DOCSLIB.ORG

Protistology Structure and Development of Pelomyxa Gruberi

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read 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. There is a thinwalled cylinder in the flagellar transition zone, and an electrondense column above that zone. In the separate nonmotile undulipodia the arrangement of axoneme microtubules deviates from the typical 9+2 eukaryotic pattern. In the cytoplasm of P. gruberi two types of rodshaped endocytobionts are present: (1) large bacteria with a pronounced longitudinal cleft, and (2) smaller methanogenlike bacteria. Key words: systematics, life cycle, Pelobiontida, Pelomyxa gruberi sp. n., ultrastructure, cytoskeleton © 2006 by Russia, Protistology 228 · Alexander O. Frolov et al. Introduction almost stagnant permanent water bodies. The samples were taken near the bank, at a depth of 570 cm. The systematics of the genus Pelomyxa Greeff 1874 Attempts to establish Pelomyxa cultures failed, but the was influenced for a long time by two opposite views collected amoebae survived for up to 14 months in with regard to both qualitative and quantitative samples put in hermetically sealed 300 ml vessels and composition of this taxon. On the one hand, nearly 20 kept at about 10°С. Alive individuals were investigated species had been described within a century resulting in closed microaquaria, with a volume of 2.5 ml3, from numerous observations of Pelomyxalike amoebae connected via a running system with a 0.5 l vessel filled (Gruber, 1884; Penard, 1902; Goodkov et al., 2004). with water and silt from their natural habitat. The On the other hand, the validity of most of these species system was maintained at 10°С and transferred to room was often doubted (Page, 1981, 1988; Whatley and temperature only for observation. ChapmanAndresen, 1990). Results of studies into the Leika microscope equipped with visualisation life cycle of P. palustris (the type species) seemed to systems on the basis of Panasonic 650 CCTV + Canon resolve the question in favour of monotypy of the genus EOS350D and PC P4 was used. All measurements were Pelomyxa (ChapmanAndresen, 1978, 1982). It was made on live individuals, with the help of the image postulated that all Pelomyxa species ever described were analysis system IT v.2.2 (UTHSCSA). merely particular stages of the complex life cycle of the For electron microscopy the amoebae were fixed sole polymorphic species P. palustris (Whatley and with a cocktail of 5% glutaraldehyde and 0.5% OsO4 ChapmanAndresen, 1990). Since then no other (1:1) on 0.1 M cacodylate buffer. Fixation was detailed studies of multinucleate pelobionts followed, performed on melting ice in the dark for 4 h, followed and until recently the above concept remained by the fixative replacement in 15 min. Then fixed dominating in special protistological literature (Whatley amoebae were washed in 0.1 M cacodylate buffer (15 and ChapmanAndresen, 1990; Page and Siemensma, min) and postfixed with 2% OsO4 on 0.1 M cacodylate 1991; Brugerolle, 1991; Brugerolle and Patterson, 2002; buffer in total darkness on melting ice (1 h). Goodkov et al., 2004). After a transition through a graded ascending The situation has dramatically changed when alcohol series, the material was embedded in Epon Frolov et al. (2005a, 2005b) reported results of their Araldite mixture. To facilitate the preparation of ultrastructural studies of such "life cycle stages" of P. ultrathin sections, the objects embedded in the resin palustris as P. binucleata (Gruber 1884) ("division were treated with 10% solution of hydrofluoric acid product of large, grey type of P. palustris" sensu Whatley (HF). Ultrathin sections were cut with a Reichert and ChapmanAndresen, 1990) and P. prima (Gruber ultratome and viewed in the Tesla BS300 electron 1884) ("young growth phase of P. palustris" sensu microscope. Whatley and ChapmanAndresen, 1990). The