DOCSLIB.ORG

Food-Reactions of Pelomyxa Carolinensis Wilson

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Food-Reactions of Pelomyxa Carolinensis Wilson AUTHORS ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOQRAPHIC SERVICE NOVEMBER 3. FOOD-REACTIONS OF PELOMYXA CAROLINENSIS WILSON WM. A. KEPNER AND J. GRAHAM EDWARDS University of Virginia FOURTEEN FIGURES C 0N T E N T S I. Introduction.. ....................... 11. Observations.,....................... A. Reactions to objects without associated currents of water-not capable of retreat.. ........................................ 383 1) Objects giving off oxygen. 2) Objects giving off carbon dioxide. B. Reactions to objects producing currents in water-capable of re- treat ....................................................... 385 1) General examples. 2) Example of change of physiological state on the part of both Pelomyxa and it.s prospective prey. 3) Reversal of reaction. 111. Discussion.. ................................................ IV. Summary ............................................................ 398 INTRODUCTION All food reactions of Pelomyxa involve movement. Ver- worn, Rhumbler, Loeb and others have seen in the analogy be- tween certain surface tension phenomena and the locomotion of Rhizopoda suggested experiments of t’he manner in which certain Lobosa travel. Dellinger (’06) and Jennings (’06), however, found that the movements of amoebae could not be interpreted so as to be explained in this wav. Jennings (’06) says: “As our account shows, most amoebae do not move at all as do liquid drops whose movements are produced through changes in surface tension,” page 5. Quite recently Mast and Root (’16) in an ingenious fashion have been able to show that surface tension is probably at best an insignificant factor in the process of feeding in amoeba,” page 48. 381 382 WM. A. KEPNER AND J. GRAHAM EDWARDS Wilson (’00)says : ‘‘ Occasionally a Pelomyxa was observed in the remarkable attitude shown in figure 5, a portion of the body resting on the bottom, while the rest of the animal divided into pseudopodia projected freely upward in the water. In this condition, Pelomyxa appears for the time being as an attached rhizopod with tentacle-like pseudopods, the nearest analogue to which is the interesting minute form, Hplamoeba sessilis, found by Frensel in Cordovn, in Argentina.” In this connection Wilson shows in his figures variously curved regions of the body, which suggest that there might have been local torsion or bending. Such torsion was observed by Mr. Conway Zirkle in this laboratory. He saw a specimen “sway one of its longer pseudopods through an arc of nearly 90 degrees back toward the thickcr region of the body. There was no percep- tible flow of the endoplasm in this pseudopod.” Oric of us has observed an arched specimen attached at its two ends standing with the plane of the arch at right angles to the surface. This attitude has been described by Wilson (’00). But in this case, the animal swayed to and fro upon the two bases of the arch, so that at one end of the oscillation it lay with the plane of the arch horizontal and directed toward the right, then after swaying through 180”, the plane of the arch lay horizontal and directed towards the left. More re- markable than this, however, has been the behavior of the specimen which was fixed by one pseudopod such as Wilson (’00) described. This specimen, standing upon the end of its body with its free end bearing three stout pseudopods, had its free end turn so as to inscribe a circular orbit countu-clock- wise. These observations indicate a differential contraction of the protoplasm, most likely the ectoplasm, which approxi- mates muscular activity and could scarcely be explained in terms of surface tension. There are obviously two classes of stimuli-chemical and physical-concerned in the response of rhizopoda to food. When, for example, an amoeba reacts to a desmid, that lies in the light, the stimulus arises from the oxygen and other ele- ments or compounds given off by the plant’s metabolism. On FOOD-REACTIONS OF PEL0,MYXA 383 the other hand a ciiiated object may produce physical stimula- tion through currents set up in the water as well as causing stimulation through the products of its metabolism. Schaeff er indicates that mere physical stimuli are responded to by amoeba. Schaeffer, (,l2), says : “All sorts of particles, whether digestible or not, are eaten if properly agitated. Not only is it unneces- sary for the agitated particle to lie in contact with the amoeba, but vibrations produced by a needle are likewise reacted to positively, if the needle point is one-fiftieth of a millimeter or more from the amoeba. We may be certain, therefore, that water vibrations proceeding from a definitely localized source are an efficient cause for successful