DOCSLIB.ORG

Cold Shock D. Melanogaster

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cold Shock D. Melanogaster Cold tolerance in Sonoran Desert Drosophilaspecies Item Type text; Thesis-Reproduction (electronic) Authors Cleaves, Lawrence Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 03/10/2021 09:26:39 Link to Item http://hdl.handle.net/10150/291510 INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may t)e from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough. substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author dkl not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overiaps. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6' x 9' black and white photographs prints are available for any photographs or illustrations appearing in this copy for an additkmal charge. Contact UMI directly to order. ProQuest Informatkm and Learning 300 North Zeeb Road. Ann Art)or, Ml 48106-1346 USA 800-521-0600 COLD TOLERANCE IN SONORAN DESERT DROSOPHILA SPECIES by Lawrence Scott Cleaves Copyright © Lawrence Scott Cleaves 2002 A Thesis Submitted to the Faculty of the DEPARTMENT OF BIOCHEMISTRY AND MOLECULAR BIOPHYSICS In Partial Fulflllnient of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN GENERAL BIOLOGY In the Graduate College THE UNIVERSITY OF ARLZONA 2002 UMI Number; 1409486 Copyright 2002 by Cleaves, Lawrence Scott All rights reserved. ® UMI UMI Microform 1409486 Copyright 2002 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Infomiation and Leaming Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation fixim or reproduction of this manuscript in whole or in part may be granted by the copyright holder. SIGNED: APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: 3 TABLE OF CONTENTS ABSTRACT 6 INTRODUCTION AND HISTORICAL PERSPECTIVE 7 SPECIES UTILIZED IN THIS STUDY 13 MATERIALS AND METHODS 20 RESULTS 26 DISCUSSION 49 ACKNOWLEDGMENT 60 REFERENCES 61 4 LIST OF TABLES AND ILLUSTRATIONS TABLE 1, Drosophila Species Used in This Study 18 TABLE 2, Taxonomy of Drosophila Species Used in This Study 21 TABLE 3, Cold Shock Response in Drosophila Species 27 TABLE 4, Rapid Cold Hardening Response in Drosophila Species 35 TABLE 5, Prolonged Exposure at 0°C Response in Drosophila Species 39 FIGURE 1, Representative Phylogeny of Drosophila 19 FIGURE 2, Cold Baths Used in Experiments 22 FIG. 2a: Ice Bath with Circulator FIG. 2b: Sub-zero Water/Anti-freeze Bath FIGURES 3-9, Cold Shock graphs FIG 3: D. pseudoobscura 28 FIG. 4: D. melanogaster 29 FIG. 5: D. hydeii 30 FIG. 6: D. mettleri 31 FIG. 7; D. mojavensis 32 FIG. 8: D. niff'ospiracula 33 FIG. 9: D. paulistorum 34 FIGURES 10-11, Rapid Cold Hardening graphs FIG. 10; Males for five species 37 FIG. 11: Females for five species 38 5 LIST OF ILLUSTRATIONS - continued FIGURES 12-17, Prolonged Exposure at 0°C graphs FIG. 12: D. pseudoobscura 40 FIG. 13: D. melanogaster 41 FIG. 14: D. hydei 42 FIG. 15: D. metlleri 43 FIG. 16: D. mojavensis 44 FIG. 17: D. paulistorum 45 FIGURES 18-19, Prolonged Exposure at 0°C Comparison graphs FIG. 18: Males for six species 46 FIG. 19: Females for six species 47 6 ABSTRACT I examined resistance to cold temperature in seven Drosophila species from different habitats to determine the lower limits of cold tolerance. Three separate tests were administered to measure the; 1) response to a cold-shock exposure; 2) extent to which a short-term survival strategy, rapid cold hardening, was utilized by each species; and 3) degree to which each species would respond to a prolonged exposure at 0°C. As expected, the temperate-montane species, D. pseudoobscura, was the most cold-tolerant, whereas the least cold-tolerant was the tropical species, D. paulistorum. The two cosmopolitan species, D. hydei and D. melanogaster, and the three Sonoran Desert endemic species, D. mojavensis, D. nigrospiracula, and D. mettleri, demonstrated intermediate levels of cold-tolerance. Of the five species tested for rapid cold hardening, all exhibited the response, including the tropical representative. The results for the 0°C test paralleled the results of the cold shock test. The desert species tested proved surprisingly cold-tolerant, especially D. mojavensis. 