DOCSLIB.ORG

Bottlenecks and Blowflies Speciation, Reproduction and Morphological Variation in Lucilia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bottlenecks and Blowflies Speciation, Reproduction and Morphological Variation in Lucilia Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 660 _____________________________ _____________________________ Bottlenecks and Blowflies Speciation, Reproduction and Morphological Variation in Lucilia BY ANN-BRITT FLORIN ACTA UNIVERSITATIS UPSALIENSIS UPPSALA 2001 Dissertation for the Degree of Doctor of Philosophy in Animal Ecology presented at Uppsala University in 2001 Abstract Florin, A.-B. 2001. Bottlenecks and blowflies. Speciation, reproduction and morphological variation in Lucilia. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 660. 40 pp. Uppsala. ISBN 91- 554-5133-0. This thesis attempts to improve our understanding of the role of population size for the process of speciation. First, the effect of population size on speciation is studied using several meta-analyses of published laboratory experiments. Second, the effect of population size on behaviour is studied using a laboratory population of the blowfly Lucilia sericata. Third, the effect of population size on morphological and genetic variation is studied using wings and microsatellites from wild populations of L. illustris as well as experimentally bottlenecked populations of L. sericata. The meta-analyses showed that the result of many previous laboratory experiments on sympatric and parapatric speciation may have been biased by too small population sizes. Reduced interbreeding was less likely to develop in small populations where the selection against hybridisation often seemed to have been opposed by inbreeding depression or loss of genetic variation. In allopatric speciation experiments, no general consistent effect of population size was observed. There was no support for speciation through founder events. In fact, significant assortative mating was only found in vicariance experiments where derived populations was tested against each other. Population size influenced reproductive behaviour in L. sericata. There was a positive effect of increasing number of males on egg-laying but only as long as the female was in the company of at least one other female. Female mate choice and a positive effect of number of eggs on larval survival are suggested to be the underlying factors. No historic bottlenecks could be detected in the fly populations, but strong genetic indications suggest a fine grained genetic population structure of wild Lucilia flies. Bottlenecks had unpredictable effects on wing morphology as well as on genetic variation and fitness in a laboratory stock of L. sericata. Thus a bottlenecked population will not necessarily have a higher chance of evolving morphological novelties than one which has not undergone a bottleneck. However, among many bottlenecked populations there is a good chance that in at least one of them the conditions will be conducive to morphological change and evolution. In this statistical sense, thus, strong population fluctuations may enhance the probability of speciation events. Key words: Population size, speciation, Lucilia sericata, morphological variation, Lucilia illustris, bottlenecks. Ann-Britt Florin, Department of Animal Ecology, Evolutionary Biology Centre, Norbyv. 18D, SE-752 36 Uppsala, Sweden ([email protected]) © Ann-Britt Florin 2001 ISSN 1104-232X ISBN 91-554-5133-0 This thesis is based on the following papers, which will be referred to in the text by the roman numerals I-VI I Ödeen, A. & Florin, A.-B. 2000. Effective population size may limit the power of laboratory experiments to demonstrate sympatric and parapatric speciation. Proc. R. Soc. Lond. B. 267, 601-606. II Florin, A.-B. & Ödeen, A. Laboratory environments are not conducive for allopatric speciation. J. Evol. Biol. In press. III Florin, A.-B. Group size and composition affects reproduction in blowflies. Manuscript. IV Florin, A.-B. Morphological and genetic variation in wild populations of Lucilia illustris (Diptera: Calliphoridae). Manuscript. V Florin, A.-B. The effects of bottlenecks on morphological and genetic variation in Lucilia sericata (Diptera: Calliphoridae). Manuscript. VI Florin, A.