Essential Function of the Alveolin Network in the Subpellicular
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Basal Body Structure and Composition in the Apicomplexans Toxoplasma and Plasmodium Maria E
Francia et al. Cilia (2016) 5:3 DOI 10.1186/s13630-016-0025-5 Cilia REVIEW Open Access Basal body structure and composition in the apicomplexans Toxoplasma and Plasmodium Maria E. Francia1* , Jean‑Francois Dubremetz2 and Naomi S. Morrissette3 Abstract The phylum Apicomplexa encompasses numerous important human and animal disease-causing parasites, includ‑ ing the Plasmodium species, and Toxoplasma gondii, causative agents of malaria and toxoplasmosis, respectively. Apicomplexans proliferate by asexual replication and can also undergo sexual recombination. Most life cycle stages of the parasite lack flagella; these structures only appear on male gametes. Although male gametes (microgametes) assemble a typical 9 2 axoneme, the structure of the templating basal body is poorly defined. Moreover, the rela‑ tionship between asexual+ stage centrioles and microgamete basal bodies remains unclear. While asexual stages of Plasmodium lack defined centriole structures, the asexual stages of Toxoplasma and closely related coccidian api‑ complexans contain centrioles that consist of nine singlet microtubules and a central tubule. There are relatively few ultra-structural images of Toxoplasma microgametes, which only develop in cat intestinal epithelium. Only a subset of these include sections through the basal body: to date, none have unambiguously captured organization of the basal body structure. Moreover, it is unclear whether this basal body is derived from pre-existing asexual stage centrioles or is synthesized de novo. Basal bodies in Plasmodium microgametes are thought to be synthesized de novo, and their assembly remains ill-defined. Apicomplexan genomes harbor genes encoding δ- and ε-tubulin homologs, potentially enabling these parasites to assemble a typical triplet basal body structure. -
Ultrastructural Studies in Fetal I-Cell Disease
Pediat. Res. 10: 669-676 (1976) Amniocentesis fetal I-cell disease cytoplasmic inclusions fetus Ultrastructural Studies in Fetal I-cell Disease KAZUHIRO ABE, ICHIRO MATSUDA, SHINICHIRO ARASHIMA(20' TAKASHI MITSUYAMA, YOGO OKA, AND MUTSUO ISHIKAWA Departments of Anatomy, Pediatrics, and Obstetrics and Gynecology, Hokkaido University School of Medicine, Sapporo, Japan Extract I-cells from the present fetus were described in separate papers (9, 1 1 ). The skin, brain, lung, liver, and kidney from a 20-week-old fetus who was diagnosed as having fetal I-cell disease by amniocentesis at MATERIALS AND METHODS 14 weeks of gestation were examined by light and electron microscopy. In addition, cultured fibroblasts from the skin were also A pregnancy of a 21-year-old mother from a family at risk for observed microscopically. Cytoplasmic inclusions with dense poly - I-cell disease was monitored and the diagnosis of the disease was morphic contents appeared commonly in the capillary endothelial made by biochemical examination of the amniotic fluid and cells cells in the skin, lung, glomerulus of the kidney, and the epithelial obtained at 14 weeks of gestation (9). The pregnancy was cells of the proximal tubules of the kidney, and sometimes in the interrupted by therapeutic abortion at 20 weeks of gestation. The hepatocytes of the liver and the nerve and glial cells of the brain. aborted fetus was male, 160 g in weight. and revealed macroscopi- Erythropoietic cells in the liver and circulating erythrocytes con- cally normal development corresponding to the fetal age. tained dense inclusions varying in developmental stages. Fibroblasts Immediately after the abortion, tissue fragments of the abdomi- of the skin had several clear vacuoles, and cultured fibroblasts were nal skin, brain, lung, liver, and kidney from the fetus were filled with dense inclusions. -
Swimming with Protists: Perception, Motility and Flagellum Assembly