obtained morphological characters allowed reliable differen Results tiation between P. binucleata, P. prima, and the type species P. palustris. The most considerable differences Pelomyxa gruberi sp. n. (Figs 110). involved basal parts of flagella, nuclear organization and Diagnosis: Rounded (feeding stages) or elongated cell surface of examined species of Pelomyxa. The cylindrical (locomotive stages) amoeboid organisms. A provided evidence (Frolov et al., 2004, 2005a, 2005b) welldeveloped broad zone of hyaline cytoplasm with resumed an interest to the previous question about the slender fingerlike hyaline protrusions formed at the true biodiversity of multinucleate pelobionts. anterior body end during locomotion. Cell diameter In the present paper, a new species of pelobionts, varies from 80 !m (young uninucleate individuals) to Pelomyxa gruberi, is described. The species name is 350 !m (multinucleate locomotive forms). In the life given in honour of Professor August Gruber (University cycle, uninucleate developmental stages alternate with of Freiburg, Germany), whose detailed descriptions of multinucleate ones. Reproduction occurs by plasma Pelomyxalike amoebae (Gruber, 1884) anticipated tomy of multinucleate amoebae: they form division modern studies of pelomyxoid diversity. rosettes or divide unequally. The cytoplasm clearly differentiated into ectoplasm and endoplasm. Vesicular Material and Methods nuclei (132 per cell) with a single central nucleolus. Nuclear envelope surrounded with microtubules in all Pelomyxa amoebae were collected in freshwater life cycle stages. Flagella are numerous, nonmotile; basins in the NorthWest Russia (Sosnovo Village, the axoneme with a nonstandard microtubular pattern. Leningrad region, 60° 30' N, 30° 30' E and Lyady Long basal bodies deeply submerged into the cytoplasm Village, the Pskov Region, about 58° 35' N, 28° 55' E). and associated with microtubular derivatives of two The amoebae were found in silt samples from fully or types. First type derivatives (over 150 radial micro Protistology · 229 tubules) start from the lateral basal body surface. Second After numerous observations within the latest three type derivatives (about 60 microtubules) are represented years, we established in the life cycle of P. gruberi the by one or two compact bundles originating from the alternation of uninucleate and multinucleate stages bottom of the basal body. A thinwalled cylinder is (Fig. 1). Prevalence of uninucleate individuals and mass present in the transition zone, an electrondense appearance of multinucleate stages in P. gruberi column is located above it. In the cytoplasm two types micropopulations occurred approximately once a year. of rodshaped endocytobionts are present: (1) large Interestingly, this cyclic recurrence was not season bacteria with a pronounced longitudinal cleft, and (2) related. Indeed, five micropopulations of P. gruberi were smaller methanogenlike bacteria. observed weekly in the Osinovskoye Lake from October Amoebae feed on small detritus particles, mostly to December, 2004. The five examined habitats were of vegetative origin. No glycogen bodies are formed in small silted anthropogenic bays on the west shore of the any life cycle stages. Cytoplasm colour varies from light lake. The bays, located 3050 m apart, had similar depth beige to dark brown. and bottom relief, in addition to identical shore Type locality: Sosnovo Village, the Leningrad landscapes. Table 1 summarises data on the proportion Region, 60° 30' N, 30° 30' E, NorthWest Russia. of uninucleate and multinucleate forms in these Type material: Holotype, slide N 934; Paratypes, micropopulations. Multinucleate amoebae were slides N 935 and N 936; deposited in the Type Slide registered only in one of the five above habitats (bay 4). Collection, Laboratory of Unicellular Organisms, Subsequent observations showed that in bays 13 and 5 Institute of Cytology RAS, St. Petersburg, Russia. the multinucleate
