DOCSLIB.ORG

Genetic Control of Male Germ Unit Organization in Arabidopsis1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Genetic Control of Male Germ Unit Organization in Arabidopsis1 Genetic Control of Male Germ Unit Organization in Arabidopsis1 Eric Lalanne and David Twell* Department of Biology, University of Leicester, Leicester LE1 7RH United Kingdom In flowering plants, the vegetative nucleus and the two sperm cells are proposed to form a functional assemblage, the male germ unit (MGU). Here, we describe the developmental pathway of MGU assembly in Arabidopsis and report two classes of mutations that affect the integrity and/or the positioning of the MGU in the mature pollen grain. In germ unit malformed (gum) mutants, the vegetative nucleus is positioned adjacent to the pollen grain wall, separate from the two sperm cells, whereas in MGU displaced (mud) mutants, the intact MGU is displaced to the pollen grain wall. mud and gum mutants correspond to male-specific gametophytic mutations that also reduce pollen fitness. Genetic mapping showed that the gum1 and gum2 mutations are genetically linked, possibly allelic, whereas the mud1 and mud2 mutations correspond to two unlinked loci mapping on different chromosomes. The hierarchical relationship between mud and gum mutations was investigated by phenotypic analysis of double mutants. gum1 appeared to act earlier than mud1 and mud2, affecting initial MGU assembly and its stability during pollen maturation. In contrast, mud1 and mud2 mutations appear to act only on MGU positioning during final maturation. From in planta analyses of pollen germination in mud and gum mutants, we conclude that the initial proximity and positioning of MGU components is not required for their entrance into the pollen tube, but the efficiency of MGU translocation is reduced. Flowering plants produce mature dehydrated pol- fertilization has been observed in at least two species len grains competent for rapid germination and pol- (Roman, 1947, 1948; Russell, 1985). len tube growth. In 70% of species, the mature pollen Since its conception, the MGU aroused renewed grain contains a small generative cell that is com- interest in pollen organization and fertilization, and pletely enclosed within a large vegetative cell (bicel- stimulated a number of descriptive studies leading to lular pollen species). After germination, the genera- the ultrastructural characterization and computer- tive cell undergoes a mitotic division to form the two assisted reconstruction of the MGU (for review, see sperm cells necessary for double fertilization. In tri- Mogensen, 1992). In the MGU, one sperm cell is cellular pollen species, the generative cell undergoes connected to the vegetative nucleus via a “tail,” or the second mitotic division prior to anthesis. In the cell extension, containing forked arrays of microtu- majority of tricellular pollen species that have been bules. This tail penetrates the highly convoluted veg- examined, the two compact, but elongated, sperm etative nucleus (McConchie et al., 1985), whereas the cells are in direct physical association with and par- two sperm cells are enclosed within a vegetative cell tially surrounded by the vegetative cell nucleus (for membrane-bound compartment, and are linked by a review, see Mogensen, 1992; Dumas et al., 1998). The transverse cell wall and evaginations of their plasma associated vegetative nucleus and sperm cells are membranes (Dumas et al., 1984a, 1984b; Charzinska proposed to form a functional assemblage, termed et al., 1989). In mature bicellular pollen systems, and the male germ unit (MGU), with a potential role in in tricellular pollen of monocotyledonous species the controlled transport and delivery of the sperm such as maize (Zea mays), the MGU is not observed in cells (Dumas et al., 1984a). Moreover, the sperm cell mature pollen, but assembly occurs early during pol- dimorphism observed in several species suggests len tube growth (Hu and Yu, 1988; Rougier et al., that the MGU is a “polarized fertilization unit” in 1991). Despite these apparent differences in the tim- which the sperm cells are predetermined to fuse with ing of MGU assembly, the existence of MGUs in the egg nucleus