DOCSLIB.ORG

The Mating System of the Fungus Cryphonectria Parasitica: Sel®Ng and Self-Incompatibility

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Mating System of the Fungus Cryphonectria Parasitica: Sel®Ng and Self-Incompatibility 1 Heredity 86 (2001) 134±143 Received 6 June 2000, accepted 21 August 2000 The mating system of the fungus Cryphonectria parasitica: sel®ng and self-incompatibility ROBERT E. MARRA* & MICHAEL G. MILGROOM Department of Plant Pathology, 334 Plant Sciences Building, Cornell University, Ithaca NY 14853, U.S.A. Although the genetic components of mating systems in fungi are well understood as laboratory phenomena, surprisingly little is known about their function in nature or about their role in determining mating patterns and population genetic structure. Our study of the mating system of the haploid ascomycete fungus, Cryphonectria parasitica, resulted in the following. (1) Laboratory crosses among 20 isolates, chosen randomly from North America and China, resolved into two incompatibility groups (occurring on both continents), con®rming that C. parasitica has a diallelic, bipolar sexual self-incompatibility system, typical of other self-incompatible Ascomycetes, in which mating is only successful between isolates of opposite mating type. (2) PCR-based markers for mating-type alleles correlated perfectly with mating-type phenotypes of individual isolates. (3) Three genotypes, isolated from natural populations in Virginia and West Virginia, were inoculated onto chestnut trees in two sites in West Virginia and were con®rmed to have self-fertilized and outcrossed in both sites. (4) Ten isolates, of a total of over 200 assayed, were con®rmed to have self-fertilized in the laboratory, albeit at very low frequency. Five of these 10 isolates were ramets of a single genet, suggesting a genetic basis underlying the proclivity to self-fertilize in the laboratory. (5) Self- fertilization could not be induced in the laboratory with exudates (ostensibly containing pheromones) from isolates of opposite mating type. These results demonstrate that, a sexual self-incompatibility system notwithstanding, self-fertilization occurs under both laboratory and ®eld conditions in C. parasitica. The disparity between observations of frequent sel®ng in nature and rare sel®ng in the laboratory suggests that the mating system is under ecological as well as genetic control. Keywords: chestnut blight, Cryphonectria parasitica, fungus, mixed mating, self-fertilization, self- incompatibility. Introduction cinereus), spatial and temporal dynamics of fungal mating systems in nature remain relatively unstudied. Because of the near ubiquity of hermaphroditism in In those species where genetically determined self- plants and fungi, the phenomena of self-compatibility incompatibility has been identi®ed, it ranges from and self-incompatibility are central to studies of plant simple one-locus, two-allele systems to complex two- and fungal mating systems. However, in contrast to locus, multiallelic systems (Alexopoulos et al., 1996; more than a century of empirical and theoretical work p. 501). In the Ascomycota, sexual self-incompatibility is addressing plant mating systems (reviewed in Barrett, under the control of a single diallelic mating-type locus 1988; Barrett & Eckert, 1990; Jarne & Charlesworth, (MAT), which controls the fertilization process, and 1993; Richards, 1997), the majority of fungal mating subsequent steps in mating, as a regulator of diusable systems has yet to be investigated. Although a great deal and MAT-speci®c pheromones and receptors (Kues & of laboratory work has been focused on the mating Casselton, 1992). Ascomycete self-incompatibility is systems of a few fungi (e.g. Saccharomyces cerevisiae, considered `bipolar'; that is, mating only occurs between Neurospora crassa, Podospora anserina, and Coprinus individuals that have opposite