feeding,” page 60. As a rule, the reactions of Pelomyxa to food fall into two general types. These types arise out of the non-motility or motility of the prey-the possibility of escape of the latter presenting a contingrncy, which to be successfully met, has led to a definite type of reaction. Great variability of reaction to food has been observed in Amoeba proteus hy Kepner and Taliaferro (,16), though but two classes of stimulation, concerned in the reaction of a rhizo- pod to food, can be recognized. We shall record at this point the following examples of the first type of food reactions. These descriptions of Pelomyxa’s behavior are taken from notes which were made at the time of observation by the authors and others who happened to take turns with us at the microscope as the reactions progressed. OBSERVATIONS A. Reactions to objects not capable of retreat November 4, 1916. A Pelomyxa moving in the direction of a green Eromosphaera encountered the spherical alga ec- centrically so as to turn it counter-clock-wise (as seen under the compound microscope) through about ten degrees. The Eromosphaera was not moved farther than this. The tip of the Pelomyxa’s pseudopod next expanded to fit intimately the 384 WM. A. KEPNER AND J. GRAHAM EDWARDS contour of the algal cell. This process continued until either a cup or an over arching of the Rhizopod’s protoplasm had advanced to the contour a-figure 1. The margin a then ad- vanced to contour b and beyond to margins c and c’ which had fused, bringing the spherical green cell within a closely fitting food vacuole. Within five minutes the Eromosphaera was rejected by the Pelomyxa. November 13, 1916. The specimen shown here reacting to two desmids, had taken through its dorsal surface two days previously a chilomonas and had unsuccessfully reacted to Paramaecium caudatum. This Pelomyxa came in contact with two rounded, green desmids A and B. Each desmid was then intimately surrounded and carried into the cytoplasm (fig. 2). Within five minutes, however, B was thrown out as 1 leaving a bi-forked cytoplasmic projection from which it had been dropped. Within ten minutes A had been ejected at 2 leaving a distinct cytoplasmic pocket as shown. In the above examples we have instances of Pelomyxas hav- ing ingested non-motile plants, which were giving off oxygen. These plants were sooner or later rejected; but this is not al- ways the case as the following observation shows. November 7, 1916. Messrs. F. L. Foster and C. Zirkle al- ternated with us in observing ‘a specimen that had been in a hanging drop containing long desmids and Euglenas. This specimen was pushing three non-motile Euglenas ahead of it and gliding by a fourth with which it was in contact. One of the Euglenas was ingested and retained. November 27, 1916. A specimen was travelling along in the direction of the two pseudopods 1 and 1’ as indicated by the arrows (fig. 3). Pseudopodl’ came in contact with a rounded bacterial mass within which were two kinds of ciliates. The longer type of ciliate was about the size of Loxocephalus granu- losus, but for these we had no time in which to determine the genera and species. When this contact with the mass of bacteria andof ciliat,es was made, a reversal of the course of pseudopod 1 occurred as indicated by arrow 2 and pseudopod 3 grew out over (above) the bacterial glcea and in this way ex- FOOD-REACTIONS OF PELOMYXA 385 erted enough pressure to cause one of the large ciliates to leave the glcea and swim beneath the body of Pelomyxa as indicated by the line 4. At 4-a it had escaped and a curtain of proto- plasm was thrown above it, driving it back beneath the body proper of Pelomyxa, from which it finally escaped along the path leading to the head-end of line 4. In the meantime pseudopods 1’ and 3 advanced around the sides and over the bact,erial glcea causing it to be stretched into a bi-lobed mass, the smaller lobe being squeezed out of the constricting region between the bases of the pseudopods. This smaller mass, con- taining two of the larger and nine of the smaller ciliates was eventually, completely constricted and rejected. The larger mass of the glcea was for the most part ingested by the means of the pseudopods 5 and 6’ (fig. 4) encircling about it as indicated by the contours 6 and 6’. As the tips of 6 and 6’ approached and fused, a minute mass of glcea containing one large and two small ciliates was constricted. Two portions of the original ciliate-containing glcea were thus at 11.20 a.m. rejected and the third and largest mass was ingested. After this largest mass had been ingested it was broken into small spheroidal masses, each of which was now contained in a separate food vacuole. At 12.15 p.m. the animal was just leaving the two rejected balls of bacterial glcea and showed many food vacuoles within which were active ciliates.
