Species identification of Collembola by means of PCR-based marker systems [Elektronische Ressource] / von Ulrich Burkhardt

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2005
• Nombre de lectures: 32
• Langue: Deutsch
• Poids de l'ouvrage: 2 Mo

Extrait

Species identification of Collembola by means of PCR-based
marker systems
Vorgelegt dem Fachbereich 2 (Biologie/Chemie) der Universität Bremen als
Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften
(Dr. rer. nat.)
von
Ulrich Burkhardt
Universität Bremen
Fachbereich II Biologie/Chemie
März 2005Gutachter der Dissertation:
Prof. Dr. Juliane Filser
Dr. Martina Brückner
Tag des öffentlichen Kolloquiums: 6.5.2005Danksagung
Viele Personen haben zum Gelingen dieser Arbeit beigetragen. Insbesondere möchte ich mich
bedanken bei
meiner Betreuerin, Prof. Dr. Juliane Filser, für ihre unermüdliche Begleitung durch alle Fährnisse
des nicht immer einfachen Themas,
allen Mitgliedern der Abteilung ‘Allgemeine und Theoretische Ökologie’ des UFT für die
angenehme Arbeitsatmosphäre, die meine Arbeit sehr erleichtert hat,
den technischen Assistentinnen Ute Uebers, Annemarie Kissling und Iris Burfeindt, die mich bei
Laborarbeit und Materialbeschaffung unterstützt und in die Bedienung vieler Geräte
eingewiesen haben,
den Kollegen des EDIS-Projektverbundes, insbesondere dem Schwesterprojekt DNA-Tax in
München, für die unkomplizierte Kooperation,
allen Kollegen, die mich freigiebig mit Collembolen aus ihren Sammlungen und Ratschlägen aus
ihrem Erfahrungsschatz versorgt haben: Michael Folger, David Russell, Stefan Scheu, Hans-
Jürgen Schulz, Vibeke Simonsen und Steve Hopkin,
ganz besonders der Arbeitsgruppe Frati in Siena, die mich auch ausgiebig in die Feinheiten der
PCR mit kleinen Organismen eingewiesen hat,
Arne Fjellberg, der großzügig Collembolen aus seiner Sammlung zur Verfügung gestellt und
einige unsichere Artbestimmungen überprüft hat,
den molekularbiologisch tätigen Kollegen in Bremen und umzu, die sich im IFOE-Arbeitskreis
MoBiTech zusammengefunden haben, für zahlreiche Anregungen und Hinweise, insbesondere
zu phylogenetischen Fragen, Erfahrungen mit spezieller Software und den Problemen des
molekularen Laboralltages,
Holger Mebes und Andrea Ruf für die Durchsicht des Manuskripts und kritische Anmerkungen,
Holger Mebes ferner für seine geduldige Einführung in die Collembolentaxonomie,
dem Bundesministerium für Bildung und Forschung BMBF, durch dessen Förderung diese Arbeit
möglich wurde,
der Universität Bremen für die Gewährung eines Promotionsabschlußstipendiums,
und nicht zuletzt meiner Familie für all die Unterstützung, die sie mir zuteil werden ließ.
Allen Beteiligten, auch den nicht aufgeführten, gilt mein herzlicher Dank.Isotoma viridis, Holzschnitt von Hermann Burkhardt. Mit freundlicher Genehmigung des Künstlers.
Die Druckversion dieser Dissertation ist im Shaker Verlag Aachen erschienen (ISBN 3-8322-4498-0). Inhaltsverzeichnis
Inhaltsverzeichnis / Contents............................................................................................. I
1 Introduction and outline ....................................................................................................1
2 Molekulare Taxonomie – Königsweg oder Werkzeug?..................................................15
in Reuter, H., Breckling, B. & Mittwollen, A. (Eds) GfÖ Arbeitskreis Theorie in der Ökologie
9: (2003): Gene, Bits und Ökosysteme (pp. 47-63). Frankfurt/M.: P. Lang Verlag
3 Fast and efficient discrimination of the Isotoma viridis group (Insecta: Collembola) by
PCR-RFLP.......................................................................................................................33
Pedobiologia 48 (2004): 435-443
4 Molecular evidence for a fourth species within the Isotoma viridis group (Insecta,
Collembola) .....................................................................................................................45
Zoologica Scripta 34 (2005): 177-185
5 Systematics of the Protaphorura armata group – a DNA-based approach ....................63
Pedobiologia, submitted
6 Species identification of Collembola by use of DNA fingerprinting..............................85
7 General discussion.........................................................................................................105
Summary.......................................................................................................................125
I 1 Introduction and outline
Introduction and outline
Whatever a character, it can be used in taxonomy
Mikhail B. Potapov