alleles, or idiomorphs (MAT-1 and MAT-2) at this locus (Coppin et al., 1997; Kronstad & Staben, 1997). *Correspondence and present address: Department of Microbiology, With the exception of a few studies of ascomycete and Jones Building Box 3020, Duke University Medical Center, Durham basidiomycete species (Raper, 1966; Rayner & Turton, NC 27710, U.S.A., Tel: 919 684 9096, E-mail: [email protected] 134 Ó 2001 The Genetics Society of Great Britain. SELF-INCOMPATIBILITY IN CRYPHONECTRIA PARASITICA 135 1982; Ainsworth, 1987; Ennos & Swales, 1987; Leucht- were (1) to demonstrate and describe the self- mann & Clay, 1989; Sharland & Rayner, 1989a; incompatibility system in C. parasitica, and (2) to Sharland & Rayner, 1989b; Grin et al., 1992; Kohli determine if self-fertilization can in fact occur in the & Kohn, 1992), little is known about the manner or ®eld and laboratory. degree to which the mating systems of fungi, as characterized in the laboratory, determine genetic Study system structure in natural populations. The importance of studying fungal mating systems in both nature and the Cryphonectria parasitica, the ascomycete fungus that laboratory is demonstrated well by research on the causes chestnut blight, was introduced into North ascomycete Cryphonectria parasitica, a fungus patho- America from Japan around 1900 (Milgroom et al., genic on chestnut trees (Castanea dentata) in eastern 1996), and spread rapidly across the natural range of the North American forests. Mixed mating has been found American chestnut (Castanea dentata), which currently in ®ve populations in eastern North America, with persists as sprouts that regenerate from surviving root outcrossing rates (t) ranging from 0.68 to 0.73 (Marra, systems (reviewed in Anagnostakis, 1987). 1998; Milgroom et al., 1993). The life cycle of the typical ®lamentous ascomycete is The mating system of C. parasitica has so far eluded reviewed in Nelson (1996). C. parasitica infects chestnut simple classi®cation: both sel®ng and self-incompatibil- trees and forms cankers that produce two types of ity have been claimed, but neither has been suciently spores: asexual (conidia) and sexual (ascospores). documented. Signi®cant amounts of self-fertilization Conidia may function either as vegetative propagules occur in nature (see above), yet C. parasitica does not or as male gametes in sexual reproduction. Fertilization appear to self-fertilize readily in the laboratory (Marra, in C. parasitica (as well as many other ascomycetes) 1998; this study). A previous report of sel®ng in the occurs when a conidium and a receptive hypha (the laboratory (Puhalla & Anagnostakis, 1971) cannot be female reproductive structure) fuse to form a dikaryon considered conclusive, because controls for fertilization (n + n). Synchronous nuclear divisions result in a by contaminating male gametes (conidia) were not used, cluster of dikaryotic hyphae within the developing an essential control for demonstrating sel®ng unambig- fruit-body. Each terminal n + n cell (ascus initial) uously (Whitehouse, 1949). In marked contrast to the within the fruit-body undergoes karyogamy, resulting evidence for self-fertility in the ®eld, it has been in the brief diploid (2n) phase. Therefore, a single suggested (Anagnostakis, 1988) that C. parasitica is fertilization results in a fruitbody containing many 2n sexually self-incompatible, and recent work suggests cells. Each 2n nucleus undergoes meiosis, followed by a that C. parasitica may have a self-incompatibility locus single mitosis, resulting in eight ascospores per mature (MAT) similar to those of other self-incompatible ascus. In C. parasitica, and all other members of the ascomycetes (Marra & Milgroom, 1999). Class Pyrenomycetes, asci are borne inside a ¯ask- One explanation for this apparent contradiction is shaped fruit-body, the perithecium. Dispersal occurs that what appears to be sel®ng in