7 INTRODUCTION AND HISTORICAL PERSPECTIVE Introduction Temperature is the most important abiotic factor affecting the survival and distribution of insects world-wide (Andrewartha and Birch 1954; Cohet et. al 1980; Morin et al. 1997), and a great deal of work has been focused on the topic, particularly in the last 50 years. Some of the fundamental questions in thermal biology include: How do insects adapt to and survive the stresses of temperature extremes? What role has temperature played in the ecology and evolution of species? What are the biochemical and physiological mechanisms insects use to tolerate high and low temperatures? What impact does temperature have on insect development, reproductive capacity, and behavior? This paper addresses the first two questions above in relation to cold tolerance in various Drosophila species. Although significandy more research has focused on the effects of high temperature on insects (Levins 1969; Denlinger et al. 1991; Heinrich 1993; Stratman and Markow 1998; Feder and Hoffman 1999), the last few decades have produced numerous investigations concerning the effects of cold temperature (Parsons 1977; Lee 1989; Lee and Denlinger 1991; Chen and Walker 1994; Gibert et al. 2001). Recent studies on Drosophila have attempted to identity cold tolerance parameters for a number of species firom a variety of habitats (Cohet et al. 1980; Stanley et al. 1980; Yamamoto and Ohba 1984a, 1984b; Kimura 1988; Hoffman and Watson 1993; Gibert and Huey 2001; Gibert 8 et al. 2001). One group which has not received much investigative attention for cold tolerance, however, is the desert species, which may experience severe frosts during winter months as well as rapid changes in diurnal temperature (Lowe et al. 1967; Heed 1982). The primary purpose of this study is to compare levels of cold tolerance in three species of desert Drosophila with four other species from the same genus, including one temperate, two cosmopolitan, and one tropical representative. Historical Perspective Serious investigations in cryobiology began in the mid-19"* century when research focused on the economic importance of producing frost-hardy plant crops (Payne 1926). Between the latter part of the 19''' and the middle of the 20"* century, insects became popular as subjects of cryobiology research not only because of their obvious impact on plants, but also because of a growing interest in determining the effect of low temperature on insect ecology, geographic distribution, and behavior (Salt 1936, 1950,1956; Novitski and Rush 1949; Knipling and Sullivan 1957). Since the 1950's, investigations in cryobiology have included a wide variety of other poikilothermic organisms (Block 1982; Zachariassen 1982; Storey and Storey 1988; Loomis 1991) as well as a substantial broadening of research topics. On insects alone, the last 50 years have produced studies which have investigated the genetic and cellular basis for cold tolerance (Marinkovic et al. 1969; Parsons 1973; Tucic 1979; Ring 1980; Lee et al. 1996); specific physiological and biochemical mechanisms that promote cold tolerance (Salt 1961; Somme 1982; Zachariassen 1985; Lee 1991; Storey and Storey 1991); implications for cryopreservation 9 (Morris 1987; Leopold 1991; Steponkus et al. 1991); potential for using insect cold tolerance data as a tool for pest management practices (e.g. long-term population forecasting and the application of natural pesticides which lower insect resistance to colder temperatures) (Bale 1991, Lee et al. 1993); and ecological and evolutionary basis for cold adaptation (Baust and Rojas 1985; Bale 1987; Danks 1978, 1991; Somme and Block 1991). During the past three decades in particular, the ecological and evolutionary basis for cold adaptation in insects has received increasingly significant attention. Many investigations have attempted to correlate laboratory results with conditions in nature to establish ecological relevance (Parsons 1978; Hori and Kimura 1998; David et al. 1998; Kelty and Lee 1999, 2001; Gibert and Huey 2001; Gibert et al. 2001). For example, researchers have assessed cold tolerance in a wide range of species in a variety of developmental stages to better understand overwintering strategies and distribution patterns (Izquierdo 1991; Kimura and Beppu 1993; Kimura et al. 1994; Collett and Jarman 2001). Furthermore, recent studies have more closely examined both short and long-term acclimation responses (Lee et al.