-B. & Gyllenstrand, N. Isolation and characterization of polymorphic microsatellite markers in the blowflies Lucilia illustris and Lucilia sericata. Manuscript. Reprints were made by permission from the publisher. In paper I and II both authors contributed equally to the work. In paper VI the order of the authors reflects their involvement in the paper. Cover illustration and blowfly photo p. 7, copyright Mark C. Cassino. Contents INTRODUCTION 5 Speciation 5 The study species 7 GENERAL METHODS 9 Morphological data 9 Morphological integration 10 Genetic data 11 RESULTS AND DISCUSSION 12 Population size and sympatric and parapatric speciation 12 Population size and allopatric speciation 15 Population size and reproduction in blowflies 19 Genetic and morphological variation in wild L. illustris 21 Bottlenecks and morphological and genetic variation in L. sericata 24 CONCLUSIONS 28 ACKNOWLEDGEMENT 30 REFERENCES 30 SVENSK POPULÄRVETENSKAPLIG SAMMANFATTNING/ SWEDISH SUMMARY 38 4 INTRODUCTION Why are there so many species? This is a question that has been asked by mankind since the beginning of time. At the same time the preservation of form, morphologic stasis, is also apparent (Wake et al., 1983; Larson, 1989; Björklund, 1991, 1996; Benton & Pearson, 2001). Some traits differ greatly even in closely related species while other traits seem to stay unaltered through million of years (Gould & Eldredge, 1977; Turner, 1986). This paradox of stasis and yet a biological richness has led to the concepts of limiting adaptive gene complexes and founder effect which could break these complexes and allow for evolution of morphological novelties and even lead to speciation. Dobzhansky (1937) coined the term “coadaptation of the gene pool” meaning that the fitness of a gene is dependent on its genetic environment. Because genes are integrated, the adaptive value of a genotype is a property of the whole genome rather than of the constituent genes, and hence further evolution may require a thorough rebuilding of the genotype. Several lines of evidence suggest that such coadapted gene complexes exist (Cavener & Clegg, 1981; Carson & Templeton, 1984; Service & Rose, 1985; Stephan & Kirby, 1993; Clarke, 1997). Different models (peripatric speciation (Mayr, 1954); founder-flush speciation (Carson, 1975); accidental loss of male courtship behaviour (Kaneshiro, 1976); genetic transilience theory (Templeton, 1980); variance induced peak shifts (Whitlock, 1995)) offer alternative proposals how these complexes may break up and allow evolution to continue. Common for these models, however, are the stress on the stochastic effects of inbreeding and genetic drift associated with small population size. Speciation Mayr (1942) defines a species as a set of "groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups". I will use this Biological Species Concept throughout the thesis. Allopatric speciation, where new species arise from geographically isolated populations of the same ancestral species, is the most widely accepted of all current speciation models (Mayr, 1942, 1963; Lynch, 1989; Coyne, 1992; Rice & Hostert, 1993). It can be divided into vicariance and peripatric (or “peripheral isolates”) speciation (Lynch, 1989) depending on the location of the geographical split and the size of the sub- populations. In vicariance speciation (“the dumbbell model” in Mayr (1982)) a continuous population is split in the centre of its distribution, 5 giving rise to two or more large, isolated sub-populations. With time the sub-populations are thought to evolve reproductive isolation as a by- product of divergent selection pressures and/or genetic drift. In peripatric speciation (Mayr, 1954) (also commonly known as founder speciation) a small peripheral portion of the population becomes isolated and may undergo one or several (Carson, 1975) bottlenecks. Genetic drift caused by low population size during the bottlenecks together with relaxed selection pressure under the following flush phase, when the population rapidly increases in size, allows the formation of new gene combinations that would not have survived in the original population. Reproductive isolation is then believed to evolve either as a by-product of the genetic changes (Mayr, 1954; Carson, 1975; Templeton, 1980) or as a consequence of relaxation of mating preferences in bottlenecks (Kaneshiro, 1989). A more disputable model, although, recently more widely accepted (Via, 2001), is sympatric or parapatric speciation, that is, speciation