Load more

Recommended publications
  • Ptolemeba N. Gen., a Novel Genus of Hartmannellid Amoebae (Tubulinea, Amoebozoa); with an Emphasis on the Taxonomy of Saccamoeba
    The Journal of Published by the International Society of Eukaryotic Microbiology Protistologists Journal of Eukaryotic Microbiology ISSN 1066-5234 ORIGINAL ARTICLE Ptolemeba n. gen., a Novel Genus of Hartmannellid Amoebae (Tubulinea, Amoebozoa); with an Emphasis on the Taxonomy of Saccamoeba Pamela M. Watsona, Stephanie C. Sorrella & Matthew W. Browna,b a Department of Biological Sciences, Mississippi State University, Mississippi State, Mississippi, 39762 b Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, Mississippi, 39762 Keywords ABSTRACT 18S rRNA; amoeba; amoeboid; Cashia; cristae; freshwater amoebae; Hartmannella; Hartmannellid amoebae are an unnatural assemblage of amoeboid organisms mitochondrial morphology; SSU rDNA; SSU that are morphologically difficult to discern from one another. In molecular phy- rRNA; terrestrial amoebae; tubulinid. logenetic trees of the nuclear-encoded small subunit rDNA, they occupy at least five lineages within Tubulinea, a well-supported clade in Amoebozoa. The Correspondence polyphyletic nature of the hartmannellids has led to many taxonomic problems, M.W. Brown, Department of Biological in particular paraphyletic genera. Recent taxonomic revisions have alleviated Sciences, Mississippi State University, some of the problems. However, the genus Saccamoeba is paraphyletic and is Mississippi State, MS 39762, USA still in need of revision as it currently occupies two distinct lineages. Here, we Telephone number: +1 662-325-2406; report a new clade on the tree of Tubulinea, which we infer represents a novel FAX number: +1 662-325-7939; genus that we name Ptolemeba n. gen. This genus subsumes a clade of hart- e-mail: [email protected] mannellid amoebae that were previously considered in the genus Saccamoeba, but whose mitochondrial morphology is distinct from Saccamoeba.
    [Show full text]
  • A Revised Classification of Naked Lobose Amoebae (Amoebozoa
    Protist, Vol. 162, 545–570, October 2011 http://www.elsevier.de/protis Published online date 28 July 2011 PROTIST NEWS A Revised Classification of Naked Lobose Amoebae (Amoebozoa: Lobosa) Introduction together constitute the amoebozoan subphy- lum Lobosa, which never have cilia or flagella, Molecular evidence and an associated reevaluation whereas Variosea (as here revised) together with of morphology have recently considerably revised Mycetozoa and Archamoebea are now grouped our views on relationships among the higher-level as the subphylum Conosa, whose constituent groups of amoebae. First of all, establishing the lineages either have cilia or flagella or have lost phylum Amoebozoa grouped all lobose amoe- them secondarily (Cavalier-Smith 1998, 2009). boid protists, whether naked or testate, aerobic Figure 1 is a schematic tree showing amoebozoan or anaerobic, with the Mycetozoa and Archamoe- relationships deduced from both morphology and bea (Cavalier-Smith 1998), and separated them DNA sequences. from both the heterolobosean amoebae (Page and The first attempt to construct a congruent molec- Blanton 1985), now belonging in the phylum Per- ular and morphological system of Amoebozoa by colozoa - Cavalier-Smith and Nikolaev (2008), and Cavalier-Smith et al. (2004) was limited by the the filose amoebae that belong in other phyla lack of molecular data for many amoeboid taxa, (notably Cercozoa: Bass et al. 2009a; Howe et al. which were therefore classified solely on morpho- 2011). logical evidence. Smirnov et al. (2005) suggested The phylum Amoebozoa consists of naked and another system for naked lobose amoebae only; testate lobose amoebae (e.g. Amoeba, Vannella, this left taxa with no molecular data incertae sedis, Hartmannella, Acanthamoeba, Arcella, Difflugia), which limited its utility.