Load more

Recommended publications
  • Behavioral Evolution Accompanying Host Shifts in Cactophilic Drosophila Larvae
    Behavioral evolution accompanying host shifts in cactophilic Drosophila larvae Item Type Article Authors Coleman, Joshua M.; Benowitz, Kyle M.; Jost, Alexandra G.; Matzkin, Luciano M. Citation Coleman JM, Benowitz KM, Jost AG, Matzkin LM. Behavioral evolution accompanying host shifts in cactophilic Drosophila larvae. Ecol Evol. 2018;8:6921–6931. https://doi.org/10.1002/ ece3.4209 DOI 10.1002/ece3.4209 Publisher WILEY Journal ECOLOGY AND EVOLUTION Rights © 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License. Download date 05/10/2021 08:39:04 Item License https://creativecommons.org/licenses/by/4.0/ Version Final published version Link to Item http://hdl.handle.net/10150/631224 Received: 2 March 2018 | Revised: 16 April 2018 | Accepted: 17 April 2018 DOI: 10.1002/ece3.4209 ORIGINAL RESEARCH Behavioral evolution accompanying host shifts in cactophilic Drosophila larvae Joshua M. Coleman1,2 | Kyle M. Benowitz1 | Alexandra G. Jost2 | Luciano M. Matzkin1,3,4 1Department of Entomology, University of Arizona, Tucson, Arizona Abstract 2Department of Biological For plant utilizing insects, the shift to a novel host is generally accompanied by a Sciences, University of Alabama in complex set of phenotypic adaptations. Many such adaptations arise in response to Huntsville, Huntsville, Alabama differences in plant chemistry, competitive environment, or abiotic conditions. One 3BIO5 Institute, University of Arizona, Tucson, Arizona less well- understood factor in the evolution of phytophagous insects is the selective 4Department of Ecology and Evolutionary environment provided by plant shape and volume. Does the physical structure of a Biology, University of Arizona, Tucson, Arizona new plant host favor certain phenotypes? Here, we use cactophilic Drosophila, which have colonized the necrotic tissues of cacti with dramatically different shapes and Correspondence Luciano M.
    [Show full text]
  • A Comparison of Behavioural Change in Drosophila During Exposure to Thermal Stress
    Cleveland State University EngagedScholarship@CSU Biological, Geological, and Environmental Biological, Geological, and Environmental Faculty Publications Sciences Department 10-2004 A Comparison of Behavioural Change in Drosophila During Exposure to Thermal Stress Angel G. Fasolo Cleveland State University Robert A. Krebs Cleveland State University, [email protected] Follow this and additional works at: https://engagedscholarship.csuohio.edu/scibges_facpub Part of the Biodiversity Commons, and the Biology Commons How does access to this work benefit ou?y Let us know! Publisher's Statement This is the accepted version of the following article: Fasolo AG and Krebs RA. 2004. A comparison of behavioural change in drosophila during exposure to thermal stress. Biol J Linn Soc 83(2):197-205., which has been published in final form at http://onlinelibrary.wiley.com/doi/ 10.1111/j.1095-8312.2004.00380.x/abstract Recommended Citation Fasolo AG and Krebs RA. 2004. A comparison of behavioural change in drosophila during exposure to thermal stress. Biol J Linn Soc 83(2):197-205. This Article is brought to you for free and open access by the Biological, Geological, and Environmental Sciences Department at EngagedScholarship@CSU. It has been accepted for inclusion in Biological, Geological, and Environmental Faculty Publications by an authorized administrator of EngagedScholarship@CSU. For more information, please contact [email protected]. Blackwell Science, LtdOxford, UKBIJBiological Journal of the Linnean Society0024-4066The Linnean Society of London, 2004? 2004 832 197205 Original Article A comparison of behavioural change in Drosophila during exposure to thermal stress ANGEL G. FASOLO and ROBERT A. KREBS* Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Ave, Cleveland, OH 44115, USA In order to understand how adaptive tolerance to stress has evolved, we compared related species and populations of Drosophila for a variety of fitness relevant traits while flies directly experienced the stress.