nature is not actually when ascospores (there may be thousands per perithe- sel®ng, but biparental inbreeding to a degree that is cium) are forcibly ejected through an opening in the beyond the resolution of available markers. In this case, neck of the perithecium, which protrudes from the absence of marker segregation may not be diagnostic of surface of the canker. Each haploid ascospore is self-fertilization, but rather due to `eective' or `appar- dispersed by air currents, and is capable of infecting a ent' sel®ng (Hedrick, 1990). Spatial aggregation of tree and developing into a new canker, completing the genotypes (Milgroom & Lipari, 1995b), and biparental fungus's life cycle. inbreeding (Marra & Milgroom, 1994; Marra, 1998) suggest that some populations may actually comprise Materials and methods relatively restricted genetic neighbourhoods (Wright, 1946). These alternative explanations for lack of Strains and isolates used marker segregation require that the hypothesis that self-fertilization occurs in nature be tested rigorously. We used a combination of ®eld and laboratory-derived The possibility that a self-incompatible fungus is isolates of C. parasitica in this study. Unless otherwise capable of self-fertilization warrants further examina- speci®ed, ®eld isolates were collected from Mt. Lake, tion, and is the motivation for our interest in establish- Virginia (Milgroom et al., 1993); Danby, New York; ing the genetics underlying self-incompatibility in the Depot Hill, New York (Milgroom & Lipari, 1995a); and mating system in C. parasitica. However, because Parsons, West Virginia (Marra, 1998). Field isolates were neither self-fertilization nor self-incompatibility has obtained from bark samples (approx. 4 cm2) of chest- been suciently documented, our goals in this paper nut trees with visible blight cankers. New laboratory Ó The Genetics Society of Great Britain, Heredity, 86, 134±143. 136 R. E. MARRA & M. G. MILGROOM strains originated as ascospores
Load more

Recommended publications
  • CHESTNUT (CASTANEA Spp.) CULTIVAR EVALUATION for COMMERCIAL CHESTNUT PRODUCTION
    CHESTNUT (CASTANEA spp.) CULTIVAR EVALUATION FOR COMMERCIAL CHESTNUT PRODUCTION IN HAMILTON COUNTY, TENNESSEE By Ana Maria Metaxas Approved: James Hill Craddock Jennifer Boyd Professor of Biological Sciences Assistant Professor of Biological and Environmental Sciences (Director of Thesis) (Committee Member) Gregory Reighard Jeffery Elwell Professor of Horticulture Dean, College of Arts and Sciences (Committee Member) A. Jerald Ainsworth Dean of the Graduate School CHESTNUT (CASTANEA spp.) CULTIVAR EVALUATION FOR COMMERCIAL CHESTNUT PRODUCTION IN HAMILTON COUNTY, TENNESSEE by Ana Maria Metaxas A Thesis Submitted to the Faculty of the University of Tennessee at Chattanooga in Partial Fulfillment of the Requirements for the Degree of Master of Science in Environmental Science May 2013 ii ABSTRACT Chestnut cultivars were evaluated for their commercial applicability under the environmental conditions in Hamilton County, TN at 35°13ꞌ 45ꞌꞌ N 85° 00ꞌ 03.97ꞌꞌ W elevation 230 meters. In 2003 and 2004, 534 trees were planted, representing 64 different cultivars, varieties, and species. Twenty trees from each of 20 different cultivars were planted as five-tree plots in a randomized complete block design in four blocks of 100 trees each, amounting to 400 trees. The remaining 44 chestnut cultivars, varieties, and species served as a germplasm collection. These were planted in guard rows surrounding the four blocks in completely randomized, single-tree plots. In the analysis, we investigated our collection predominantly with the aim to: 1) discover the degree of acclimation of grower- recommended cultivars to southeastern Tennessee climatic conditions and 2) ascertain the cultivars’ ability to survive in the area with Cryphonectria parasitica and other chestnut diseases and pests present.