or the two polar nuclei. Preferential angiosperm pollen and their presumptive impor- tance in double fertilization are now largely accepted 1 E.L. was funded by a Marie Curie Research Fellowship (no. (for review, see Dumas et al., 1998). ERBFMBICT972310) under the European Economic Community To date, MGU assembly has only been described Training and Mobility of Researchers program. The initial screen- during pollen germination and tube growth in bicel- ing work was funded by the Biotechnology and Biological Science lular pollen species (Hu and Yu, 1988; Rougier et al., Research Council (research grant no. CAD04305 to D.T.) under the 1991). The ontogeny of MGU assembly in tricellular Cell Commitment and Determination Initiative. * Corresponding author; e-mail [email protected]; fax 44–116–252– pollen species remains largely unknown. In particu- 2791. lar, it is not known whether associations between the Article, publication date, and citation information can be found three components exist early during bicellular devel- at www.plantphysiol.org/cgi/doi/10.1104/pp.003301. opment, from the time of sperm formation, or Plant Physiology, June 2002, Vol. 129,Downloaded pp. 865–875, from www.plantphysiol.org on May 5, 2019 - Published © 2002 by American www.plantphysiol.org Society of Plant Biologists 865 Copyright © 2002 American Society of Plant Biologists. All rights reserved. Lalanne and Twell whether the associations are established later. More- ture pollen grains were viable in gum and mud over, the molecular and genetic basis of MGU assem- homozygotes (Ͼ400 spores scored for each mutants). bly and positioning are still unknown. Furthermore, no obvious aberrant sporophytic phe- Mutational analysis is proving to be an effective notypes were observed in homozygous mutants, sug- approach for identifying gametophytic genes in- gesting that these mutations act specifically in the volved in regulating cell division, polarity, and cell male gametophyte to affect MGU organization. fate during pollen development and function (Chen and McCormick, 1996; Feldmann et al., 1997; MGU Organization in Wild-Type, gum, and mud Pollen Hulskamp et al., 1997; Bonhomme et al., 1998; How- den et al., 1998; Park et al., 1998; Grini et al., 1999; The mud1 and mud2 mutants showed a similar and Johnson and McCormick, 2001; Procissi et al., 2001). striking pollen phenotype in that the associated Given the stereotypical organization and central lo- sperm cells and vegetative nucleus were strongly cation of the MGU in mature Arabidopsis pollen displaced to periphery of the pollen grain as a single grains, we used the MGU as a structural marker in a associated unit (Fig. 1, c, f, and i). The gum1 and gum2 screen to identify genes controlling MGU assembly mutants also showed a striking but distinct pollen and/or intracellular architecture. Here, we describe phenotype wherein the vegetative nucleus was posi- the process of MGU assembly during pollen devel- tioned against the pollen grain wall and was clearly opment in Arabidopsis. We describe the identifica- separated from the sperm cell pair (Fig. 1, b and h). tion and characterization of two distinct classes of Optical sectioning of DAPI-stained pollen of gum1/ pollen mutants, germ unit malformed (gum) and gum1 plants by CLSM confirmed that the vegetative MGU displaced (mud), that act gametophytically to nucleus was always strongly displaced, adjacent to affect the assembly and positioning of the MGU, the pollen wall, whereas the sperm cells were located respectively. We provide cytological and genetic ev- centrally or in the cortical cytoplasm (Fig. 1h). De- idence that demonstrates genetic control of MGU spite their separation, the vegetative nucleus and the assembly and positioning, and we suggest that cor- sperm cells were still sometimes observed to be phys- rect MGU organization is required for efficient trans- ically associated via a long extension of the vegeta- mission of the male gametes through pollen. tive nucleus (Fig. 1e). CLSM analysis of homozygous mud1/mud1 and mud2/mud2 pollen confirmed that the intact MGU was always strongly displaced to the RESULTS pollen wall (Fig. 1i). The MGU in both mud mutants Isolation of mud and gum Mutants