without geographic isolation. Several hypotheses called “divergence-with-gene- flow speciation” (see Rice & Hostert, 1993) assume that populations become genetically isolated because traits for positive assortative mating coevolve with other traits under disruptive selection. Either selection against interbreeding is thought to build non-random associations between the genes responsible for the traits (linkage disequilibrium), or the traits represents different phenotypes deriving from the same gene (pleiotropy). The theory of “reinforcement” (Dobzhansky, 1940) implies that a feedback process between selection against hybrids and positive assortative mating reinforces reproductive isolation until the interbreeding populations have become genetically isolated. More theories of speciation are reviewed in
Load more

Recommended publications
  • New Host Plant Records for Species Of
    Life: The Excitement of Biology 4(4) 272 Geometric Morphometrics Sexual Dimorphism in Three Forensically- Important Species of Blow Fly (Diptera: Calliphoridae)1 José Antonio Nuñez-Rodríguez2 and Jonathan Liria3 Abstract: Forensic entomologists use adult and immature (larvae) insect specimens for estimating the minimum postmortem interval. Traditionally, this insect identification uses external morphology and/or molecular techniques. Additional tools like Geometric Morphometrics (GM) based on wing shape, could be used as a complement for traditional taxonomic species recognition. Recently, evolutionary studies have been focused on the phenotypic quantification for Sexual Shape Dimorphism (SShD). However, in forensically important species of blow flies, sexual variation studies are scarce. For this reason, GM was used to describe wing sexual dimorphism (size and shape) in three Calliphoridae species. Significant differences in wing size between females and males were found; the wing females were larger than those of males. The SShD variation occurs at the intersection between the radius R1 and wing margin, the intersection between the radius R2+3 and wing margin, the intersection between anal vein and CuA1, the intersection between media and radial-medial, and the intersection between the radius R4+5 and transversal radio-medial. Our study represents a contribution for SShD description in three blowfly species of forensic importance, and the morphometrics results corroborate the relevance for taxonomic purposes. We also suggest future investigations that correlated shape and size in sexual dimorphism with environmental factors such as substrate type, and laboratory/sylvatic populations, among others. Key Words: Geometric morphometric sexual dimorphism, wing, shape, size, Diptera, Calliphoridae, Chrysomyinae, Lucilinae Introduction In determinig the minimum postmortem interval (PMI), forensic entomologists use blowflies (Diptera: Calliphoridae) and other insects associated with body corposes (Bonacci et al.
    [Show full text]
  • Effect of Different Constant Temperature on the Life Cycle of A
    & Herpeto gy lo lo gy o : h C it u n r r r e O n , t y R g Entomology, Ornithology & e o l s Bansode et al., Entomol Ornithol Herpetol 2016, 5:3 o e a m r o c t h n E DOI: 10.4172/2161-0983.1000183 ISSN: 2161-0983 Herpetology: Current Research Research Article Open Access Effect of Different Constant Temperature on the Life Cycle of a Fly of Forensic Importance Lucilia cuprina Bansode SA1*, More VR1, and Zambare SP2 1Department of Zoology, Government College of Arts and Science, Aurangabad, Maharashtra, India 2Department of Zoology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, Maharashtra, India *Corresponding author: Bansode SA, Department of Zoology, Government College of Arts and Science, Aurangabad-431004, Maharashtra, India, Tel: 09665285290; E-mail: [email protected] Received date: July 08, 2016; Accepted date: July 29, 2016; Published date: August 02, 2016 Copyright: © 2016 Bansode SA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Lucilia cuprina is one of the forensically important Calliphoridae fly. L. cuprina is a helpful resource at the crime scenes as well as a nuisance to sheep. It is known to be one of the first flies to occupy a corpse upon its death. Due to this, it has great importance in forensic field to find out post-mortem interval. In this study, the development of L. cuprina is studied in an incubator at different constant temperatures.