Load more

Recommended publications
  • 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]
  • The Shigella Type III Secretion System: an Overview from Top to Bottom
    microorganisms Review The Shigella Type III Secretion System: An Overview from Top to Bottom Meenakumari Muthuramalingam, Sean K. Whittier, Wendy L. Picking and William D. Picking * Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66049, USA; [email protected] (M.M.); [email protected] (S.K.W.); [email protected] (W.L.P.) * Correspondence: [email protected]; Tel.: +1-785-864-5974 Abstract: Shigella comprises four species of human-restricted pathogens causing bacillary dysen- tery. While Shigella possesses multiple genetic loci contributing to virulence, a type III secretion system (T3SS) is its primary virulence factor. The Shigella T3SS nanomachine consists of four major assemblies: the cytoplasmic sorting platform; the envelope-spanning core/basal body; an exposed needle; and a needle-associated tip complex with associated translocon that is inserted into host cell membranes. The initial subversion of host cell activities is carried out by the effector functions of the invasion plasmid antigen (Ipa) translocator proteins, with the cell ultimately being controlled by dedicated effector proteins that are injected into the host cytoplasm though the translocon. Much of the information now available on the T3SS injectisome has been accumulated through collective studies on the T3SS from three systems, those of Shigella flexneri, Salmonella typhimurium and Yersinia enterocolitica/Yersinia pestis. In this review, we will touch upon the important features of the T3SS injectisome that have come to light because of research in the Shigella and closely related systems. We will also briefly highlight some of the strategies being considered to target the Shigella T3SS for Citation: Muthuramalingam, M.; disease prevention.
    [Show full text]
  • The Rac1 Regulator ELMO Controls Basal Body Migration and Docking
    © 2015. Published by The Company of Biologists Ltd | Development (2015) 142, 1553 doi:10.1242/dev.124214 CORRECTION The Rac1 regulator ELMO controls basal body migration and docking in multiciliated cells through interaction with Ezrin Daniel Epting, Krasimir Slanchev, Christopher Boehlke, Sylvia Hoff, Niki T. Loges, Takayuki Yasunaga, Lara Indorf, Sigrun Nestel, Soeren S. Lienkamp, Heymut Omran, E. Wolfgang Kuehn, Olaf Ronneberger, Gerd Walz and Albrecht Kramer-Zucker There was an error published in Development 142, 174-184. In the supplementary material (mRNA and morpholino injection) the morpholino SB-MO dock1 was incorrectly listed as: 5′-ACACTCTAGTGAGTATAGTGTGCAT-3′. The correct sequence is: 5′-ACCATCCTGAGAAGAGCAAGAAATA-3′ (corresponding to MO4-dock1 in ZFIN). The authors apologise to readers for this mistake. DEVELOPMENT 1553 © 2015. Published by The Company of Biologists Ltd | Development (2015) 142, 174-184 doi:10.1242/dev.112250 RESEARCH ARTICLE The Rac1 regulator ELMO controls basal body migration and docking in multiciliated cells through interaction with Ezrin Daniel Epting1, Krasimir Slanchev1, Christopher Boehlke1, Sylvia Hoff1, Niki T. Loges2, Takayuki Yasunaga1, Lara Indorf1, Sigrun Nestel3, Soeren S. Lienkamp1,4, Heymut Omran2, E. Wolfgang Kuehn1,4, Olaf Ronneberger4,5, Gerd Walz1,4 and Albrecht Kramer-Zucker1,* ABSTRACT assembly of this network involves actin regulators such as RhoA and Cilia are microtubule-based organelles that are present on most cells the phosphate loop ATPase Nubp1 (Pan et al., 2007; Ioannou et al., and are required for normal tissue development and function. Defective 2013). The docking of the basal bodies modifies the formation of the cilia cause complex syndromes with multiple organ manifestations apical actin network, and defects that impair docking are often termed ciliopathies.