characteristically showed a more compact structure than the wild type, with the sperm cells tightly asso- In mature Arabidopsis pollen grains, the vegetative ciated with each other and with the vegetative nucleus and associated sperm cell pair (MGU) oc- nucleus. cupy a central position in the vegetative cell cyto- We investigated whether there was any preferen- plasm (Owen and Makaroff, 1995). Therefore, muta- tial positioning of MGU components relative to the tions affecting pollen intracellular architecture polar axis of the pollen grain (Park et al., 1998). should disrupt this stereotypical organization. Ma- Pollen grains were observed perpendicular to their ture 4,6-diamidino-2-phenylindole (DAPI)-stained polar axes and were divided into three transverse pollen from approximately 10,000 M2 individuals segments from the pole to the equator for scoring. No from an ethylmethane sulfonate (EMS)-mutagenized preferential association of MGU components with Arabidopsis population were screened by epifluores- polar, intermediate, or equatorial segments was ob- cence microscopy. Two classes of mutants affecting served in homozygous gum and mud mutants (ap- the MGU were identified, two individuals termed proximately 400 spores scored for each mutant). gum gum and two individuals termed mud, all
Load more

Recommended publications
  • Cyber-Synchronicity: the Concurrence of the Virtual
    Cyber-Synchronicity: The Concurrence of the Virtual and the Material via Text-Based Virtual Reality A dissertation presented to the faculty of the Scripps College of Communication of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Jeffrey S. Smith March 2010 © 2010 Jeffrey S. Smith. All Rights Reserved. This dissertation titled Cyber-Synchronicity: The Concurrence of the Virtual and the Material Via Text-Based Virtual Reality by JEFFREY S. SMITH has been approved for the School of Media Arts and Studies and the Scripps College of Communication by Joseph W. Slade III Professor of Media Arts and Studies Gregory J. Shepherd Dean, Scripps College of Communication ii ABSTRACT SMITH, JEFFREY S., Ph.D., March 2010, Mass Communication Cyber-Synchronicity: The Concurrence of the Virtual and the Material Via Text-Based Virtual Reality (384 pp.) Director of Dissertation: Joseph W. Slade III This dissertation investigates the experiences of participants in a text-based virtual reality known as a Multi-User Domain, or MUD. Through in-depth electronic interviews, staff members and players of Aurealan Realms MUD were queried regarding the impact of their participation in the MUD on their perceived sense of self, community, and culture. Second, the interviews were subjected to a qualitative thematic analysis through which the nature of the participant’s phenomenological lived experience is explored with a specific eye toward any significant over or interconnection between each participant’s virtual and material experiences. An extended analysis of the experiences of respondents, combined with supporting material from other academic investigators, provides a map with which to chart the synchronous and synonymous relationship between a participant’s perceived sense of material identity, community, and culture, and her perceived sense of virtual identity, community, and culture.
    [Show full text]
  • Austin Games Conference 2005
    Why are we here? 28 th october 2005 Austin games conference profesSor Richard A. Bartle University of esSEx introduction • It is a truth universally acknowledged… • that I’ve called this talk “why are we here?” – I include as “we” those who would have been here if they hadn’t been out ”Networking” until 2:30am this morning • I do mean the question quite literally: why are any of us in this location right now ? • This is actually a meaningful question… 1 Deep and meaningful Put another way • Point of fact: you are All goinG to DIE • Given this information, why are you here ? In this converted balLroOm ? • Why aren’t you in – paris? – China? – Darfur? – Bed? – World of warcraft ? • Hmm, I guess some of you are in there… 2 Short answer • Well, you’re here because you’re mMorpg developers and this is a mmorpg developers’ conference – officially, “networked game development” conference… • [aside: