Life – Organize creatures by structure & function • How they are built • How they live – Organize them into groups of closely related creatures Biology 2011-12 Eukaryote Classifying Life • 6 Kingdom system – Prokaryotes Prokaryote • No separate organelles in their cells • Ex. Bacteria • Ex. Archaebacteria – Eukaryotes • Separate organelles in their cells • Ex. Protists • Ex. Plants • Ex. Fungi • Ex. Animals Bacteria & Biology Archaebacteria 2011 -12 Prokaryotes Classifying Life Kingdom Kingdom Kingdom Bacteria Archaebacteria Protist Eukaryotes Kingdom Kingdom Kingdom Fungi Plant Animal Biology 2011-12 Classifying Life . Kingdom . Phylum . Class . Order . Family . Genus . species Biology 2011-12 Science History Moment • Carolus Linnaeus (1707-1778) . “Father of Modern Taxonomy” . Swedish botanist . Took complex system and simplified • Binomial nomenclature . Every organism has two names (in Latin- WHY?): — Genus name: noun — Species name: adjective • Published: Systema Naturae in 1735 . Reclassified plants using his binomial system (bi= two, nomial= name, two word naming) Biology 2011-12 Scientific Names • Standard Format . Every scientific name begins with the genus . Genus is capitalized
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE Jochen C. Rink Director Department of Tissue Dynamics and Regeneration Max Planck Institute for Biophysical Chemistry Am Fassberg 11 I 37077 Göttingen I Germany E-mail: [email protected] Tel: +49 551 201 26100 Web: www.mpibpc.mpg.de/rink Birth date: October 18th, 1976 RESEARCH EXPERIENCE 2019- Director Max Planck Institute for Biophysical Chemistry in Göttingen, Germany 2011 - 2019 Independent Max Planck Research Group Leader Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany Distinctions: Awarded a Max “Free Floater” position with 2 competitive renewals since 2012 Affiliate Centre of Regenerative Therapies CRTD, Dresden, Germany 2006 – 2011 Postdoctoral Research Howard Hughes Institute, University of Utah, Salt Lake City, UT, USA EDUCATION 2005 Ph.D. Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany Grade: Summa cum laude Distinctions: Awarded the Max Planck-Society’s Otto Hahn Medal for outstanding thesis 2000 Bachelor of Arts Christ’s College, Cambridge University, Cambridge, UK Grade: First Class Honours Distinctions: SW Greig-Price for academic excellence in Natural Sciences: 98, 99 and 2000 AWARDS AND FELLOWSHIPS 2020 Deutsche Forschungsgemeinschaft award 2020 Behrens-Weise foundation award 1 2018 VolkswagenStiftung award 2015 EMBO Young Investigator award 2015 ERC Consolidator grant 2011 Max Planck Research Group 2006 EMBO Postdoctoral fellowship 2005 Otto Hahn Medal of the Max Planck Society for outstanding thesis research ORGANISATION OF SCIENTIFIC MEETINGS 2018 Organizer, EMBO workshop on “Size and Shape”, at NCBS in Bangalore, India 2018 Co-organizer, “3rd International Planarian Meeting”, Wisconsin, Madison, USA 2018 Co-organizer, EMBO YIP sectorial meeting on Morphogenesis, Marseille, France 2016 Organizer, “3nd European meeting on Planarian Biology”, St.