    [Show full text]
  • Bio219 Student Webpage
    Bio219 Student Webpage Bio219 Home Oh! The Chaos the Chaos! It is after all, an amoebae eat amoebae world! Jaime Avery ‘04 [email protected] Web Accessible November 30, 2003 Abstract Introduction Materials and Methods Results Conclusion Bibliography Collaborators Useful Links ABSTRACT Phospholipid membranes of amoebae Pelomyxa carolinensis were stained with FM1-43 and examined using fluorescence microscopy. The stained membrane was shown to label the lipid membrane of post stained phagosomes within pelomyxa. The FM1- 43 was used in fluorescence microscopy to demonstrate the rate of formation of phagosomes in Pelomyxa under various fed states. Phagosomes were shown to be more numerous in the Pelomyxa that had been deprived of a food source for an extended period of time than the Pelomyxa with a consistent food source. Abstract Introduction Materials and Methods Results Conclusion Bibliography Collaborators Useful Links INTRODUCTION Pelomyxa carolinensis belong to the Protista kingdom. Protists are heterotrophs (Farabee, 2001). Heterotrophs consume external food sources to acquire energy for the processes of cell motility, mitosis, organelle production, and endocytosis. Because Pelomyxa depend on external food sources for energy, they are believed to respond to a deprived food environment by increasing the rate of phagocytosis when in the presence of food. As unicellular organisms, the cytoplasms of Protists are confined by impermeable phospholipid bilayers (Farabee, 2001). During the process of endocytosis, the membrane of the Protist extends or contracts while engulfing particles from the cell’s exterior. Endocytosis includes pinocytosis and phagocytosis. Pinocytosis and phagocytosis vary with respect to engulfed particle size; phagocytosis refers to cell “eating” while pinocytosis refers to cell “drinking” (Cooper, 2004).
    [Show full text]
  • Diptera: Sciaroidea Incertae Sedis), with Description of Three New Species from India and Vietnam
    ACTA ENTOMOLOGICA MUSEI NATIONALIS PRAGAE Published 15.xii.2014 Volume 54(2), pp. 729–739 ISSN 0374-1036 http://zoobank.org/urn:lsid:zoobank.org:pub:8FF046B2-6267-454D-8A28-9AE80CC0F23C Notes on Nepaletricha (Diptera: Sciaroidea incertae sedis), with description of three new species from India and Vietnam Heikki HIPPA1) & Jan ŠEVýÍK2) 1) Gribbylunds allé 2, SE-183 65 Täby, Sweden; e-mail: [email protected] 2) Department of Biology and Ecology, University of Ostrava, Chittussiho 10, CZ-71000 Ostrava, Czech Republic; e-mail: [email protected] Abstract. The following new species are described: Nepaletricha dembickyi sp. nov. (India), N. lobosa sp. nov. (Vietnam) and N. sigma sp. nov. (India). The sys- tematic position of the genus is brieÀ y discussed. A key to the six known species of Nepaletricha is given. Key words. Insecta, Diptera, Sciaroidea, Antefungivoridae, Pleciomimidae, Rangomaramidae, Heterotricha group, Nepaletricha, fungus gnats, taxonomy, key, Oriental Region Introduction The genus Nepaletricha was established by CHANDLER (2002) for a single Oriental species Nepaletricha mystica Chandler, 2002. Subsequently, HIPPA et al. (2009) re-characterized the genus and added two new species from northern Thailand and Vietnam, respectively. The genus was considered as Sciaroidea incertae sedis by CHANDLER (2002) and HIPPA & VILKAMAA (2005, 2006). AMORIM & RINDAL (2007) placed Nepaletricha in the family Rangomaramidae, together with many other earlier unplaced genera of Sciaroidea. Concerning Nepaletricha, HIPPA et al. (2009) followed this placement. The classi¿ cation of AMORIM & RINDAL (2007) was strongly criticized by JASCHHOF (2011) who did not accept the new concept of Rangomara- midae and suggested to continue using Sciaroidea incertae sedis for a number of problematic genera of Sciaroidea.