Taxonomy, in the broad sense of definition, identification and re-identification of taxa has found
its actual form in the Linnean binomial classification system and the rules of application that have
been erected since then. In this system, the unit on which all classification bases is the species, but
the species concept itself is a subject of ongoing debate. As a result, different concepts of species
have been developed (e.g. Grant 1981). The biological species concept, as the most widespread,
proposes to identify taxonomic species in accordance with reasonable biological units, i.e. groups
of freely interbreeding natural populations (Mayr 1970) or ”a group of populations possessing
inherited differences that prevent gene exchange with other such groups” (Barton 1989). However,
if we try to arrange biological entities in a classification that best represents the natural system of
descent, we have to be conscious that these entities are a product of the ongoing process of
evolution and thus reflect the variability that is its moving force. A species concept as defined
above will encounter difficulties when regarding organisms that reproduce uniparentally or
asexually (e.g. White 1978, Perkins 2000). Within the area of distribution of a species, distinct
morphotypes may be found that live in sympatry (Olson et al. 2004, Reed et al. 2004). Even the
potential to hybridise may vary between populations assumed to represent the same species (e.g.
Fukami et al. 2004).
Among organisms with limited dispersal potential, differentiated populations easily may be
recognised that are not separated by sexual isolation and thus may be regarded as infraspecific taxa
(Minelli 1993). Such effects have led to some 30 definitions of the term ‘species’, including
biosystematic categories such as sibling species which are morphologically indistinguishable yet
reproductively isolated, coenospecies or colour pattern species, as an attempt to describe
taxonomic levels between species and subspecies, probably representing different stages on the
way to speciation (Grant 1981, Minelli 1993).
Characters are used to define boundaries between taxa for both taxonomic classification and re-
identification. For that purpose, characters should be selected that not only separate one organism
group from another but build up a row of homologous character states and thus may enlighten the
direction of evolution within the group (Duncan & Stuessy 1984). The ability to re-identify a
certain taxon provides the fundament for all further studies that might be helpful to evaluate the
taxonomic status, species boundaries, reproduction and evolutionary history. These studies may
lead to a re-evaluation of the original taxonomic status, which, too, may require a new character set
1 1 Introduction and outline
for taxon identification. However, both disciplines, classification and re-identification, have to
work together to achieve a better understanding of biological diversity and evolution.
About 10-15 millions of species are estimated to exist on our planet (Hammond 1992). Thousands
of taxonomists will be required not only for describing new species but even more for routine
species identification (Hebert et al. 2003). Most of these new species are expected to occur among
prokaryotes, fungi and invertebrates (Janssen et al. 1996, Bachmann 1997, Pace 1997, Klein et al.
1998, Brown 2000, Gravesen et al. 2000, Pryor & Gilbertson 2000, Witt et al. 2003, Pinceel et al.
2004). In most cases these new findings are small organisms bearing few morphological characters
that might be suitable for species identification. Furthermore, variability on both the genetic and
the phenotypic level may lead to intraspecific character variability impeding a correct
identification. Further drawbacks for efficient routine identification are morphological cryptic
species, which still have to be detected, and a lack of efficient morphological characters in juvenile
life stages or even genders (e.g. Bretfeld 1999).
In the functioning of terrestrial ecosystems, soil biodiversity is a crucial factor (Bengtsson 1998,
Copley 2000). Soil communities are among the most species-rich components within terrestrial
ecosystems (Jones & Bradford 2001). For studies dealing with biodiversity and ecology, there is
need for species definition and species identification (Mallet & Willmott 2003), and such
identification is difficult if the species studied are small-sized (e.g. Barrientos 2003, Behan-
Pelletier 2003) or highly diverse in character patterns, thus usually having to be lumped in species
groups (e.g