    [Show full text]
  • Cryphonectria Parasitica Global Invasive Species Database (GISD)
    FULL ACCOUNT FOR: Cryphonectria parasitica Cryphonectria parasitica System: Terrestrial Kingdom Phylum Class Order Family Fungi Ascomycota Sordariomycetes Diaporthales Valsaceae Common name Edelkastanienkrebs (German), chestnut blight (English) Synonym Endothia parasitica Similar species Cryphonectria radicalis, Endothia gyrosa Summary Cryphonectria parasitica is a fungus that attacks primarily Castanea spp. but also has been known to cause damage to various Quercus spp. along with other species of hardwood trees. American chestnut, C. dentata, was a dominant overstorey species in United States forests, but now they have been completely replaced within the ecosystem. C. dentata still exists in the forests but only within the understorey as sprout shoots from the root system of chestnuts killed by the blight years ago. A virus that attacks this fungus appears to be the best hope for the future of Castanea spp., and current research is focused primarily on this virus and variants of it for biological control. Chestnut blight only infects the above-ground parts of trees, causing cankers that enlarge, girdle and kill branches and trunks. view this species on IUCN Red List Global Invasive Species Database (GISD) 2021. Species profile Cryphonectria Pag. 1 parasitica. Available from: http://www.iucngisd.org/gisd/species.php?sc=124 [Accessed 05 October 2021] FULL ACCOUNT FOR: Cryphonectria parasitica Species Description The US Forest Service (undated) states that, \"C. parasitica forms yellowish or orange fruiting bodies (pycnidia) about the size of a pin head on the older portion of cankers. Spores may exude from the pycnidia as orange, curled horns during moist weather. Stem cankers are either swollen or sunken, and the sunken type may be grown over with bark.
    [Show full text]
  • Evolution of Genetic Systems in Filamentous Ascomycetes
    Evolution of Genetic Systems in Filamentous Ascomycetes Evolutie van genetische systemen in hyphenvormende zakjeszwammen 0000 0513 3836 Promotor: dr. R.F. Hoekstra hoogleraar in de populatie- en kwantitatieve genetica fjtfoiißi f ßin Maarten J. Nauta Evolution of Genetic Systems in Filamentous Ascomycetes Proefschrift ter verkrijging van de graad van doctor in de landbouw- en milieuwetenschappen op gezag van de rector magnificus, dr. C.M. Karssen, in het openbaar te verdedigen op woensdag 12januar i 1994 des namiddags te vier uur in de Aula van de Landbouwuniversiteit te Wageningen. 15 0 S(p^ZJ> These investigations were supported by the Netherlands Organization for Scientific Research (N.W.O.). BibUt/FHEEK LAMDbOirWUNIVERSITEJi. WAGE NINGE N CIP-GEGEVENS KONINKLIJKE BIBLIOTHEEK, DEN HAAG Nauta, Maarten J. Evolution of genetic systems in filamentous ascomycetes / Maarten J. Nauta. - [ S.l. : s.n.]. -111 . Thesis Wageningen. - With ref. - With summary in Dutch. ISBN 90-5485-199-6 Subject headings: population genetics / ascomycetes. omslagontwerp: Ernst van Cleef foto omslag: Barrages tussen verschillende stammen van Podospora anserina als gevolg van vegetatieve incompatibiliteit. (met dank aan Inge Haspels) aan mijn ouders Voorwoord Dit proefschrift is het resultaat van vier jaar onderzoek, verricht bij de vakgroep Erfelijkheidsleer van de Landbouwuniversiteit in Wageningen. In zekere zin valt zo'n proefschrift te vergelijken met een levend wezen. Uit de genetica is bekend dat de verschijningsvorm van elk levend wezen tot stand komt door een combinatie van erfelijke aanleg en invloeden uit de omgeving. Voor een proefschrift geldt eigenlijk hetzelfde: Zowel het werk van de auteur, als de bijdragen van zijn omgeving zijn onontbeerlijk om tot een verschijningsvorm te komen.