    [Show full text]
  • Conicocassis, a New Genus of Arcellinina (Testate Lobose Amoebae)
    Palaeontologia Electronica palaeo-electronica.org Conicocassis, a new genus of Arcellinina (testate lobose amoebae) Nawaf A. Nasser and R. Timothy Patterson ABSTRACT Superfamily Arcellinina (informally known as thecamoebians or testate lobose amoebae) are a group of shelled benthic protists common in most Quaternary lacus- trine sediments. They are found worldwide, from the equator to the poles, living in a variety of fresh to brackish aquatic and terrestrial habitats. More than 130 arcellininid species and strains are ascribed to the genus Centropyxis Stein, 1857 within the family Centropyxidae Jung, 1942, which includes species that are distinguished by having a dorsoventral-oriented and flattened beret-like test (shell). Conicocassis, a new arcel- lininid genus of Centropyxidae differs from other genera of the family, specifically genus Centropyxis and its type species C. aculeata (Ehrenberg, 1932), by having a unique test comprised of two distinct components; a generally ovoid to subspherical, dorsoventral-oriented test body, with a pronounced asymmetrically positioned, funnel- like flange extending from a small circular aperture. The type species of the new genus, Conicocassis pontigulasiformis (Beyens et al., 1986) has previously been reported from peatlands in Germany, the Netherlands and Austria, as well as very wet mosses and aquatic environments in High Arctic regions of Europe and North America. The occurrence of the species in lacustrine environments in the central Northwest Ter- ritories extends the known geographic distribution of the genus in North America con- siderably southward. Nawaf A. Nasser. Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada. [email protected] R. Timothy Patterson.
    [Show full text]
  • Protists – a Textbook Example for a Paraphyletic Taxon
    ARTICLE IN PRESS Organisms, Diversity & Evolution 7 (2007) 166–172 www.elsevier.de/ode Protists – A textbook example for a paraphyletic taxon$ Martin Schlegela,Ã, Norbert Hu¨lsmannb aInstitute for Biology II, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany bFree University of Berlin, Institute of Biology/Zoology, Working group Protozoology, Ko¨nigin-Luise-Straße 1-3, 14195 Berlin, Germany Received 7 September 2004; accepted 21 November 2006 Abstract Protists constitute a paraphyletic taxon since the latter is based on the plesiomorphic character of unicellularity and does not contain all descendants of the stem species. Multicellularity evolved several times independently in metazoans, higher fungi, heterokonts, red and green algae. Various hypotheses have been developed on the evolution and nature of the eukaryotic cell, considering the accumulating data on the chimeric nature of the eukaryote genome. Subsequent evolution of the protists was further complicated by primary, secondary, and even tertiary intertaxonic recombinations. However, multi-gene sequence comparisons and structural data point to a managable number of such events. Several putative monophyletic lineages and a gross picture of eukaryote phylogeny are emerging on the basis of those data. The Chromalveolata comprise Chromista and Alveolata (Dinoflagellata, Apicomplexa, Ciliophora, Perkinsozoa, and Haplospora). Major lineages of the former ‘amoebae’ group within the Heterolobosa, Cercozoa, and Amoebozoa. Cercozoa, including filose testate amoebae, chlorarachnids, and plasmodiophoreans seem to be affiliated with foraminiferans. Amoebozoa consistently form the sister group of the Opisthokonta (including fungi, and with choanoflagellates as sister group of metazoans). A clade of ‘plants’ comprises glaucocystophytes, red algae, green algae, and land vascular plants. The controversial debate on the root of the eukaryote tree has been accelerated by the interpretation of gene fusions as apomorphic characters.