    [Show full text]
  • Toleration of Lucilia Cuprina (Diptera: Calliphoridae) Eggs to Agitation Within Insect Saline
    Toleration of Lucilia cuprina (Diptera: Calliphoridae) Eggs to Agitation Within Insect Saline Christina Kaye Alvarez and Dr. Adrienne Brundage Editor: Colton Cooper Abstract: Microorganisms have an ability to attach themselves to surfaces, where they then multiply and form a protective biofilm, which protects the microorganisms from outside influences, including chemicals for sanitation. This makes the cleaning of fly eggs for maggot therapy difficult. The purpose of this study was to test the toleration of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) eggs for agitation, which is used to degrade biofilms. Lucilia cuprina eggs were washed with insect saline and treated by undergoing five minutes of agitation. It was found that there was a significant difference between the control group, which did not undergo any agitation, and the treatment group, which did. This knowledge is useful for further testing of the extent to which agitation impacts survivability of the eggs and the debridement of the biofilm. Keywords: Lucilia cuprina, maggot, debridement, biofilm Introduction side effects (Chai et al., 2014). This is no different for insect eggs, whose surfaces can Microorganisms have a propensity to be contaminated by various microorganisms attach themselves to surfaces, where they and for whom research is still ongoing to then multiply and often form a protective determine effective methods of surface biofilm (BF) (Chai et al., 2014). These sanitation, especially for use in maggot biofilms are made up of many different therapy. substances such as proteins, nucleic acids, mineral ions, and other debris from the cell Maggot therapy is the deliberate (Orgaz et al., 2006). Biofilms serve as treatment of wounds using fly larvae, and protective environments for bacteria under the species L.
    [Show full text]
  • Morphological Identification of Lucilia Sericata, Lucilia Cuprina and Their
    A peer-reviewed open-access journal ZooKeys 420:Morphological 69–85 (2014) identification of Lucilia sericata, Lucilia cuprina and their hybrids... 69 doi: 10.3897/zookeys.420.7645 RESEARCH ARTICLE www.zookeys.org Launched to accelerate biodiversity research Morphological identification of Lucilia sericata, Lucilia cuprina and their hybrids (Diptera, Calliphoridae) Kirstin A. Williams1, Martin H. Villet2 1 Entomology Department, Durban Natural Science Museum, Durban, South Africa 2 Southern African Forensic Entomology Research Laboratory, Department of Zoology and Entomology, Rhodes University, Gra- hamstown, 6140 South Africa Corresponding author: Kirstin A. Williams ([email protected]) Academic editor: P. Cerretti | Received 8 April 2014 | Accepted 9 June 2014 | Published 25 June 2014 http://zoobank.org/A13A1EBC-6A83-4001-BC62-387C978E86A1 Citation: Williams KA, Villet MH (2014) Morphological identification ofLucilia sericata, Lucilia cuprina and their hybrids (Diptera, Calliphoridae). ZooKeys 420: 69–85. doi: 10.3897/zookeys.420.7645 Abstract Hybrids of Lucilia sericata and Lucilia cuprina have been shown to exist in previous studies using molecu- lar methods, but no study has shown explicitly that these hybrids can be identified morphologically. Pub- lished morphological characters used to identify L. sericata and L. cuprina were reviewed, and then scored and tested using specimens of both species and known hybrids. Ordination by multi-dimensional scaling indicated that the species were separable, and that hybrids resembled L. cuprina, whatever their origin. Discriminant function analysis of the characters successfully separated the specimens into three unam- biguous groups – L. sericata, L. cuprina and hybrids. The hybrids were morphologically similar irrespective of whether they were from an ancient introgressed lineage or more modern.
    [Show full text]
  • Cutaneous Myiasis: Is Lucilia Cuprina Safe and Acceptable for Maggot Debridement Therapy?