    [Show full text]
  • Nascent Chain-Monitored Remodeling of the Sec Machinery for Salinity
    Correction MICROBIOLOGY Correction for “Nascent chain-monitored remodeling of the Sec USA (112:E5513–E5522; first published September 21, 2015; 10.1073/ machinery for salinity adaptation of marine bacteria,” by Eiji pnas.1513001112). Ishii, Shinobu Chiba, Narimasa Hashimoto, Seiji Kojima, Michio The authors note that Fig. 6 appeared incorrectly. The cor- Homma, Koreaki Ito, Yoshinori Akiyama, and Hiroyuki Mori, rected figure and its legend appear below. which appeared in issue 40, October 6, 2015, of Proc Natl Acad Sci A Fig. 6. Regulatory importance of the vemP-secD2-secF2 operon arrangement. (A) Predicted secondary structure of mRNA at the vemP-secD2VA intergenic re- gion. The RNA sequence from the fifth last codon of vemP to the third codon of secD2VA are shown with the secondary structure predicted by CentroidHomfold. The putative SD sequence and the start codon of secD2VA are indicated by box and underline, respectively. The P site and the A site of the VemP-stalled ribo- some (Fig. 4C) are shown schematically. To separate the VemP arrest point and CORRECTION the secondary structure-forming region, we inserted one or two copies of the 18 B C nucleotides encoding the last five amino acid residues of VemP followed by the termination codon, shown at the bottom. (B) Separation of the arrest point and the stem-loop-forming region impairs the regulation. E. coli cells carrying in- dicated vemP-secDF2VA plasmids (with or without the insertion mutations shown in A) were induced with IPTG for 15 min at 37 °C and treated with (+) or without (−)3mMNaN3 for 5 min. Cells were then pulse-labeled for 1 min.
    [Show full text]
  • The Role of the Flagellar Transition Region: Inferences from the Analysis of a Chlamydomonas Mutant with Defective Transition Region Structures
    The role of the flagellar transition region: inferences from the analysis of a Chlamydomonas mutant with defective transition region structures JONATHAN W. JARVIK and JOSEPH P. SUHAN Department of Biological Sciences, Carnegie Mellon Uniuersity,4400 Fifth Auenue, Pittsburgh, PA 15213, USA Summary Thin-section electron microscopy of the Chlamy- autotomy the process by which doublet micro- domonas reinhardtii mutant vfl-2 revealed striking tubules are severed and flagella are released from defects in the transition region between basal body the cell. It has been claimed that autotomy is caused and flagelhrm. In place of the highly organized by contraction of the centrin-containing stellate transition cylinders and stellate fibers characteristic fibers, resulting in the mechanical severing of the of wild type, variable quantities of poorly organized doublet microtubules and a concomitant reduction of electron-dense material were present. In many cases the diameter of the axoneme adjacent to the abscis- the transition region was penetrated by central pair sion point. Our observations do not support this microtubules that passed from the axoneme into the claim in that vfl-2 cells, which lack organized stellate basal body. On the basis of these observations we fibers, display effective autotomy unaccompanied by propose that an important function of the structures detectable narrowing of the axoneme. present in the normal transition region is to physi- cally exclude the central pair microtubules from the basal body. Key words: autotomy, flagella, Chlamydomonas, transition The transition region is the site of flagellar region, microtubules, centrin. lntroduction membrane from the plasma membrane (Musgrave et al. 1986; Kaneshiro, 1989), partitioning the flagellar interior The specialtzed region between the eucaryotic cilium or from the cytosol (Besharse and Horst, 1990), and auto- flagellum and its basal body is known as the transition tomy, or flagellar shedding (Bluh, L97L).