    [Show full text]
  • Protistology Structure and Development of Pelomyxa Gruberi
    Protistology 4 (3), 227244 (2006) Protistology Structure and development of Pelomyxa gruberi sp. n. (Peloflagellatea, Pelobiontida) Alexander O. Frolov 1, Andrew V. Goodkov 2, Ludmila V. Chystjakova 3 and Sergei O. Skarlato 2 1 Zoological Institute RAS, St. Petersburg, Russia 2 Institute of Cytology RAS, St. Petersburg, Russia 3 Biological Research Institute of St. Petersburg State University, Russia Summary The general morphology, ultrastructure, and development of a new pelobiont protist, Pelomyxa gruberi, have been described. The entire life cycle of this eukaryotic microbe involves an alteration of uni and multinucleate stages and is commonly completed within a year. Reproduction occurs by plasmotomy of multinucleate amoebae: they form division rosettes or divide unequally. Various surface parts of this slowlymoving organism characteristically form fingershaped hyaline protrusions. Besides, during the directed monopodial movement, a broad zone of hyaline cytoplasm with slender fingershaped hyaline protrusions is formed at the anterior part of the cell. In multinucleate stages up to 16 or even 32 nuclei of a vesicular type may be counted. Individuals with the highest numbers of nuclei were reported from the southernmost part of the investigated area: the NorthWest Russia. Each nucleus of all life cycle stages is surrounded with microtubules. The structure of the flagellar apparatus differs in individuals of different age. Small uninucleate forms have considerably fewer flagella per cell than do larger or multinucleate amoebae but these may have aflagellated basal bodies submerged into the cytoplasm. In young individuals, undulipodia, where available, emerge from a characteristic flagellar pocket or tunnel. The basal bodies and associated rootlet microtubular derivatives (one radial and one basal) are organized similarly at all life cycle stages.
    [Show full text]
  • Protistology Light-Microscopic Morphology and Ultrastructure Of
    Protistology 13 (1), 26–35 (2019) Protistology Light-microscopic morphology and ultrastructure of Polychaos annulatum (Penard, 1902) Smirnov et Goodkov, 1998 (Amoebozoa, Tubulinea, Euamo- ebida), re-isolated from the surroundings of St. Petersburg (Russia) Oksana Kamyshatskaya1,2, Yelisei Mesentsev1, Ludmila Chistyakova2 and Alexey Smirnov1 1 Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia 2 Core Facility Center “Culturing of microorganisms”, Research park of St. Petersburg State Univeristy, St. Petersburg State University, Botanicheskaya St., 17A, 198504, Peterhof, St. Petersburg, Russia | Submitted December 15, 2018 | Accepted January 21, 2019 | Summary We isolated the species Polychaos annulatum (Penard, 1902) Smirnov et Goodkov, 1998 from a freshwater habitat in the surrounding of Saint-Petersburg. The previous re-isolation of this species took place in 1998; at that time the studies of its light- microscopic morphology were limited with the phase contrast optics, and the electron- microscopic data were obtained using the traditional glutaraldehyde fixation, preceded with prefixation and followed by postfixation with osmium tetroxide. In the present paper, we provide modern DIC images of P. annulatum. Using the fixation protocol that includes a mixture of the glutaraldehyde and paraformaldehyde we were able to obtain better fixation quality for this species. We provide some novel details of its locomotive morphology, nuclear morphology, and ultrastructure. The present finding evidence that P. annulatum is a widely distributed species that could be isolated from a variety of freshwater habitats. Key words: amoebae, Polychaos, ultrastructure, Amoebozoa Introduction Amoeba proteus). These amoebae usually have a relatively large size, exceeding hundred of microns, The largest species of naked lobose amoebae they produce broad, thick pseudopodia with (gymnamoebae) – members of the family Amoe- smooth outlines (lobopodia).