    [Show full text]
  • Resolving a 200-Year-Old Taxonomic Conundrum: Neotype Designation for Cephalothrix Linearis (Nemertea: Palaeonemertea) Based on a Topotype from Bergen, Norway
    Fauna norvegica 2019 Vol. 39: 39–76. Resolving a 200-year-old taxonomic conundrum: neotype designation for Cephalothrix linearis (Nemertea: Palaeonemertea) based on a topotype from Bergen, Norway Hiroshi Kajihara1 Kajihara H. 2019. Resolving a 200-year-old taxonomic conundrum: neotype designation for Cephalothrix linearis (Nemertea: Palaeonemertea) based on a topotype from Bergen, Norway. Fauna norvegica 39: 39–76. The taxonomic identity of the palaeonemertean Cephalothrix linearis (Rathke, 1799) has been obscure for nearly two centuries, because its original description applies to almost any congeners, including Cephalothrix filiformis (Johnston 1828) and Cephalothrix rufifrons (Johnston, 1837), which occur commonly in the North Sea and adjacent waters. In this paper, I redescribe C. linearis based on two topotypes from Bergen, one herein designated as the neotype for C. linearis, because Rathke’s original material is not extant; I invoke Article 70.3.2 of the International Code of Zoological Nomenclature to fix Planaria linearis Rathke, 1799 as the type species of Cephalothrix Örsted, 1843 for the sake of stability. From the neotype, I determined sequences of the 28S rRNA, 16S rRNA, and cytochrome c oxidase subunit I (COI) genes. Using the COI sequence, I inferred the phylogenetic position of C. linearis along with 316 cephalotrichid sequences currently available in public databases. A tree-based species delimitation analysis detected 43 entities among them, with 34 in Cephalothrix and nine in either Balionemertes or Cephalotrichella.
    [Show full text]
  • Planarians, a Neglected Component of Biodiversity in Groundwaters
    diversity Article Planarians, a Neglected Component of Biodiversity in Groundwaters Benedetta Barzaghi 1,2,* , Davide De Giorgi 1, Roberta Pennati 1 and Raoul Manenti 1,2 1 Department of Environmental Science and Policy, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy; [email protected] (D.D.G.); [email protected] (R.P.); [email protected] (R.M.) 2 Laboratorio di Biologia Sotterranea “Enrico Pezzoli”, Parco Regionale del Monte Barro, Località Eremo, 23851 Galbiate, Italy * Correspondence: [email protected] Abstract: Underground waters are still one of the most important sources of drinking water for the planet. Moreover, the fauna that inhabits these waters is still little known, even if it could be used as an effective bioindicator. Among cave invertebrates, planarians are strongly suited to be used as a study model to understand adaptations and trophic web features. Here, we show a systematic literature review that aims to investigate the studies done so far on groundwater-dwelling planarians. The research was done using Google Scholar and Web of Science databases. Using the key words “Planarian cave” and “Flatworm Cave” we found 2273 papers that our selection reduced to only 48, providing 113 usable observations on 107 different species of planarians from both groundwaters and springs. Among the most interesting results, it emerged that planarians are at the top of the food chain in two thirds of the reported caves, and in both groundwaters and springs they show a high variability of morphological adaptations to subterranean environments. This is a first attempt to review the phylogeny of the groundwater-dwelling planarias, focusing on the online literature.
    [Show full text]
  • Not Your Father's Planarian: a Classic Model Enters The
    REVIEWS NOT YOUR FATHER’S PLANARIAN: A CLASSIC MODEL ENTERS THE ERA OF FUNCTIONAL GENOMICS Phillip A. Newmark* and Alejandro Sánchez Alvarado‡ Freshwater planarians were a classic model for studying the problems of development and regeneration. However, as attention shifted towards animals with more rigid developmental processes, the planarians, with their notoriously plastic ontogeny, declined in significance as a model system. This trend was exacerbated with the introduction of genetic and molecular approaches, which did not work well in planarians. More recently, the heightened interest in stem- cell biology, along with the successful application of molecular, cellular and genomic approaches in planarians, is re-establishing these fascinating organisms as models for studying regeneration and developmental plasticity. PLURIPOTENCY Among the recent triumphs of molecular biology are organisms should therefore offer important insights The ability of a cell to contribute the elucidation of many of the basic mechanisms that into stem-cell biology and the emerging field of regener- to multiple tissues in a underlie embryonic development, and the demonstra- ative medicine. developing organism. If a cell is tion that these mechanisms have been strikingly con- The tremendous strides made in understanding able to contribute to all tissues, it is said to be totipotent. served between widely divergent species. Given that embryogenesis have been driven largely by genetic Abraham Trembley’s investigations of regeneration in approaches using model systems that are amenable to Hydra (published in his Mémoires in 1744) launched classical genetic analysis. Unfortunately, these model the era of experimental biology1, it is ironic that the organisms have either limited regenerative abilities problem of regeneration still awaits a satisfying mecha- (Drosophila imaginal discs, mouse and zebrafish) or nistic explanation.