REVIEWS Swimming with protists: perception, motility and flagellum assembly Michael L. Ginger*, Neil Portman‡ and Paul G. McKean* Abstract | In unicellular and multicellular eukaryotes, fast cell motility and rapid movement of material over cell surfaces are often mediated by ciliary or flagellar beating. The conserved defining structure in most motile cilia and flagella is the ‘9+2’ microtubule axoneme. Our general understanding of flagellum assembly and the regulation of flagellar motility has been led by results from seminal studies of flagellate protozoa and algae. Here we review recent work relating to various aspects of protist physiology and cell biology. In particular, we discuss energy metabolism in eukaryotic flagella, modifications to the canonical assembly pathway and flagellum function in parasite virulence. Protists The canonical ‘9+2’ microtubule axoneme is the prin- of inherited pathologies (or ciliopathies), including Eukaryotes that cannot be cipal feature of many motile cilia and flagella and is infertility, chronic respiratory disease, polycystic kid- classified as animals, fungi or one of the most iconic structures in cell biology. The ney disease and syndromes that include Bardet–Biedl, plants. The kingdom Protista origin of the eukaryotic flagellum and cilium is ancient Alstrom and Meckel syndrome6–12. Even illnesses such includes protozoa and algae. and predates the radiation, over 800 million years ago, as cancer, diabetes and obesity have been linked to cili- 1 6 Ciliates of the lineages that gave rise to extant eukaryotes . ary defects . The biological basis for some ciliopathies A ubiquitous group of protists, Therefore the absence of cilia and flagella from yeast, is undoubtedly defective sensing (an essential function members of which can be many fungi, red algae and higher plants are all examples provided by cilia), rather than defects in the assembly found in many wet of secondary loss. -
Ciliary Chemosensitivity Is Enhanced by Cilium Geometry and Motility
bioRxiv preprint doi: https://doi.org/10.1101/2021.01.13.425992; this version posted January 14, 2021. 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 4.0 International license. Ciliary chemosensitivity is enhanced by cilium geometry and motility David Hickey,1 Andrej Vilfan,1, 2, ∗ and Ramin Golestanian1, 3 1Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 G¨ottingen,Germany 2JoˇzefStefan Institute, 1000 Ljubljana, Slovenia 3Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3PU, United Kingdom (Dated: January 13, 2021) Cilia are hairlike organelles involved in both sensory functions and motility. We discuss the question of whether the location of chemical receptors on cilia provides an advantage in terms of sensitivity. Using a simple advection-diffusion model, we compute the capture rates of diffusive molecules on a cilium. Because of its geometry, a non-motile cilium in a quiescent fluid has a capture rate equivalent to a circular absorbing region with ∼ 4× its surface area. When the cilium is exposed to an external shear flow, the equivalent surface area increases to ∼ 10×. Alternatively, if the cilium beats in a non-reciprocal way, its capture rate increases with the beating frequency to the power of 1=3. Altogether, our results show that the protruding geometry of a cilium could be one of the reasons why so many receptors are located on cilia. They also point to the advantage of combining motility with chemical reception. -
Unfolding the Secrets of Coral–Algal Symbiosis
The ISME Journal (2015) 9, 844–856 & 2015 International Society for Microbial Ecology All rights reserved 1751-7362/15 www.nature.com/ismej ORIGINAL ARTICLE Unfolding the secrets of coral–algal symbiosis Nedeljka Rosic1, Edmund Yew Siang Ling2, Chon-Kit Kenneth Chan3, Hong Ching Lee4, Paulina Kaniewska1,5,DavidEdwards3,6,7,SophieDove1,8 and Ove Hoegh-Guldberg1,8,9 1School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia; 2University of Queensland Centre for Clinical Research, The University of Queensland, Herston, Queensland, Australia; 3School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Queensland, Australia; 4The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, Australia; 5Australian Institute of Marine Science, Townsville, Queensland, Australia; 6School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia; 7Australian Centre for Plant Functional Genomics, The University of Queensland, St Lucia, Queensland, Australia; 8ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Queensland, Australia