    [Show full text]
  • Evolutionary Pathways to Self-Fertilization in a Tristylous Plant
    Review BlackwellOxford,NPHNew0028-646X1469-8137©293710.1111/j.1469-8137.2009.02937.xJune0546???556???ResearchXX The 2009Phytologist Authors UK Review Publishing (2009). Ltd Journal compilation © New Phytologist (2009) Research reviewXX Evolutionary pathways to self- fertilization in a tristylous plant species Author for correspondence: Spencer C. H. Barrett, Rob W. Ness and Mario Vallejo-Marín Spencer C. H. Barrett Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, Tel: +1 416 978 5603 Email: [email protected] Ontario, Canada, M5S 3B2 Received: 23 April 2009 Accepted: 20 May 2009 Summary New Phytologist (2009) 183: 546–556 Evolutionary transitions from outcrossing to selfing occur commonly in heterostylous doi: 10.1111/j.1469-8137.2009.02937.x genera. The morphological polymorphisms that characterize heterostyly provide opportunities for different pathways for selfing to evolve. Here, we investigate the Key words: developmental instability, origins and pathways by which selfing has evolved in tristylous Eichhornia paniculata Eichhornia, herkogamy, heterostyly, multiple by providing new evidence based on morphology, DNA sequences and genetic analysis. origins, pathways to self-fertilization. The primary pathway from outcrossing to selfing involves the stochastic loss of the short-styled morph (S-morph) from trimorphic populations, followed by the spread of selfing variants of the mid-styled morph (M-morph). However, the discovery of selfing variants of the long-styled morph (L-morph) in Central America indicates a secondary pathway and distinct origin for selfing. Comparisons of multi-locus nucleo- tide sequences from 27 populations sampled from throughout the geographical range suggest multiple transitions to selfing. Genetic analysis of selfing variants of the L- and M-morphs demonstrates recessive control of the loss of herkogamy, although the number of factors appears to differ between the forms.
    [Show full text]
  • 1E5o Lichtarge Lab 2006
    Pages 1–7 1e5o Evolutionary trace report by report maker September 20, 2008 4.3.1 Alistat 6 4.3.2 CE 7 4.3.3 DSSP 7 4.3.4 HSSP 7 4.3.5 LaTex 7 4.3.6 Muscle 7 4.3.7 Pymol 7 4.4 Note about ET Viewer 7 4.5 Citing this work 7 4.6 About report maker 7 4.7 Attachments 7 1 INTRODUCTION From the original Protein Data Bank entry (PDB id 1e5o): Title: Endothiapepsin complex with inhibitor db2 Compound: Mol id: 1; molecule: endothiapepsin; chain: e; frag- ment: residue 90-419; ec: 3.4.23.23; mol id: 2; molecule: endothia- pepsin inhibitor; chain: i Organism, scientific name: Endothia Parasitica; 1e5o contains a single unique chain 1e5oE (330 residues long). Chain 1e5oI is too short (4 residues) to permit statistically significant CONTENTS analysis, and was treated as a peptide ligand. 1 Introduction 1 2 CHAIN 1E5OE 2.1 P11838 overview 2 Chain 1e5oE 1 2.1 P11838 overview 1 From SwissProt, id P11838, 90% identical to 1e5oE: 2.2 Multiple sequence alignment for 1e5oE 1 Description: Endothiapepsin precursor (EC 3.4.23.22) (Aspartate 2.3 Residue ranking in 1e5oE 1 protease). 2.4 Top ranking residues in 1e5oE and their position on Organism, scientific name: Cryphonectria parasitica (Chesnut the structure 2 blight fungus) (Endothia parasitica). 2.4.1 Clustering of residues at 25% coverage. 2 Taxonomy: Eukaryota; Fungi; Ascomycota; Pezizomycotina; 2.4.2 Overlap with known functional surfaces at Sordariomycetes; Sordariomycetidae; Diaporthales; Valsaceae; 25% coverage. 3 Cryphonectria-Endothia complex; Cryphonectria.