I’m gonna call them virtual worlds , not mMorpgs ] – I’m not giving up on my book’s title yet , dammit! • But this leads to another question: Another question • Why are you [mmorpg] virtual world developers? • Why aren’t you – regular game developers? – Novelists? – Truck drivers? – Nuclear power station software engineers? – Lawyers? – level 80 on runescape with 2 blue masks, 2 green masks, 2 santa hats and a red party hat ? • “Because it would cost me $5,100 on ebay” (44 bids, 13 hours to go, and simbatamer realLy wants it) 3 hackers • Notice the subtitle answers • Some posSible answers: – You’re a vw developer Purely by acCident – You wanted a
    [Show full text]
  • Download the Pdf
    Why? are all that play games. Immature is the people, someone is going to commit same as youth. Young! Our young boys suicide.” Because it’s out there. We should talk are being exposed to age-inappropriate Hello fellow Escapists, I have some about it. If we don’t talk about it, it’s material! Indeed, The Escapist picks out this exciting news. Our clan just grew one more likely to go places that’s not observation as worthy of highlighting in larger. Russ Pitts, previously of Gamers healthy. If we try to sweep it under the Can you blame them? I sure can’t. What a larger font alongside the article. But with Jobs, has joined our editorial team bed, it will be hidden in the darkest, needs to happen, before games can did he really mean this? as Associate Editor for Acquisitions. dirtiest crevices of the internet that are comfortably be seen as accepted We’re all pretty excited to have him, and not always safe. So, let’s bring it out in entertainment for people over the age of It seems rather more likely that this is look forward to incorporating his ideas the open – we’re all adults here. 18, is not just that developers need to two observations combined. 20% is one into The Escapist. Everyone please make games appealing to adults (which “out of five people” in the country. And: welcome Russ! What? Adults play games? They’re not many are), but the media needs to with a sample that large “someone is just child’s toys? Yes, that is correct.
    [Show full text]
  • The New Third Place: Massively Multiplayer Online Gaming in American Youth Culture
    Tidskrift för lärarutbildning och forskning Nr 3/2005 Årgång 12 FAKULTETSNÄMNDEN FÖR LÄRARUTBILDNING THE FACULTY BOARD FOR TEACHER EDUCATION Tidskrift för lärarutbildning och forskning nr 3 2005 årgång 12 Tidskrift för lärarutbildning och forskning (fd Lärarutbildning och forskning i Umeå) ges ut av Fakultetsnämnden för lärarutbildning vid Umeå universitet. Syftet med tidskriften är att skapa ett forum för lärarutbildare och andra didaktiskt intresserade, att ge information och bidra till debatt om frågor som gäller lärarutbildning och forskning. I detta avseende är tidskriften att betrakta som en direkt fortsättning på tidskriften Lärarutbildning och forskning i Umeå. Tidskriften välkomnar även manuskript från personer utanför Umeå universitet. Tidskrift för lärarutbildning och forskning beräknas utkomma med fyra nummer per år. Ansvarig utgivare: Dekanus Björn Åstrand Redaktör: Fil.dr Gun-Marie Frånberg, 090/786 62 05, e-post: [email protected] Bildredaktör: Doktorand Eva Skåreus e-post: [email protected] Redaktionskommitté: Docent Håkan Andersson, Pedagogiska institutionen Professor Åsa Bergenheim, Pedagogiskt arbete Docent Per-Olof Erixon, Institutionen för estetiska ämnen Professor Johan Lithner, Matematiska institutionen Doktorand Eva Skåreus, Institutionen för estetiska ämnen Universitetsadjunkt Ingela Valfridsson, Institutionen för moderna språk Professor Gaby Weiner, Pedagogiskt arbete Redaktionens adress: Tidskrift för lärarutbildning och forskning, Gun-Marie Frånberg, Värdegrundscentrum, Umeå universitet, 901 87 UMEÅ. Grafisk formgivning: Eva Skåreus och Tomas Sigurdsson, Institutionen för estetiska ämnen Illustratör: Eva Skåreus Original: Print & Media, Umeå universitet Tryckeri: Danagårds grafiska, 2005:2001107 Tekniska upplysningar till författarna: Tidskrift för lärarutbildning och forskning framställs och redigeras ur allmänt förekommande Mac- och PC-program. Sänd in manuskript på diskett eller som e-postbilaga.