    [Show full text]
  • TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes
    RESEARCH ARTICLE TAC102 Is a Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes Roman Trikin1,2☯, Nicholas Doiron1☯, Anneliese Hoffmann1,2, Beat Haenni3, Martin Jakob1, Achim Schnaufer4, Bernd Schimanski1, Benoît Zuber3, Torsten Ochsenreiter1* 1 Institute of Cell Biology, University of Bern, Bern, Switzerland, 2 Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland, 3 Institute of Anatomy, University of Bern, Bern, Switzerland, 4 Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, Scotland, United Kingdom a11111 ☯ These authors contributed equally to this work. * [email protected] Abstract Trypanosomes show an intriguing organization of their mitochondrial DNA into a catenated OPEN ACCESS network, the kinetoplast DNA (kDNA). While more than 30 proteins involved in kDNA repli- Citation: Trikin R, Doiron N, Hoffmann A, Haenni B, cation have been described, only few components of kDNA segregation machinery are cur- Jakob M, Schnaufer A, et al. (2016) TAC102 Is a rently known. Electron microscopy studies identified a high-order structure, the tripartite Novel Component of the Mitochondrial Genome Segregation Machinery in Trypanosomes. PLoS attachment complex (TAC), linking the basal body of the flagellum via the mitochondrial Pathog 12(5): e1005586. doi:10.1371/journal. membranes to the kDNA. Here we describe TAC102, a novel core component of the TAC, ppat.1005586 which is essential for proper kDNA segregation during cell division. Loss of TAC102 leads Editor: Kent L. Hill, University of California, Los to mitochondrial genome missegregation but has no impact on proper organelle biogenesis Angeles, UNITED STATES and segregation. The protein is present throughout the cell cycle and is assembled into the Received: November 19, 2015 newly developing TAC only after the pro-basal body has matured indicating a hierarchy in de Accepted: March 30, 2016 the assembly process.
    [Show full text]
  • Outer Membrane Protein Functions As Integrator of Protein Import And
    Outer membrane protein functions as integrator of PNAS PLUS protein import and DNA inheritance in mitochondria Sandro Käsera, Silke Oeljeklausb,Jirí Týcˇc, Sue Vaughanc, Bettina Warscheidb,d,1, and André Schneidera,1 aDepartment of Chemistry and Biochemistry, University of Bern, Bern CH-3012, Switzerland; bDepartment of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg 79104, Germany; cDepartment of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom; and dCentre for Biological Signalling Studies (BIOSS), University of Freiburg, Freiburg 79104, Germany Edited by Paul T. Englund, Johns Hopkins University, Baltimore, MD, and approved June 14, 2016 (received for review April 5, 2016) Trypanosomatids are one of the earliest diverging eukaryotes that respectively, although ATOM40 also shows similarity to a bacte- have fully functional mitochondria. pATOM36 is a trypanosomatid- rial β-barrel protein. The four remaining translocase subunits specific essential mitochondrial outer membrane protein that has (ATOM11, ATOM12, ATOM46, and ATOM69) do not show been implicated in protein import. Changes in the mitochondrial pro- similarity to TOM complex subunits of yeast or any other organ- teome induced by ablation of pATOM36 and in vitro assays show that ism outside the Kinetoplastids. Two of them, ATOM46 and pATOM36 is required for the assembly of the archaic translocase of ATOM69, have large cytosolic domains and function as protein the outer membrane (ATOM), the functional analog of the TOM com- import receptors. Their function is analogous to Tom20 and plex in other organisms. Reciprocal pull-down experiments and im- Tom70 of yeast, even though they do not show sequence similarity munofluorescence analyses demonstrate that a fraction of pATOM36 with any of these proteins and thus arose by convergent evolution interacts and colocalizes with TAC65, a previously uncharacterized (12).
    [Show full text]
  • Isolation of the Buchnera Aphidicola Flagellum Basal Body from the Buchnera Membrane
    bioRxiv preprint doi: https://doi.org/10.1101/2021.01.07.425737; this version posted January 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Isolation of the Buchnera aphidicola flagellum basal body from the Buchnera membrane Matthew J. Schepers1, James N. Yelland1, Nancy A. Moran2*, David W. Taylor1,3-5* 1Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX, 78712 2Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712 3Departmnet of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712 4Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, 78712 5LIVESTRONG Cancer Institute, Dell Medical School, Austin, TX, 78712 *Correspondence to: [email protected] (D.W.T.); [email protected] (N.A.M.) bioRxiv preprint doi: https://doi.org/10.1101/2021.01.07.425737; this version posted January 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Abstract Buchnera aphidicola is an intracellular bacterial symbiont of aphids and maintains a small genome of only 600 kbps. Buchnera is thought to maintain only genes relevant to the symbiosis with its aphid host. Curiously, the Buchnera genome contains gene clusters coding for flagellum basal body structural proteins and for flagellum type III export machinery. These structures have been shown to be highly expressed and present in large numbers on Buchnera cells.