    [Show full text]
  • Comparative Transcriptomics Between Drosophila Mojavensis and D
    www.nature.com/scientificreports OPEN Comparative transcriptomics between Drosophila mojavensis and D. arizonae reveals transgressive gene expression and underexpression of spermatogenesis‑related genes in hybrid testes Cecilia A. Banho1,2, Vincent Mérel2, Thiago Y. K. Oliveira3, Claudia M. A. Carareto1 & Cristina Vieira2* Interspecifc hybridization is a stressful condition that can lead to sterility and/or inviability through improper gene regulation in Drosophila species with a high divergence time. However, the extent of these abnormalities in hybrids of recently diverging species is not well known. Some studies have shown that in Drosophila, the mechanisms of postzygotic isolation may evolve more rapidly in males than in females and that the degree of viability and sterility is associated with the genetic distance between species. Here, we used transcriptomic comparisons between two Drosophila mojavensis subspecies and D. arizonae (repleta group, Drosophila) and identifed greater diferential gene expression in testes than in ovaries. We tested the hypothesis that the severity of the interspecies hybrid phenotype is associated with the degree of gene misregulation. We showed limited gene misregulation in fertile females and an increase in the amount of misregulation in males with more severe sterile phenotypes (motile vs. amotile sperm). In addition, for these hybrids, we identifed candidate genes that were mostly associated with spermatogenesis dysfunction. Speciation is a complex process resulting from the divergence of two populations from an ancestral lineage by reproductive barriers capable of preventing gene fow 1,2. Among these barriers, postzygotic isolation mechanisms contribute to hybrid incompatibility, and their consequences can be observed by the presence of two main traits, hybrid sterility and/or hybrid inviability, which can evolve at diferent rates.
    [Show full text]
  • Transcriptional Regulation of Metabolism Associated with the Increased Desiccation Resistance of the Cactophilic Drosophila Mojavensis
    Copyright Ó 2009 by the Genetics Society of America DOI: 10.1534/genetics.109.104927 Transcriptional Regulation of Metabolism Associated With the Increased Desiccation Resistance of the Cactophilic Drosophila mojavensis Luciano M. Matzkin1 and Therese A. Markow2 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721-0088 Manuscript received May 9, 2009 Accepted for publication May 19, 2009 ABSTRACT In Drosophila, adaptation to xeric environments presents many challenges, greatest among them the maintenance of water balance. Drosophila mojavensis, a cactophilic species from the deserts of North America, is one of the most desiccation resistant in the genus, surviving low humidity primarily by reducing its metabolic rate. Genetic control of reduced metabolic rate, however, has yet to be elucidated. We utilized the recently sequenced genome of D. mojavensis to create an oligonucleotide microarray to pursue the identities of the genes involved in metabolic regulation during desiccation. We observed large differences in gene expression between male and female D. mojavensis as well as both quantitative and qualitative sex differences in their ability to survive xeric conditions. As expected, genes associated with metabolic regulation and carbohydrate metabolism were differentially regulated between stress treatments. Most importantly, we identified four points in central metabolism (Glyceraldehyde 3-phosphate dehydrogenase, transaldolase, alcohol dehydrogenase, and phosphoenolpyruvate carboxykinase) that
    [Show full text]
  • Asymmetry of the Wing in Drosophila Mojavensis Sonorensis Castrezana in Pfeiler Et Al., 2009 (Diptera, Drosophilidae): Main Versus Seasonal Host
    ISSN 1519-6984 (Print) ISSN 1678-4375 (Online) THE INTERNATIONAL JOURNAL ON NEOTROPICAL BIOLOGY THE INTERNATIONAL JOURNAL ON GLOBAL BIODIVERSITY AND ENVIRONMENT Notes and Comments Asymmetry of the wing in Drosophila mojavensis sonorensis Castrezana in Pfeiler et al., 2009 (Diptera, Drosophilidae): main versus seasonal host J. O. Prestesa , M. Costab , L. P. B. Machadoa,b and R. P. Mateusa,b* aUniversidade Estadual do Centro-Oeste – UNICENTRO, Campus CEDETEG, Departamento de Ciências Biológicas, Programa de Pós-Graduação em Biologia Evolutiva, Guarapuava, PR, Brasil bUniversidade Estadual do Centro-Oeste – UNICENTRO, Campus CEDETEG, Departamento de Ciências Biológicas, Guarapuava, PR, Brasil Drosophila mojavensis sonorensis inhabits the Sonora (Palmer, 1994; Klingenberg and McIntyre, 1998; Palmer Desert and primarily uses cladodes of the columnar cactus and Strobeck, 2003). Procrustes distance between right Stenocereus thurberi (Engelm.) Buxb. as host (Pfeiler et al., and left wings of each individual was used as the level of 2009). However, when available, this subspecies also individual net asymmetry NAi (fluctuating + directional) uses decomposing fruits of cacti of the genus Opuntia (L.) and the global population asymmetry was estimated by Mill. (known as tunas) as seasonal hosts (Mateus et al., the average of the NAi in each population (Marchand et al., 2019). Therefore, the objective of this study was to test 2003). the stressing effect of two semi-natural diets, one from the The Procrustes ANOVA results showed that both primary host (S. thurberi cladodes) and another from the semi-natural diets caused instability in the development seasonal host (Opuntia spp. tunas), on the development (Table 1), mostly because of Las Bocas males (Mann-Whitney of D.