and 9Global Change Institute and ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Queensland, Australia Dinoflagellates from the genus Symbiodinium form a mutualistic symbiotic relationship with reef- building corals. Here we applied massively parallel Illumina sequencing to assess genetic similarity and diversity among four phylogenetically diverse dinoflagellate clades (A, B, C and D) that are commonly associated with corals. We obtained more than 30 000 predicted genes for each Symbiodinium clade, with a majority of the aligned transcripts corresponding to sequence data sets of symbiotic dinoflagellates and o2% of sequences having bacterial or other foreign origin. -
Identification of a Novel Fused Gene Family Implicates Convergent
Chen et al. BMC Genomics (2018) 19:306 https://doi.org/10.1186/s12864-018-4685-y RESEARCH ARTICLE Open Access Identification of a novel fused gene family implicates convergent evolution in eukaryotic calcium signaling Fei Chen1,2,3, Liangsheng Zhang1, Zhenguo Lin4 and Zong-Ming Max Cheng2,3* Abstract Background: Both calcium signals and protein phosphorylation responses are universal signals in eukaryotic cell signaling. Currently three pathways have been characterized in different eukaryotes converting the Ca2+ signals to the protein phosphorylation responses. All these pathways have based mostly on studies in plants and animals. Results: Based on the exploration of genomes and transcriptomes from all the six eukaryotic supergroups, we report here in Metakinetoplastina protists a novel gene family. This family, with a proposed name SCAMK,comprisesSnRK3 fused calmodulin-like III kinase genes and was likely evolved through the insertion of a calmodulin-like3 gene into an SnRK3 gene by unequal crossover of homologous chromosomes in meiosis cell. Its origin dated back to the time intersection at least 450 million-year-ago when Excavata parasites, Vertebrata hosts, and Insecta vectors evolved. We also analyzed SCAMK’s unique expression pattern and structure, and proposed it as one of the leading calcium signal conversion pathways in Excavata parasite. These characters made SCAMK gene as a potential drug target for treating human African trypanosomiasis. Conclusions: This report identified a novel gene fusion and dated its precise fusion time -
The Planktonic Protist Interactome: Where Do We Stand After a Century of Research?
bioRxiv preprint doi: https://doi.org/10.1101/587352; this version posted May 2, 2019. 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. Bjorbækmo et al., 23.03.2019 – preprint copy - BioRxiv The planktonic protist interactome: where do we stand after a century of research? Marit F. Markussen Bjorbækmo1*, Andreas Evenstad1* and Line Lieblein Røsæg1*, Anders K. Krabberød1**, and Ramiro Logares2,1** 1 University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology (Evogene), Blindernv. 31, N- 0316 Oslo, Norway 2 Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, ES-08003, Barcelona, Catalonia, Spain * The three authors contributed equally ** Corresponding authors: Ramiro Logares: Institute of Marine Sciences (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain. Phone: 34-93-2309500; Fax: 34-93-2309555. [email protected] Anders K. Krabberød: University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology (Evogene), Blindernv. 31, N-0316 Oslo, Norway. Phone +47 22845986, Fax: +47 22854726. [email protected] Abstract Microbial interactions are crucial for Earth ecosystem function, yet our knowledge about them is limited and has so far mainly existed as scattered records. Here, we have surveyed the literature involving planktonic protist interactions and gathered the information in a manually curated Protist Interaction DAtabase (PIDA). In total, we have registered ~2,500 ecological interactions from ~500 publications, spanning the last 150 years. -
(Alveolata) As Inferred from Hsp90 and Actin Phylogenies1