    [Show full text]
  • The Evolution of Ogres: Cannibalistic Growth in Giant Phagotrophs
    bioRxiv preprint doi: https://doi.org/10.1101/262378; this version posted February 12, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Bloomfield, 2018-02-08 – preprint copy - bioRχiv The evolution of ogres: cannibalistic growth in giant phagotrophs Gareth Bloomfell MRC Laboratory of Molecular Biology, Cambrilge, UK [email protected] twitter.com/iliomorph Abstract Eukaryotes span a very large size range, with macroscopic species most often formel in multicellular lifecycle stages, but sometimes as very large single cells containing many nuclei. The Mycetozoa are a group of amoebae that form macroscopic fruiting structures. However the structures formel by the two major mycetozoan groups are not homologous to each other. Here, it is proposel that the large size of mycetozoans frst arose after selection for cannibalistic feeling by zygotes. In one group, Myxogastria, these zygotes became omnivorous plasmolia; in Dictyostelia the evolution of aggregative multicellularity enablel zygotes to attract anl consume surrounling conspecifc cells. The cannibalism occurring in these protists strongly resembles the transfer of nutrients into metazoan oocytes. If oogamy evolvel early in holozoans, it is possible that aggregative multicellularity centrel on oocytes coull have precelel anl given rise to the clonal multicellularity of crown metazoa. Keyworls: Mycetozoa; amoebae; sex; cannibalism; oogamy Introduction – the evolution of Mycetozoa independently in several diverse lineages, presumably reflecting strong selection for effective dispersal [9]. The dictyostelids (social amoebae or cellular slime moulds) and myxogastrids (also known as myxomycetes and true or The close relationship between dictyostelia and myxogastria acellular slime moulds) are protists that form macroscopic suggests that they shared a common ancestor that formed fruiting bodies (Fig.
    [Show full text]
  • (Amoebozoa, Discosea, Dactylopodida) — a New Freshwater Amoeba with Unusual Combination of Scales
    Protistology 11 (4), 238–247 (2017) Protistology Korotnevella novazelandica n. sp. (Amoebozoa, Discosea, Dactylopodida) — a new freshwater amoeba with unusual combination of scales Ilya A. Udalov1, Eckhard Völcker2 and Alexey Smirnov1 1 Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia 2 Penard Labs, Cape Town, South Africa | Submitted November 25, 2017 | Accepted December 6, 2017 | Summary A new freshwater species of naked lobose amoebae, Korotnevella novazelandica n. sp. (Amoebozoa, Discosea, Flabellinia, Dactylopodida), from New Zealand was studied and described. This species has sombrero-shaped as well as dish-shaped scales, a combination previously not known in Korotnevella. Phylogenetic analysis based on 18S rRNA gene placed it in a clade along with Korotnevella species possessing uniform sombrero-shaped scales: K. pelagolacustris, K. jeppesenii and K. fousta. At the level of light microscopy, K. novazelandica lacks clear distinctions from the above-mentioned species, but it could be easily distinguished from them in electron microscopy by the presence of dish-shaped scales. The presence of dish-shaped scales may be considered as a primitive character for the K. pelagolacustris + K. jeppesenii + K. fousta + K. novazelandica clade, which were secondarily lost in the most of species in this clade. The sombrero-shaped scales could have evolved from basket scales or developed de novo after the loss of basket scales. Key words: 18S rRNA gene, Korotnevella, molecular phylogeny, scales, systematics, ultrastructure Introduction considered to be species-specific (Pennick and Goodfellow, 1975; Page, 1981; Smirnov, 1999; The genus Korotnevella encompasses flattened O’Kelly et al., 2001; Udalov, 2015, 2016; Udalov amoebae of dactylopodial morphotype (Smirnov et al., 2016; Zlatogursky et al., 2016; Van Wichelen and Goodkov, 1999; Smirnov and Brown, 2004), et al., 2016).