    Journal of Cosmetics, Dermatological Sciences and Applications, 2012, 2, 79-82 79 http://dx.doi.org/10.4236/jcdsa.2012.22018 Published Online June 2012 (http://www.SciRP.org/journal/jcdsa) Cutaneous Myiasis: Is Lucilia cuprina Safe and Acceptable for Maggot Debridement Therapy? Howard Joesphia Kingu1, Simon Kamande Kuria2*, Martin Herrer Villet3, Jane Nthekeleng Mkhize2, Adupa Dhaffala1, John Michael Iisa2 1Department of Surgery, Walter Sisulu University, Mthatha, South Africa; 2Department of Biological Sciences, Walter Sisulu University, Mthatha, South Africa; 3Department of Entomology and Zoology, Rhodes University, Grahamstown, South Africa. Email: *[email protected] Received February 8th, 2012; revised March 17th, 2012; accepted April 2nd, 2012 ABSTRACT Preservation of viable tissue is important in wound management. It is achieved by small, incremental removal of de- vitalised, necrotic and infected tissues. Maggot debridement therapy (MDT) is used in septic necrotic wounds that fail to respond to conventional modalities. MDT has relied on Lucilia sericata, which consumes only necrotic tissues, as opposed to Lucilia cuprina, which devours both flesh and necrotic tissues. Recent findings have shown that L. cuprina consumes mainly necrotic and very small amounts of viable tissues and may be used in MDT where L. sericata is very rare or absent. Here we describe wound healing in a patient from rural South Africa with cutaneous myiasis. Our find- ings agree with workers who indicated that L. cuprina could be used in MDT. Keywords: Maggots; Blow Flies; Lucilia cuprina; Mthatha 1. Introduction dorsum of his right foot by a fencing wire. No pain or discomfort followed the injury. However, four days prior Invasion of mammalian tissues or organs by dipteran to presentation he noted that his foot had started to swell larvae (maggots) is referred to as myiasis [1].
    [Show full text]
  • Sheep Blowfly Biology
    Sheep blowfly biology The Australian sheep blowfly, Lucilia cuprina, is responsible for initiating over 90% of sheep flystrikes in Australia. It preferentially, but not exclusively, breeds on sheep. Several other blowfly species are sometimes involved in flystrike but each of these breeds mainly in carrion. The L. cuprina life-cycle (figure 1) is intimately linked with sheep. Variation in strike incidence relates mainly to the occurrence of susceptible sheep, not the density of sheep blowflies in the area. Trap catches of as few as 1-2 flies / hour, or estimated densities of 7-10 blowflies / hectare are enough to cause extensive strike if susceptible sheep are present. Sheep blowflies cannot lay eggs until they have consumed a protein meal. They then mate and the female flies develop eggs. Depending on the size of the female, batches of up to 200 eggs can be laid per ovarian cycle. Sheep blowflies can live for over a month in the field. During this time three batches of eggs may be laid. L. cuprina eggs are not laid indiscriminately. Female flies seek out susceptible sheep. Putrefactive odours and odours associated with fleece rot bacteria or dermatophilosis are particularly attractive. Initially females are attracted by smell. Later visual cues are used. When a susceptible sheep is found, the preferred oviposition site is located using taste receptors on the tarses (feet), mouthparts and finally the ovipositor (genitalia). The eggs are susceptible to desiccation, but there is safety in numbers. Ovipositing females produce a contact pheromone to entice other females to lay at the same site. Susceptible sheep may have very large egg masses laid on them by dozens of flies.
    [Show full text]
  • Wound Myiasis Caused by Lucilia Sericata
    Arch Iranian Med 2004; 7 (2): 128 – 129 Case Report WOUND MYIASIS CAUSED BY LUCILIA SERICATA Safar-Ali Talari PhD·, Fakhrodin Sadr MD, Abbas Doroodgar MSc, Mohammad-Reza Talari MSc, Ali-Shoja Gharabagh MSc Lucilia sericata is one of the facultative parasites which causes myiasis in animals, and rarely in humans as an ectoparasite. Infestation in humans and domestic herbivorous animals occurs in wounds, mouth, eyes, and nose. It causes itching, pain, inflammation, secondary bacterial infections, eosinophilia, and erythema. We report on a 26-year-old man from Kashan, with a 12- year history of opium and a 3-year history of heroin injections was taken to Iran, following a heroine injection, and with signs of hypoxic encephalopathy, decreasing mental clearness, and coma. He was HBsAg and HIV negative, and HCV positive. From the wounds of his left hand, which were caused by repeated injections, 38 live larvae were removed. The larvae proved to be Lucilia sericata. Archives of Iranian Medicine, Volume 7, Number 2, 2004: 128 – 129. Keywords · Kashan · Lucilia sericata · myiasis Introduction complete peritreme of posterior respiratory spiracles. After 4 – 8 days, larvae develop and drop ucilia sericata and Lucilia cuprina flies onto soil and after 6 to 14 days transform into adult belong to Calliphoridae family which are fly. Lucilia larva very rarely invades living tissues L ectoparasites found in meat and corpse of and feeds. Larva has two posterior breathing animals, and cause myiasis in humans and spiracles can be seen. The third stage larva, after 1 – 3 leaving nutritious wounds continues to develop in domestic herbivorous animals.