    [Show full text]
  • Genetic Diversity in Partially Selfing Populations with the Stepping-Stone Structure
    Heredity 77 (1996) 469—475 Received 20 October 1995 Genetic diversity in partially selfing populations with the stepping-stone structure HIDENORI TACHIDA*t & HIROSHI YOSHIMARU tDepartment of Biology, Faculty of Science, Kyushu University 33, Fukuoka 812, Japan and tPopulation Genetics Laboratory, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305, Japan Amethod to compute identity coefficients of two genes in the stepping-stone model with partial selfing is developed. The identity coefficients in partially selfing populations are computed from those in populations without selfing as functions of s (selfing rate), m (migra- tion rate), N (subpopulation size), n (number of subpopulations) and u (mutation rate). For small m, 1/N and u, it is shown that approximate formulae for the identity coefficients of two genes from different individuals are the same as those in random mating populations if we replace N in the latter with N(1 —s12).Thus,the effects of selfing on genetic variability are summarized as reducing variation within subpopulations and increasing differentiation among subpopulations by reducing the subpopulation size. The extent of biparental inbreeding as measured by the genotypic correlation between truly outcrossed mates was computed in the one-dimensional stepping-stone model. The correlation was shown to be independent of the selfing rate and starts to fall off as the migration rate increases when mN is larger than 0.1. Keywords:biparentalinbreeding, fixation index, genetic variability, geographical differentia- tion, selfing, stepping-stone model. Introduction Model analysis Manyplant species are partially self-fertilizing Genesare defined to be identical by descent if they (Brown, 1990; Murawski & Hamrick, 1991, 1992; have a common ancestor gene and there is no muta- Kitamura et a!., 1994).
    [Show full text]
  • A Five-Gene Phylogeny of Pezizomycotina
    Mycologia, 98(6), 2006, pp. 1018–1028. # 2006 by The Mycological Society of America, Lawrence, KS 66044-8897 A five-gene phylogeny of Pezizomycotina Joseph W. Spatafora1 Burkhard Bu¨del Gi-Ho Sung Alexandra Rauhut Desiree Johnson Department of Biology, University of Kaiserslautern, Cedar Hesse Kaiserslautern, Germany Benjamin O’Rourke David Hewitt Maryna Serdani Harvard University Herbaria, Harvard University, Robert Spotts Cambridge, Massachusetts 02138 Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331 Wendy A. Untereiner Department of Botany, Brandon University, Brandon, Franc¸ois Lutzoni Manitoba, Canada Vale´rie Hofstetter Jolanta Miadlikowska Mariette S. Cole Vale´rie Reeb 2017 Thure Avenue, St Paul, Minnesota 55116 Ce´cile Gueidan Christoph Scheidegger Emily Fraker Swiss Federal Institute for Forest, Snow and Landscape Department of Biology, Duke University, Box 90338, Research, WSL Zu¨ rcherstr. 111CH-8903 Birmensdorf, Durham, North Carolina 27708 Switzerland Thorsten Lumbsch Matthias Schultz Robert Lu¨cking Biozentrum Klein Flottbek und Botanischer Garten der Imke Schmitt Universita¨t Hamburg, Systematik der Pflanzen Ohnhorststr. 18, D-22609 Hamburg, Germany Kentaro Hosaka Department of Botany, Field Museum of Natural Harrie Sipman History, Chicago, Illinois 60605 Botanischer Garten und Botanisches Museum Berlin- Dahlem, Freie Universita¨t Berlin, Ko¨nigin-Luise-Straße Andre´ Aptroot 6-8, D-14195 Berlin, Germany ABL Herbarium, G.V.D. Veenstraat 107, NL-3762 XK Soest, The Netherlands Conrad L. Schoch Department of Botany and Plant Pathology, Oregon Claude Roux State University, Corvallis, Oregon 97331 Chemin des Vignes vieilles, FR - 84120 MIRABEAU, France Andrew N. Miller Abstract: Pezizomycotina is the largest subphylum of Illinois Natural History Survey, Center for Biodiversity, Ascomycota and includes the vast majority of filamen- Champaign, Illinois 61820 tous, ascoma-producing species.