    [Show full text]
  • UCLA Electronic Theses and Dissertations
    UCLA UCLA Electronic Theses and Dissertations Title Transcoded Identities: Identification in Games and Play Permalink https://escholarship.org/uc/item/0394m0xb Author Juliano, Linzi Publication Date 2015 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA Los Angeles Transcoded Identities: Identification in Games and Play A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Theater and Performance Studies By Linzi Michel Juliano 2015 © Copyright by Linzi Michel Juliano 2015 ABSTRACT OF THE DISSERTATION Transcoded Identities: Identification in Games and Play By Linzi Michel Juliano Doctor of Philosophy in Theater and Performance Studies University of California, Los Angeles, 2015 Professor Sue-Ellen Case, Chair This work foregrounds how technologies create and emerge from sociocultural, economic and political discourses. My use of transcode, a term introduced by the semiotician A.J. Greimas and carried into the digital realm by Lev Manovich, refers to how cultural elements such as assumptions, biases, priorities emerge within programming code and software. It demonstrates how cultural norms persist across different mediums and posits that, in many ways, the capacity to be flexible defines cultural ideologies. At the software level, programming languages work like performative speech: grammar which produces effects. When cast as speech, coming from a body (or bodies) instead of hardware, information structures can be perceived as acting within regimes of corporeality; when cast as software, information structures demonstrate and advertise the capabilities of hardware. Although often aligned with veracity and stability in its proximity to (computer) science, software is not culturally neutral.
    [Show full text]
  • GENDER SWAPPING on the INTERNET Amy S. Bruckman Presented at the Internet Society, San Fransisco, CA, August 1993
    GENDER SWAPPING ON THE INTERNET Amy S. Bruckman Presented at The Internet Society, San Fransisco, CA, August 1993. ABSTRACT In text-based virtual reality environments on the Internet called MUDs, it is possible to pretend to be the opposite gender. In these virtual worlds, the way gender structures basic human interaction is often noticed and reflected upon. This paper introduces MUDs, and then presents a community discussion about gender issues that MUDs inspired. Gender swapping is one example of ways in which network technology can impact not just work practice but also culture and values. I. GENDER SWAPPING ON THE INTERNET On the television show Saturday Night Live, a series of skits concerned a character named Pat, who has no apparent gender. The audience is tempted with the promise of clues. In one episode, Pat gets his or her hair cut. A sign in the salon says that men's haircuts are $7, and women's haircuts are $9. The audience waits in suspense: when Pat goes to pay, his or her true gender will be revealed. The humor of the series lies in the fact that those hopes are constantly foiled; in this instance, Pat leaves $10 and says to keep the change. Gender is so fundamental to human interactions, that the idea of a person without gender is absurd. The audience thinks that surely some clue must reveal Pat's gender, but none ever does. Many who have never seen Saturday Night Live know about Pat.(2) The character has become a kind of cultural icon. Pat's popularity is revealing.
    [Show full text]
  • Telecommunications Seminar 2007
    Why peoPlE play MmorPgs Indiana University 11 th April 2007 Prof. Richard A. Bartle University of esSex introduction • This talk concerns massively multiplayer online role-playing games – Mmorpgs to the players • Or mmogs, mmos, pws, muds, mugs, mu*s, … – Virtual worlds to academics • Or synthetic worlds, virtual environments, … • My aim here is to explain Why people play them – Because, hey, then we get better ones! • Get comfy, it’s a long journey… 1 What are vws? • Virtual worlds are places • being places, they have a number of place- like features – You can visit them – Other people can also visit them – At the same time • They are, however, not real • This seems like a major disadvantage – How do you visit somewhere that isn’t real? Answer: • You use an avatar – Or, more technically speaking, a character 2 About avatars • Far from its being a disadvantage , people often like using an avatar Furthermore… • Some people prefer it to reality 3 Leisure time • People play these for several hours a day – Day after day • Month after month – Year after year… • I have players for my own game that are still there after 19 years • Surveys have consistently shown that The average time a player spends in a virtual world is around 20 hours a wEek – They often invest a lot of time in it oFfline , too • So where did these games come from? World of warcraft • world of warcraft , blizzard, 2004: 4 everquest • Everquest , sony online entertainment, 1999 connection • Everquest ruled until Wow came along – 480,000 subscriptions at its peak • Wow is modeLled