    [Show full text]
  • The Formation of Basal Bodies (Centrioles)
    THE FORMATION OF BASAL BODIES (CENTRIOLES) IN THE RHESUS MONKEY OVIDUCT RICHARD G. W. ANDERSON and ROBERT M. BRENNER From the Oregon Regional Primate Research Center, Beaverton, Oregon 97005 ABSTRACT Basal body replication during estrogen-drlven ciliogenesis in the rhesus monkey (Macaca mulatta) oviduct has been studied by stereomicroscopy, rotation photography, and serial section analysis. Two pathways for basal body production are described: acentriolar basal body formation (major pathway) where procentrioles are generated from a spherical aggregate of fibers; and centriolar basal body formation, where procentrioles are generated by the diplosomal centrioles. In both pathways, the first step in procentriole formation is the arrangement of a fibrous granule precursor into an annulus. A cartwheel structure, present within the lumen of the annulus, is composed of a central cylinder with a core, spoke components, and anchor filaments. Tubule formation consists of an initiation and a growth phase. The A tubule of each triplet set first forms within the wall material of the annulus in juxtaposition to a spoke of the cartwheel. After all nine A tubules are initiated, B and C tubules begin to form. The initiation of all three tubules occurs sequentially around the procentriole. Simultaneous with tubule initiation is a nonsequential growth of each tubule. The tubules lengthen and the procentriole is complete when it is about 200 m/z long. The procentriole increases in length and diameter during its maturation into a basal body. The addition of a basal foot, nine alar sheets, and a rootlet completes the mat- uration process. Fibrous granules are also closely associated with the formation of these basal body accessory structures.
    [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]
  • Significance for Endosymbiosis Theory
    7reb. Soc. C'a'. Biol., Vol. 41 (1990) 5-16 KINETOSOME-CENTRIOLAR DNA: SIGNIFICANCE FOR ENDOSYMBIOSIS THEORY LYNN MARGULIS' and MARK MCMENAMIN2 'Department of Botany, University of Massachussetts. Amherst, USA. 'Department of Geology and Geography, Mt. Holyoke College. South Hadley, USA. SUMMARY The "extreme version" of the serial endosymbiosis theory (SET) postulates three types of integration of bacterial symbionts into what became the nucleocytoplasm of nucleated cells. The first, a symbiosis between motile bacteria and less motile archaeobacterial hosts is thought to have resulted in the origin of nucleocytoplasm capable of both internal movement and motility by undulipodia. That is, microtubule-based motility systems of eukaryotic cells (kinetosome- centrioles, undulipodia including cilia, mitotic spindles, etc.) are hypothesized to have evolved from symbiotic associations of spirochetes with Therinoplasma-like archaeobacteria (protonu- cleocytoplasm). The second, a symbiosis between aerobically respiring bacteria and the nucleocy- toplasm, resulted in mitochondria of aerobic eukaryotes. The third association led to photosynthe- tic plastids from undigested cyanobacteria. Whereas the symbiotic origins of plastids and mitochondria are firmly established, the recent discovery by David LUCK and his colleagues of centriole-kinetosome DNA greatly enhances the likelihood that the last postulate concerning motility is valid. We can thus anticipate a rapid, definitive test of the "extreme version" of the SET. Unknown to most Western scientists, the hypothesis of the origin of eukaryotic cell motility from symbiotic bacteria has a Russian antecedent: the concept of symbiogenesis or origin of evolutionary novelty via hereditary symbiosis was well developed by Russian biologists late in the last century and early in this one.
    [Show full text]