    [Show full text]
  • Comprehensive Phylogenetic Reconstruction of Amoebozoa Based on Concatenated Analyses of SSU-Rdna and Actin Genes
    Smith ScholarWorks Biological Sciences: Faculty Publications Biological Sciences 8-2-2011 Comprehensive Phylogenetic Reconstruction of Amoebozoa Based on Concatenated Analyses of SSU-rDNA and Actin Genes Daniel J.G. Lahr University of Massachusetts Amherst Jessica Grant Smith College Truc Nguyen Smith College Jian Hua Lin Smith College Laura A. Katz Smith College, [email protected] Follow this and additional works at: https://scholarworks.smith.edu/bio_facpubs Part of the Biology Commons Recommended Citation Lahr, Daniel J.G.; Grant, Jessica; Nguyen, Truc; Lin, Jian Hua; and Katz, Laura A., "Comprehensive Phylogenetic Reconstruction of Amoebozoa Based on Concatenated Analyses of SSU-rDNA and Actin Genes" (2011). Biological Sciences: Faculty Publications, Smith College, Northampton, MA. https://scholarworks.smith.edu/bio_facpubs/121 This Article has been accepted for inclusion in Biological Sciences: Faculty Publications by an authorized administrator of Smith ScholarWorks. For more information, please contact [email protected] Comprehensive Phylogenetic Reconstruction of Amoebozoa Based on Concatenated Analyses of SSU- rDNA and Actin Genes Daniel J. G. Lahr1,2, Jessica Grant2, Truc Nguyen2, Jian Hua Lin2, Laura A. Katz1,2* 1 Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, United States of America, 2 Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America Abstract Evolutionary relationships within Amoebozoa have been the subject
    [Show full text]
  • Marine Biological Laboratory) Data Are All from EST Analyses
    TABLE S1. Data characterized for this study. rDNA 3 - - Culture 3 - etK sp70cyt rc5 f1a f2 ps22a ps23a Lineage Taxon accession # Lab sec61 SSU 14 40S Actin Atub Btub E E G H Hsp90 M R R T SUM Cercomonadida Heteromita globosa 50780 Katz 1 1 Cercomonadida Bodomorpha minima 50339 Katz 1 1 Euglyphida Capsellina sp. 50039 Katz 1 1 1 1 4 Gymnophrea Gymnophrys sp. 50923 Katz 1 1 2 Cercomonadida Massisteria marina 50266 Katz 1 1 1 1 4 Foraminifera Ammonia sp. T7 Katz 1 1 2 Foraminifera Ovammina opaca Katz 1 1 1 1 4 Gromia Gromia sp. Antarctica Katz 1 1 Proleptomonas Proleptomonas faecicola 50735 Katz 1 1 1 1 4 Theratromyxa Theratromyxa weberi 50200 Katz 1 1 Ministeria Ministeria vibrans 50519 Katz 1 1 Fornicata Trepomonas agilis 50286 Katz 1 1 Soginia “Soginia anisocystis” 50646 Katz 1 1 1 1 1 5 Stephanopogon Stephanopogon apogon 50096 Katz 1 1 Carolina Tubulinea Arcella hemisphaerica 13-1310 Katz 1 1 2 Cercomonadida Heteromita sp. PRA-74 MBL 1 1 1 1 1 1 1 7 Rhizaria Corallomyxa tenera 50975 MBL 1 1 1 3 Euglenozoa Diplonema papillatum 50162 MBL 1 1 1 1 1 1 1 1 8 Euglenozoa Bodo saltans CCAP1907 MBL 1 1 1 1 1 5 Alveolates Chilodonella uncinata 50194 MBL 1 1 1 1 4 Amoebozoa Arachnula sp. 50593 MBL 1 1 2 Katz lab work based on genomic PCRs and MBL (Marine Biological Laboratory) data are all from EST analyses. Culture accession number is ATTC unless noted. GenBank accession numbers for new sequences (including paralogs) are GQ377645-GQ377715 and HM244866-HM244878.
    [Show full text]