    [Show full text]
  • Mud Connector
    Archive-name: mudlist.doc /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ /_/_/_/_/ THE /_/_/_/_/ /_/_/ MUD CONNECTOR /_/_/ /_/_/_/_/ MUD LIST /_/_/_/_/ /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ o=======================================================================o The Mud Connector is (c) copyright (1994 - 96) by Andrew Cowan, an associate of GlobalMedia Design Inc. This mudlist may be reprinted as long as 1) it appears in its entirety, you may not strip out bits and pieces 2) the entire header appears with the list intact. Many thanks go out to the mud administrators who helped to make this list possible, without them there is little chance this list would exist! o=======================================================================o This list is presented strictly in alphabetical order. Each mud listing contains: The mud name, The code base used, the telnet address of the mud (unless circumstances prevent this), the homepage url (if a homepage exists) and a description submitted by a member of the mud's administration or a person approved to make the submission. All listings derived from the Mud Connector WWW site http://www.mudconnect.com/ You can contact the Mud Connector staff at [email protected]. [NOTE: This list was computer-generated, Please report bugs/typos] o=======================================================================o Last Updated: June 8th, 1997 TOTAL MUDS LISTED: 808 o=======================================================================o o=======================================================================o Muds Beginning With: A o=======================================================================o Mud : Aacena: The Fatal Promise Code Base : Envy 2.0 Telnet : mud.usacomputers.com 6969 [204.215.32.27] WWW : None Description : Aacena: The Fatal Promise: Come here if you like: Clan Wars, PKilling, Role Playing, Friendly but Fair Imms, in depth quests, Colour, Multiclassing*, Original Areas*, Tweaked up code, and MORE! *On the way in The Fatal Promise is a small mud but is growing in size and player base.
    [Show full text]
  • Creating a PDF Document Using Pdflatex
    Distributed Technology-Sustained Pervasive Applications (v2.6) – Kim J.L. Nevelsteen arXiv:1604.02892v1 [cs.CY] 11 Apr 2016 Distributed Technology-Sustained Pervasive Applications (v2.6) Kim J.L. Nevelsteen Kim J.L. Nevelsteen, Stockholm University, 2015. ISBN 978-91-7649-277-2 ISSN 1101-8526 DSV Report Series No. 15-016 Printer: Holmbergs, Malmö 2015 Distributor: Department of Computer and Systems Sciences Cover image: rendition of [Lankoski et al. 2004, Figure 2], see pp. 32 Abstract Technology-sustained pervasive games, contrary to technology-supported pervasive games, can be understood as computer games interfacing with the physical world. Pervasive games are known to make use of ‘non-standard input devices’ and with the rise of the Internet of Things (IoT), pervasive applications can be expected to move beyond games. This dissertation is requirements- and development-focused Design Science research for distributed technology-sustained pervasive applications, incorporating knowledge from the domains of Distributed Computing, Mixed Reality, Context-Aware Computing, Geographical Information Systems and IoT. Computer video games have existed for decades, with a reusable game engine to drive them. If pervasive games can be understood as computer games interfacing with the physical world, can computer game engines be used to stage pervasive games? Considering the use of non-standard input devices in pervasive games and the rise of IoT, how will this affect the architectures supporting the broader set of pervasive applications? The use of a game engine can be found in some existing pervasive game projects, but general research into how the domain of pervasive games overlaps with that of video games is lacking.