    [Show full text]
  • Terry Whitworth 3707 96Th ST E, Tacoma, WA 98446
    Terry Whitworth 3707 96th ST E, Tacoma, WA 98446 Washington State University E-mail: [email protected] or [email protected] Published in Proceedings of the Entomological Society of Washington Vol. 108 (3), 2006, pp 689–725 Websites blowflies.net and birdblowfly.com KEYS TO THE GENERA AND SPECIES OF BLOW FLIES (DIPTERA: CALLIPHORIDAE) OF AMERICA, NORTH OF MEXICO UPDATES AND EDITS AS OF SPRING 2017 Table of Contents Abstract .......................................................................................................................... 3 Introduction .................................................................................................................... 3 Materials and Methods ................................................................................................... 5 Separating families ....................................................................................................... 10 Key to subfamilies and genera of Calliphoridae ........................................................... 13 See Table 1 for page number for each species Table 1. Species in order they are discussed and comparison of names used in the current paper with names used by Hall (1948). Whitworth (2006) Hall (1948) Page Number Calliphorinae (18 species) .......................................................................................... 16 Bellardia bayeri Onesia townsendi ................................................... 18 Bellardia vulgaris Onesia bisetosa .....................................................
    [Show full text]
  • Molecular Analysis of Forensically Important Blow Flies in Thailand
    insects Article Molecular Analysis of Forensically Important Blow Flies in Thailand Narin Sontigun 1, Kabkaew L. Sukontason 1, Jens Amendt 2, Barbara K. Zajac 3, Richard Zehner 2, Kom Sukontason 1, Theeraphap Chareonviriyaphap 4 and Anchalee Wannasan 1,* 1 Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; [email protected] (N.S.); [email protected] (K.L.S.); [email protected] (K.S.) 2 Institute of Legal Medicine, Forensic Biology/Entomology, Kennedyallee 104, Frankfurt am Main 60596, Germany; [email protected] (J.A.); [email protected] (R.Z.) 3 Department for Forensic Genetics, Institute of Forensic Medicine and Traffic Medicine, Voßstraße 2, Heidelberg 69115, Germany; [email protected] 4 Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand; [email protected] * Correspondence: [email protected]; Tel.: +66-8-9434-6851 Received: 13 September 2018; Accepted: 6 November 2018; Published: 8 November 2018 Abstract: Blow flies are the first insect group to colonize on a dead body and thus correct species identification is a crucial step in forensic investigations for estimating the minimum postmortem interval, as developmental times are species-specific. Due to the difficulty of traditional morphology-based identification such as the morphological similarity of closely related species and uncovered taxonomic keys for all developmental stages, DNA-based identification has been increasing in interest, especially
    [Show full text]
  • A Review of Sheep Blowfly Pathogen Control
    Project No: ON-00620 Contract No: PO4500012271 AWI Project Manager: Bridget Peachey Contractor Name: AgResearch Prepared by: David Wright, Mark Hurst & Dave Leathwick Publication Date: August 2019 A Review of Sheep Blowfly Pathogen Control Published by Australian Wool Innovation Limited, Level 6, 68 Harrington Street, THE ROCKS, NSW, 2000 This publication should only be used as a general aid and is not a substitute for specific advice. To the extent permitted by law, we exclude all liability for loss or damage arising from the use of the information in this publication. © 2019 Australian Wool Innovation Limited. All rights reserved. AWI invests in research, development, innovation and marketing activities along the global supply chain for Australian wool. AWI is grateful for its funding, which is primarily provided by Australian woolgrowers through a wool levy and by the Australian Government which provides a matching contribution for eligible R&D activities. Contents 1. Introduction ............................................................................................................................................ 3 1.1 Sheep strike ......................................................................................................................................... 3 1.2 Biopesticides ....................................................................................................................................... 4 1.3 Initial investigations of biocontrol .....................................................................................................