J. Phycol. 40, 341–350 (2004) r 2004 Phycological Society of America DOI: 10.1111/j.1529-8817.2004.03129.x EARLY EVOLUTIONARY HISTORY OF DINOFLAGELLATES AND APICOMPLEXANS (ALVEOLATA) AS INFERRED FROM HSP90 AND ACTIN PHYLOGENIES1 Brian S. Leander2 and Patrick J. Keeling Canadian Institute for Advanced Research, Program in Evolutionary Biology, Departments of Botany and Zoology, University of British Columbia, Vancouver, British Columbia, Canada Three extremely diverse groups of unicellular The Alveolata is one of the most biologically diverse eukaryotes comprise the Alveolata: ciliates, dino- supergroups of eukaryotic microorganisms, consisting flagellates, and apicomplexans. The vast phenotypic of ciliates, dinoflagellates, apicomplexans, and several distances between the three groups along with the minor lineages. Although molecular phylogenies un- enigmatic distribution of plastids and the economic equivocally support the monophyly of alveolates, and medical importance of several representative members of the group share only a few derived species (e.g. Plasmodium, Toxoplasma, Perkinsus, and morphological features, such as distinctive patterns of Pfiesteria) have stimulated a great deal of specula- cortical vesicles (syn. alveoli or amphiesmal vesicles) tion on the early evolutionary history of alveolates. subtending the plasma membrane and presumptive A robust phylogenetic framework for alveolate pinocytotic structures, called ‘‘micropores’’ (Cavalier- diversity will provide the context necessary for Smith 1993, Siddall et al. 1997, Patterson -
Introduction to Bacteriology and Bacterial Structure/Function
INTRODUCTION TO BACTERIOLOGY AND BACTERIAL STRUCTURE/FUNCTION LEARNING OBJECTIVES To describe historical landmarks of medical microbiology To describe Koch’s Postulates To describe the characteristic structures and chemical nature of cellular constituents that distinguish eukaryotic and prokaryotic cells To describe chemical, structural, and functional components of the bacterial cytoplasmic and outer membranes, cell wall and surface appendages To name the general structures, and polymers that make up bacterial cell walls To explain the differences between gram negative and gram positive cells To describe the chemical composition, function and serological classification as H antigen of bacterial flagella and how they differ from flagella of eucaryotic cells To describe the chemical composition and function of pili To explain the unique chemical composition of bacterial spores To list medically relevant bacteria that form spores To explain the function of spores in terms of chemical and heat resistance To describe characteristics of different types of membrane transport To describe the exact cellular location and serological classification as O antigen of Lipopolysaccharide (LPS) To explain how the structure of LPS confers antigenic specificity and toxicity To describe the exact cellular location of Lipid A To explain the term endotoxin in terms of its chemical composition and location in bacterial cells INTRODUCTION TO BACTERIOLOGY 1. Two main threads in the history of bacteriology: 1) the natural history of bacteria and 2) the contagious nature of infectious diseases, were united in the latter half of the 19th century. During that period many of the bacteria that cause human disease were identified and characterized. 2. Individual bacteria were first observed microscopically by Antony van Leeuwenhoek at the end of the 17th century. -
A Role for Crinophagy in Pancreatic Islet B-Cells Minireview Based on a Doctoral Thesis
Upsala J Med Sci 92: 99-1 13, 1987 A Role for Crinophagy in Pancreatic Islet B-cells Minireview based on a doctoral thesis Annika Schnell Landstrom Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden INTRODUCTORY REMARKS ON LYSOSOMES The lysosomes were first observed by Christian de Duve and his collaborators in December 1949 as "a cryptic form of latent acid phosphatase" (18). This observation lead to the suggestion that the enzyme could be located in a distinct group of subcellular granules, segregated from the rest of the cell by a limiting membrane. Further studies showed that these granules contained a number of acid hydrolases. The granules or bodies were thus supposed to have lytic properties and they were named lysosomes (18, 19). Soon after the discovery of the lysosome its role in cellular events such as intracellular digestion and phagocytosis was established. The presence of acid hydrolases, primarily acid phosphatase, as evidenced by enzyme cytochemistry, was the main