    [Show full text]
  • Functional Genomics of Cactus Host Shifts in Drosophila Mojavensis
    Molecular Ecology (2006) 15, 4635–4643 doi: 10.1111/j.1365-294X.2006.03102.x FBlackwell Publishing Ltnd ctional genomics of cactus host shifts in Drosophila mojavensis LUCIANO M. MATZKIN,* THOMAS D. WATTS, BENJAMIN G. BITLER, CARLOS A. MACHADO and THERESE A. MARKOW Department of Ecology and Evolutionary Biology, University of Arizona, PO Box 210088, Tucson, AZ 85721-0088, USA Abstract Understanding the genetic basis of adaptation to novel environments remains one of the major challenges confronting evolutionary biologists. While newly developed genomic approaches hold considerable promise for addressing this overall question, the relevant tools have not often been available in the most ecologically interesting organisms. Our study organism, Drosophila mojavensis, is a cactophilic Sonoran Desert endemic utilizing four different cactus hosts across its geographical range. Its well-known ecology makes it an attractive system in which to study the evolution of gene expression during adaptation. As a cactophile, D. mojavensis oviposits in the necrotic tissues of cacti, therefore exposing larvae and even adults to the varied and toxic compounds of rotting cacti. We have devel- oped a cDNA microarray of D. mojavensis to examine gene expression associated with cactus host use. Using a population from the Baja California population we examined gene expression differences of third instar larvae when reared in two chemically distinct cactus hosts, agria (Stenocereus gummosus, native host) vs. organpipe (Stenocereus thurberi, alternative host). We have observed differential gene expression associated with cactus host use in genes involved in metabolism and detoxification. Keywords: detoxification, Drosophila mojavensis, ecological genomics, Functional genomics, host shifts, microarray Received 19 April 2006; accepted 10 July 2006 interest is how natural selection shapes the transcriptional Introduction variation within a species.
    [Show full text]
  • A Conserved Activation Element in BMP Signaling During Drosophila Development
    ARTICLES A conserved activation element in BMP signaling during Drosophila development Alexander Weiss1, Enrica Charbonnier2,3, Elín Ellertsdóttir1, Aristotelis Tsirigos4, Christian Wolf 5,6, Reinhard Schuh5, George Pyrowolakis2,3 & Markus Affolter1 The transforming growth factor (TGF-) family member Decapentaplegic (Dpp) is a key regulator of patterning and growth in Drosophila development. Previous studies have identified a short DNA motif called the silencer element (SE), which recruits a trimeric Smad complex and the repressor Schnurri to downregulate target enhancers upon Dpp signaling. We have now isolated the minimal enhancer of the dad gene and discovered a short motif we termed the activating element (AE). The AE is similar to the SE and recruits the Smad proteins via a conserved mechanism. However, the AE and SE differ at important nucleotide positions. As a consequence, the AE does not recruit Schnurri but rather integrates repressive input by the default repressor Brinker and activating input by the Smad signal transducers Mothers against Dpp (Mad) and Medea via competitive DNA binding. The AE allows the identification of hitherto unknown direct Dpp targets and is functionally conserved in vertebrates. Members of the transforming growth factor β (TGF-β) and bone region of dad, which encodes the only Drosophila inhibitory Smad morphogenetic protein (BMP) ligand family are important for a Daughters against Dpp and is induced by Dpp signaling in most vast variety of biological processes1. These ligands signal through embryonic and larval tissues15–17. Here we report on the identifica- the structurally similar type I and type II serine-threonine kinase tion of the regulatory regions of dad and the characterization of a transmembrane receptors and the intracellular Smad proteins2,3.