    [Show full text]
  • Forensic Entomology: the Use of Insects in the Investigation of Homicide and Untimely Death Q
    If you have issues viewing or accessing this file contact us at NCJRS.gov. Winter 1989 41 Forensic Entomology: The Use of Insects in the Investigation of Homicide and Untimely Death by Wayne D. Lord, Ph.D. and William C. Rodriguez, Ill, Ph.D. reportedly been living in and frequenting the area for several Editor’s Note weeks. The young lady had been reported missing by her brother approximately four days prior to discovery of her Special Agent Lord is body. currently assigned to the An investigation conducted by federal, state and local Hartford, Connecticut Resident authorities revealed that she had last been seen alive on the Agency ofthe FBi’s New Haven morning of May 31, 1984, in the company of a 30-year-old Division. A graduate of the army sergeant, who became the primary suspect. While Univercities of Delaware and considerable circumstantial evidence supported the evidence New Hampshin?, Mr Lordhas that the victim had been murdered by the sergeant, an degrees in biology, earned accurate estimation of the victim’s time of death was crucial entomology and zoology. He to establishing a link between the suspect and the victim formerly served in the United at the time of her demise. States Air Force at the Walter Several estimates of postmortem interval were offered by Army Medical Center in Reed medical examiners and investigators. These estimates, Washington, D.C., and tire F however, were based largely on the physical appearance of Edward Hebert School of the body and the extent to which decompositional changes Medicine, Bethesda, Maryland. had occurred in various organs, and were not based on any Rodriguez currently Dr.
    [Show full text]
  • Systems in the Australian Sheep Blowfly Lucilia Cuprina
    HeredityG7 (1991) 365—371 Received 2 February 7991 OThe Genetical Society of Great Britain Male crossing over and genetic sexing systems in the Australian sheep blowfly Lucilia cuprina GEOFFREY G. FOSTER, GAVE L. WELLER & GEOFFREY M. CLARKE CSIRO Division of Entomology. GPO Box 1700, Canberra ACT 2601, Australia Field-femalekilling (FK) systems based on deleterious mutations arid Y-autosome translocations are being evaluated for genetic control of the Australian sheep blowfly, Lad/ia cuprina. Experience during field trials has shown that mass-reared colonies of FK strains are subject to genetic deterioration, caused mainly by genetic recombination in males. A previous study found higher male recombination frequencies in two Y-linked translocation strains than in chromosomally normal males. However, the results of the present study indicate that breakage of the Y chromosome is neither sufficient nor necessary for increased levels of male recombination. The fre- quency of male recombination appears to be unrelated to the presence of specific chromosome rearrangements. Keywords:genetic control,genetic sexing, Lad/ia cuprina, male recombination. FTC-strain females are homozygous for one or more Introduction eye-pigment mutations and have white eyes. They can Geneticsexing systems facilitate separation or killing of survive in cages, but they are functionally blind, rarely mass-reared insects according to sex. This is most surviving long in the field; in other words the eye- frequently accomplished by artificially linking appro- colour mutations are recessive lethals under field con- priate mutations with sex using rearrangements ditions (Whitten ci at, 1977). between sex-determining chromosomes and other FK-strain males carry the eye-colour mutations on a chromosomes, although other sex-determining mech- single set of normal autosomes, and the wild-type anisms can be exploited (reviewed by Whitten & Foster, alleles on the translocation.
    [Show full text]