criterium for morphological identification of a lysosome. In 1966 de Duve and Wattiaux (20) suggested a nomenclature for the lysosomal system, based in part on morphological criteria but mainly on the known functions of the lysosomes (Fig. 1). At that time the existence of some of the lysosomal particles was still under debate. The concept of primary lyso- somes, which had not yet taken part in intracellular degradation, was thus proposed. Lysosomes which had been involved in some kind of degradation were named secondary lysosomes. Depending on whether the secondary lysosomes were supposed to have been involved in either autophagy, i.e. -
Predatory Flagellates – the New Recently Discovered Deep Branches of the Eukaryotic Tree and Their Evolutionary and Ecological Significance
Protistology 14 (1), 15–22 (2020) Protistology Predatory flagellates – the new recently discovered deep branches of the eukaryotic tree and their evolutionary and ecological significance Denis V. Tikhonenkov Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, 152742, Russia | Submitted March 20, 2020 | Accepted April 6, 2020 | Summary Predatory protists are poorly studied, although they are often representing important deep-branching evolutionary lineages and new eukaryotic supergroups. This short review/opinion paper is inspired by the recent discoveries of various predatory flagellates, which form sister groups of the giant eukaryotic clusters on phylogenetic trees, and illustrate an ancestral state of one or another supergroup of eukaryotes. Here we discuss their evolutionary and ecological relevance and show that the study of such protists may be essential in addressing previously puzzling evolutionary problems, such as the origin of multicellular animals, the plastid spread trajectory, origins of photosynthesis and parasitism, evolution of mitochondrial genomes. Key words: evolution of eukaryotes, heterotrophic flagellates, mitochondrial genome, origin of animals, photosynthesis, predatory protists, tree of life Predatory flagellates and diversity of eu- of the hidden diversity of protists (Moon-van der karyotes Staay et al., 2000; López-García et al., 2001; Edg- comb et al., 2002; Massana et al., 2004; Richards The well-studied multicellular animals, plants and Bass, 2005; Tarbe et al., 2011; de Vargas et al., and fungi immediately come to mind when we hear 2015). In particular, several prevailing and very abun- the term “eukaryotes”. However, these groups of dant ribogroups such as MALV, MAST, MAOP, organisms represent a minority in the real diversity MAFO (marine alveolates, stramenopiles, opistho- of evolutionary lineages of eukaryotes. -
Extra-Intestinal Coccidians Plasmodium Species Distribution Of
Extra-intestinal coccidians Apicomplexa Coccidia Gregarinea Piroplasmida Eimeriida Haemosporida -Eimeriidae -Theileriidae -Haemosporiidae -Cryptosporidiidae - Babesiidae (Plasmodium) -Sarcocystidae (Sacrocystis) Aconoid (Toxoplasmsa) Plasmodium species Causitive agent of Malaria ~155 species named Infect birds, reptiles, rodents, primates, humans Species is specific for host and •P. falciparum vector •P. vivax 4 species cause human disease •P. malariae No zoonoses or animal reservoirs •P. ovale Transmission by Anopheles mosquito Distribution of Malarial Parasites P. vivax most widespread, found in most endemic areas including some temperate zones P. falciparum primarily tropics and subtropics P. malariae similar range as P. falciparum, but less common and patchy distribution P. ovale occurs primarily in tropical west Africa 1 Distribution of Malaria US Army, 1943 300 - 500 million cases per year 1.5 to 2.0 million deaths per year #1 cause of infant mortality in Africa! 40% of world’s population is at risk Malaria Atlas Map Project http://www.map.ox.ac.uk/index.htm 2 Malaria in the United States Malaria was quite prevalent in the rural South It was eradicated after world war II in an aggressive campaign using, treatment, vector control and exposure control Time magazine - 1947 (along with overall improvement of living Was a widely available, conditions) cheap insecticide This was the CDCs initial DDT resistance misssion Half-life in mammals - 8 years! US banned use of DDT in 1973 History of Malaria Considered to be the most