    [Show full text]
  • Inbreeding Depression in Two Populations of Arenaria Uni¯Ora (Caryophyllaceae) with Contrasting Mating Systems
    Heredity 86 (2001) 184±194 Received 16 November 1999, accepted 17 October 2000 Inbreeding depression in two populations of Arenaria uni¯ora (Caryophyllaceae) with contrasting mating systems LILA FISHMAN Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544 U.S.A. I used parallel family-structured crossing designs to investigate the relative performance of self and outcross progeny in sel®ng and predominantly outcrossing populations of the annual plant Arenaria uni¯ora. The selfer population experienced much lower inbreeding depression (d 0.05 0.02 SE) than the outcrossers (d 0.19 0.02 SE). The negative association between genetic load and sel®ng rate suggests that purgable partially recessive alleles are the primary source of inbreeding depression, as does its late expression in both populations. Inbreeding depression in the selfer population, which naturally consists of highly inbred lines, was used to calculate the mean dominance (h 0.33) and incidence rate (U 0.30) of deleterious mutations. In the outcrosser population, signi®cant variation among individuals in the expression of inbreeding depression may re¯ect lineage-speci®c dierences in inbreeding history or, more probably, random variation in mutational load. The low (0.5) inbreeding depression of outcrossers suggests that the maintenance of a mixed mating system in some A. uni¯ora populations and the evolution of nearly cleistogamous self-pollination in others may re¯ect local pollinator-mediated selection for sel®ng rather than the constant 3:2 genetic advantage invoked by many models. Keywords: Arenaria uni¯ora, genetic load, inbreeding depression, mating system, sel®ng.
    [Show full text]
  • The Chestnut Blight Fungus for Studies on Virus/Host and Virus/Virus Interactions: from a Natural to a Model Host
    Virology 477 (2015) 164–175 Contents lists available at ScienceDirect Virology journal homepage: www.elsevier.com/locate/yviro The chestnut blight fungus for studies on virus/host and virus/virus interactions: From a natural to a model host Ana Eusebio-Cope a, Liying Sun b, Toru Tanaka a, Sotaro Chiba a, Shin Kasahara c, Nobuhiro Suzuki a,n a Institute of Plant Science and Resources (IPSR), Okayama University, Chuou 2-20-1, Kurashiki, Okayama 710-0046, Japan b College of Plant Protection, Northwest A & F University, Yangling, Shananxi, China c Department of Environmental Sciences, Miyagi University, Sendai 982-215, Japan article info abstract Article history: The chestnut blight fungus, Cryphonectria parasitica, is an important plant pathogenic ascomycete. The Received 16 August 2014 fungus hosts a wide range of viruses and now has been established as a model filamentous fungus for Returned to author for revisions studying virus/host and virus/virus interactions. This is based on the development of methods for 15 September 2014 artificial virus introduction and elimination, host genome manipulability, available host genome Accepted 26 September 2014 sequence with annotations, host mutant strains, and molecular tools. Molecular tools include sub- Available online 4 November 2014 cellular distribution markers, gene expression reporters, and vectors with regulatable promoters that Keywords: have been long available for unicellular organisms, cultured cells, individuals of animals and plants, and Cryphonectria parasitica certain filamentous fungi. A comparison with other filamentous fungi such as Neurospora crassa has been Chestnut blight fungus made to establish clear advantages and disadvantages of C. parasitica as a virus host. In addition, a few dsRNA recent studies on RNA silencing vs.
    [Show full text]
  • Population Genetics of the Wild Yeast Saccharomyces Paradoxus
    Copyright 2004 by the Genetics Society of America Population Genetics of the Wild Yeast Saccharomyces paradoxus Louise J. Johnson,*,1 Vassiliki Koufopanou,* Matthew R. Goddard,† Richard Hetherington,* Stefanie M. Scha¨fer*,2 and Austin Burt* *Department of Biological Sciences and †NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot SL5 7PY, United Kingdom Manuscript received November 4, 2002 Accepted for publication September 22, 2003 ABSTRACT Saccharomyces paradoxus is the closest known relative of the well-known S. cerevisiae and an attractive model organism for population genetic and genomic studies. Here we characterize a set of 28 wild isolates from a 10-km2 sampling area in southern England. All 28 isolates are homothallic (capable of mating-type switching) and wild type with respect to nutrient requirements. Nine wild isolates and two lab strains of S. paradoxus were surveyed for sequence variation at six loci totaling 7 kb, and all 28 wild isolates were then genotyped at seven polymorphic loci. These data were used to calculate nucleotide diversity and number of segregating sites in S. paradoxus and to investigate geographic differentiation, population Extensive incompatibilities .%0.3ف structure, and linkage disequilibrium. Synonymous site diversity is between gene genealogies indicate frequent recombination between unlinked loci, but there is no evidence of recombination within genes. Some localized clonal growth is apparent. The frequency of outcrossing relative to inbreeding is estimated at 1.1% on the basis of heterozygosity. Thus, all three modes of reproduction known in the lab (clonal replication, inbreeding, and outcrossing) have been important in molding genetic variation in this species.