    [Show full text]
  • Evolution of the Coeloconic Sensilla in the Peripheral Olfactory System of Drosophila Mojavensis
    Evolution of the coeloconic sensilla in the peripheral olfactory system of Drosophila mojavensis A thesis submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of Master of Science in the Department of Biological Sciences of the College of Arts and Sciences by Daniel Carl Nemeth B.S. in Zoology Miami University May 2015 Committee Chair: S. M. Rollmann, Ph.D. i ABSTRACT Distinct environmental conditions characterized by habitat, climate, resource availability, predation, and competition can result in the development of adaptive traits through natural selection. Divergence of adaptive traits can be seen in the olfactory systems of phytophagous insects with differing host plant preferences among conspecific populations. In this study, we examine the cactophilic fly, Drosophila mojavensis, which utilizes different host cacti across its range. Each cactus emits its own, unique composition of volatiles, which may serve as a primary sensory cue for host plant localization. Specifically, we study the olfactory system of these flies in attempts to elucidate mechanisms underlying the reported phenotypic divergence among populations. We observed variation in odor-evoked electrophysiological responses of acid and amine sensing olfactory sensory neurons (OSNs) of coeloconic sensilla across all sensillar types among populations. Additionally, we observed loss of expression an odorant receptor gene, Or35a in all four populations. Expansion to other Drosophila species revealed comparable absences in OSN responses to OR35a agonists in D. virilis and D. arizonae, suggesting a potential similar loss in gene expression as seen in D. mojavensis. Furthermore, responses of ac3 OSNs significantly differed to sixteen of the seventeen odorants tested across the four drosophilid species.
    [Show full text]
  • Phylogenetic Taxonomy in Drosophila Problems and Prospects
    [Fly 3:1, 10-14; January/February/March 2009]; ©2009 Landes Bioscience Drosophila taxonomy Review Phylogenetic taxonomy in Drosophila Problems and prospects Patrick M. O’Grady1,* and Therese A. Markow2 1University of California, Berkeley; Department of Environmental Science; Policy and Management; Berkeley, California USA; 2University of California, San Diego; Division of Biological Sciences; San Diego, California USA Key words: Drosophila, taxonomy, phylogenetics, evolution, classification The genus Drosophila is one of the best-studied model systems A given group of organisms can be classified as monophyletic, in modern biology, with twelve fully sequenced genomes available. paraphyletic or polyphyletic (Fig. 1A–C). Monophyletic groups, or In spite of the large number of genetic and genomic resources, clades, consist of a common ancestor and all descendants of that little is known concerning the phylogenetic relationships, ecology ancestor (Fig. 1A). Basing taxonomic structure on clades is a powerful and evolutionary history of all but a few species. Recent molecular approach because it provides information about the composition systematic studies have shown that this genus is comprised of at and exclusivity of a group. Shared derived characters that delimit a least three independent lineages and that several other genera are group can also be used to tentatively place newly discovered species. actually imbedded within Drosophila. This genus accounts for over Paraphyletic groups contain an ancestor and only some descendants 2,000 described, and many more undescribed, species. While some of that ancestor (Fig. 1B). Because some descendants of an ancestor Drosophila researchers are advocating dividing this genus into are not present in a paraphyletic group, these are less useful when three or more separate genera, others favor maintaining Drosophila trying to make an explicit statement about the evolutionary history as a single large genus.