    [Show full text]
  • Zoology Unit 1: Introduction to Zoology and Evolution Grade Level: 11-12
    Subject: Zoology Unit 1: Introduction to Zoology and Evolution Grade Level: 11-12 Designed by: Maria O'Boyle School District: Tunkhannock Area School: High School Brief Summary of Unit: Zoology is the scientific study of animals. Over 600 million years of history demonstrates extensive and ongoing change, or evolution. All living things must evolve to survive. Unit 1: Introduction to Zoology and Evolution Section 1: Introduction to Zoology BIO.B.4.2.1 Describe how energy flows through an ecosystem (e.g., food chains, food webs, energy pyramids). Materials & Resources BIO.B.4.2.2 Describe biotic interactions in an ecosystem (e.g., competition, predation, symbiosis). 3.1.10.A6. Identify the advantages of multi-cellularity in organisms. 3.1.12.A2. Evaluate how organisms must derive energy from their environment or their food in order to survive. 3.1.12.A5. Analyze how structure is related to function at all levels of biological organization from molecules to organisms. 3.1.12.A6. Analyze how cells in different tissues/organs are specialized to perform specific functions. 3.1.12.A8. CHANGE AND CONSTANCY Describe and interpret dynamic changes in stable systems. Overarching Understanding: ● Animals are complex organisms that interact with biotic and abiotic parts of their ecosystems. In order to understand relationships among animals more clearly, one must understand the classification of animals. Topical Understandings Essential Questions • Zoology is a field of science that studies the Animal • What is Zoology? Kingdom. • What are the characteristics of animals? • Members of the Animal Kingdom possess unique • What is Taxonomy? characteristics that are used to classify them.
    [Show full text]
  • A Biological Survey of a Subterranean Stream: Sullivan Cave, Lawrence County, Indiana
    ABSTRACT A BIOLOGICAL SURVEY OF A SUBTERRANEAN STREAM: SULLIVAN CAVE, LAWRENCE COUNTY, INDIANA by David Lawrence Weingartner Sullivan Cave, one of the largest caves in southern Indiana, con- tains a recently-discovered subterranean stream. From August, 1961, to May, 1962, a survey was made to determine the organisms present in the stream passages, and to determine some of the physical and chemical conditions under which these organisms lived. The cave lies under a ridge with poorly-deve10ped surface drain- age; most of the water seeps through the soil, penetrates fractures in the limestone bedrock, and combines to form the subterranean stream. The stream flow varied from 3.5 to 1000 gallons per second during the course of the study. The following four stations for chemical determinations and biological collections were established: 1) a riffle and pool of the main cave stream, 2) a semi-isolated pool of the flood passage, 3) a rivulet of seepage water entering a fissure in the limestone, and 4) a surface stream overlying the cave. Standard methods were used in the physical and chemical analyses. The water temperature of the cave stream varied from 53 to 56 degrees Fahrenheit during the period of the investigation. Dissolved oxygen varied from a low of 7.4 p.p.m. in the flood passage pool to a high of 11.8 p.p.m. in the seepage water. Methyl Orange alkalinity varied from 43 p.p.m. in the seepage water to 186 p.p.m. in the main cave stream. No phenolphthalein alkalinity was observed. x I) .
    [Show full text]