    [Show full text]
  • NDP 11 V2 - National Diagnostic Protocol for Cryphonectria Parasitica
    NDP 11 V2 - National Diagnostic Protocol for Cryphonectria parasitica National Diagnostic Protocol Chestnut blight Caused by Cryphonectria parasitica NDP 11 V2 NDP 11 V2 - National Diagnostic Protocol for Cryphonectria parasitica © Commonwealth of Australia Ownership of intellectual property rights Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this publication is owned by the Commonwealth of Australia (referred to as the Commonwealth). Creative Commons licence All material in this publication is licensed under a Creative Commons Attribution 3.0 Australia Licence, save for content supplied by third parties, logos and the Commonwealth Coat of Arms. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided you attribute the work. A summary of the licence terms is available from http://creativecommons.org/licenses/by/3.0/au/deed.en. The full licence terms are available from https://creativecommons.org/licenses/by/3.0/au/legalcode. This publication (and any material sourced from it) should be attributed as: Subcommittee on Plant Health Diagnostics (2017). National Diagnostic Protocol for Cryphonectria parasitica – NDP11 V2. (Eds. Subcommittee on Plant Health Diagnostics) Authors Cunnington, J, Mohammed, C and Glen, M. Reviewers Pascoe, I and Tan YP, ISBN 978-0- 9945113-6-2. CC BY 3.0. Cataloguing data Subcommittee on Plant Health Diagnostics (2017). National Diagnostic Protocol for Cryphonectria parasitica – NDP11 V2. (Eds. Subcommittee on Plant Health Diagnostics) Authors Cunnington, J, Mohammed, C and Glen, M. Reviewers Pascoe, I and Tan YP, ISBN 978-0-9945113-6-2.
    [Show full text]
  • Restoration of the American Chestnut in New Jersey
    U.S. Fish & Wildlife Service Restoration of the American Chestnut in New Jersey The American chestnut (Castanea dentata) is a tree native to New Jersey that once grew from Maine to Mississippi and as far west as Indiana and Tennessee. This tree with wide-spreading branches and a deep broad-rounded crown can live 500-800 years and reach a height of 100 feet and a diameter of more than 10 feet. Once estimated at 4 billion trees, the American chestnut Harvested chestnuts, early 1900's. has almost been extirpated in the last 100 years. The U.S. Fish and Wildlife Service, New Jersey Field Value Office (Service) and its partners, including American Chestnut The American chestnut is valued Cooperators’ Foundation, American for its fruit and lumber. Chestnuts Chestnut Foundation, Monmouth are referred to as the “bread County Parks, Bayside State tree” because their nuts are Prison, Natural Lands Trust, and so high in starch that they can several volunteers, are working to American chestnut leaf (4"-8"). be milled into flour. Chestnuts recover the American chestnut in can be roasted, boiled, dried, or New Jersey. History candied. The nuts that fell to the ground were an important cash Chestnuts have a long history of crop for families in the northeast cultivation and use. The European U.S. and southern Appalachians chestnut (Castanea sativa) formed up until the twentieth century. the basis of a vital economy in Chestnuts were taken into towns the Mediterranean Basin during by wagonload and then shipped Roman times. More recently, by train to major markets in New areas in Southern Europe (such as York, Boston, and Philadelphia.
    [Show full text]