    [Show full text]
  • The State of Play
    NYLS Law Review Vols. 22-63 (1976-2019) Volume 49 Issue 1 State of Play Article 1 January 2005 The State of Play Beth Simone Noveck New York Law School Follow this and additional works at: https://digitalcommons.nyls.edu/nyls_law_review Part of the Gaming Law Commons, and the Internet Law Commons Recommended Citation Beth S. Noveck, The State of Play, 49 N.Y.L. SCH. L. REV. (2004-2005). This Article is brought to you for free and open access by DigitalCommons@NYLS. It has been accepted for inclusion in NYLS Law Review by an authorized editor of DigitalCommons@NYLS. \\server05\productn\N\NLR\49-1\NLR116.txt unknown Seq: 1 8-DEC-04 9:59 THE STATE OF PLAY BETH SIMONE NOVECK* Before the World Wide Web, science fiction writer Neal Ste- phenson conceived of the Metaverse,1 the first virtual world. The imaginary Metaverse is the model — the city on a hill — that pro- grammers have been attempting to recreate for the “real” virtual world. In Stephenson’s vision, the Metaverse was not just a place for play. His Dickensian main character, Hiro Protagonist, plugs into a virtual office where he interacts with other characters as well as with artificial intelligence daemons.2 We are just beginning to realize Stephenson’s fantasy with vir- tual (sometimes called digital or synthetic) worlds that are currently used for play and social interaction but soon will be widely adopted as spaces for research,3 education,4 job recruiting,5 and work life.6 * Associate Professor and Director, Institute for Information Law and Policy, New York Law School; J.D.
    [Show full text]
  • The Laws of the Virtual Worlds
    California Law Review VOL. 92 JANUARY 2004 No. 1 Copyright © 2004 by California Law Review, Inc., a California Nonprofit Corporation The Laws of the Virtual Worlds F. Gregory Lastowkat & Dan Hunterl TABLE OF CONTENTS Introduction .............................................................................................3 A . V irtual W orlds ...........................................................................4 B. On the Real and the Virtual .......................................................7 I. A Virtual-World Primer ..................................................................14 A . W riting the W orld ....................................................................14 B. Drawing the World ..................................................................21 II. V irtual Properties ..........................................................................29 A. The Existence of Property in Virtual Worlds ...........................30 B. Early Conceptions of Virtual Property .....................................34 C. The Descriptive Account of Virtual Property .......................... 37 1. Metaphysical Problems ....................................................40 2. Temporal Problems ...........................................................42 D. The Normative Account of Virtual Property ............................43 1. Utilitarian Theories of Virtual Property ............................44 2. Lockean Theories of Virtual Property ...............................46 3. Personality Theories of Virtual Property ............................48
    [Show full text]
  • How to Play the Game?
    How to play the game? A study on MUD player types and their real life personality traits R.L.M. van Meurs, s395420 Master Thesis Leisure Studies Theme: Virtual Communities Supervisor: Drs. E.J. van Ingen Second Corrector: Dr. Ir. A. Bargeman Department of Social Sciences August 6th 2007, Tilburg Contents Contents II Abstract IV Preface V List of Abbreviations and MUD-related Concepts VII 1. Introduction 1 1.1 Laying Out the Research 2 1.1.1 Towards Different Playing Styles 3 1.1.2 Online versus Offline 4 1.2 Research Question, Goal and Relevance 5 2. Online Playing Styles and Offline Characteristics 7 2.1 Bartle’s Typology of Player Types 8 2.1.1 The Four Player Types 8 2.1.2 The Player Types Model and Dynamics 10 2.1.3 The Bartle Test 11 2.2 Criticism on Bartle’s Player Types 11 2.2.1 Yee’s Player Motivations 12 2.2.2 The Social versus Game-Like Debate 14 2.3 Alternative Ways of Categorizing Player Types and Motivations 15 2.3.1 Hierarchical Categorizations 16 2.3.2 Other Classifications 17 2.3.3 Relevance of Alternative Classifications 17 2.4 The Big Five / Offline Character Traits 18 2.4.1 Extraversion 19 2.4.2 Agreeableness 20 2.4.3 Conscientiousness 21 2.4.4 Emotional Stability 21 2.4.5 Intellect, Openness or Imagination 22 2.5 The Conceptual Model and Expectations 23 2.5.1 Summary of the Theory 23 2.5.2 The Conceptual Model and Expectations 24 II 3.
    [Show full text]