    [Show full text]
  • Cryptolaemus Montrouzieri
    Li et al. BMC Genomics (2016) 17:281 DOI 10.1186/s12864-016-2611-8 RESEARCH ARTICLE Open Access Variation in life history traits and transcriptome associated with adaptation to diet shifts in the ladybird Cryptolaemus montrouzieri Hao-Sen Li1, Chang Pan1, Patrick De Clercq2, Adam Ślipiński3 and Hong Pang1* Abstract Background: Despite the broad diet range of many predatory ladybirds, the mechanisms involved in their adaptation to diet shifts are not completely understood. Here, we explored how a primarily coccidophagous ladybird Cryptolaemus montrouzieri adapts to feeding on aphids. Results: Based on the lower survival rate, longer developmental time, and lower adult body weight and reproduction rate of the predator, the aphid Megoura japonica proved being less suitable to support C. montrouzieri as compared with the citrus mealybug Planococcus citri. The results indicated up-regulation of genes related to ribosome and translation in fourth instars, which may be related to their suboptimal development. Also, several genes related to biochemical transport and metabolism, and detoxification were up-regulated as a result of adaptation to the changes in nutritional and non-nutritional (toxic) components of the prey. Conclusion: Our results indicated that C. montrouzieri succeeded in feeding on aphids by regulation of genes related to development, digestion and detoxification. Thus, we argue that these candidate genes are valuable for further studies of the functional evolution of ladybirds led by diet shifts. Keywords: Predacious ladybird, Cryptolaemus montrouzieri, Coccid, Aphid, Diet shift, Life history, Transcriptome Background have then switched back to feeding on coccids [1]. The predatory ladybirds (Coleoptera, Coccinellidae) Coccids and aphids have a quite different biochemical include many beneficial and economically significant composition and possess different secondary meta- species that are used as biological control agents against bolic products for self-protection [4], although they insect pests.
    [Show full text]
  • Behavioral and Environmental Contributions to Drosophilid Social Networks
    Behavioral and environmental contributions to drosophilid social networks Jacob A. Jezovita, Rebecca Rookea, Jonathan Schneidera, and Joel D. Levinea,1 aDepartment of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada Edited by Gene E. Robinson, University of Illinois at Urbana–Champaign, Urbana, IL, and approved April 1, 2020 (received for review November 25, 2019) Animals interact with each other in species-specific reproducible presence of predators and parasites (17). They engage in social patterns. These patterns of organization are captured by social learning (18–20) and display aggression (21). When a diseased network analysis, and social interaction networks (SINs) have been individual is present, group dynamics are altered (22). Taken to- described for a wide variety of species including fish, insects, birds, gether, these studies, among others, illustrate the biological value and mammals. The aim of this study is to understand the evolution of groups as well as a landscape of group dynamics among flies. of social organization in Drosophila. Using a comparative ecological, This social behavior displayed by Drosophila is amenable to phylogenetic, and behavioral approach, the different properties of social network analysis, which can be applied to better understand SINs formed by 20 drosophilids were compared. We investigate the importance of social interactions in a “solitary” insect. Pre- whether drosophilid network structures arise from common ances- viously, Schneider et al. (23) had shown that flies form social in- try, a response to the species’ past climate, other social behaviors, or teraction networks (SINs) and that associated metrics are strain a combination of these factors. This study shows that differences in dependent, indicating a genetic contribution to their structure.
    [Show full text]
  • Machado Et Al 2007.Pdf
    Molecular Ecology (2007) 16, 3009–3024 doi: 10.1111/j.1365-294X.2007.03325.x MBlackwell Publishingu Ltd ltilocus nuclear sequences reveal intra- and interspecific relationships among chromosomally polymorphic species of cactophilic Drosophila CARLOS A. MACHADO, LUCIANO M. MATZKIN, LAURA K. REED and THERESE A. MARKOW Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA Abstract Drosophila mojavensis and Drosophila arizonae, a pair of sibling species endemic to North America, constitute an important model system to study ecological genetics and the evolu- tion of reproductive isolation. This species pair can produce fertile hybrids in some crosses and are sympatric in a large part of their ranges. Despite the potential for hybridization in nature, however, evidence of introgression has not been rigorously sought. Further, the evolutionary relationships within and among the geographically distant populations of the two species have not been characterized in detail using high-resolution molecular studies. Both species have six chromosomes: five large acrocentrics and one ‘dot’ chromosome. Fixed inversion differences between the species exist in three chromosomes (X, 2 and 3) while three are colinear (4, 5 and 6), suggesting that were introgression to occur, it would be most likely in the colinear chromosomes. We utilized nucleotide sequence variation at multiple loci on five chromosomes to test for evidence of introgression, and to test various scenarios for the evolutionary relationships of these two species and their populations. While we do not find evidence of recent introgression, loci in the colinear chromosomes appear to have participated in exchange in the past. We also found considerable population structure within both species.
    [Show full text]