@phdthesis{Pietsch2005,
  author    = {Pietsch, Christof},
  title     = {The genetics of species differences within the genus Nasonia ASHMEAD 1904 (Hymenoptera: Pteromalidae)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-14348},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2005},
  abstract  = {The genetics of species differences is an outstanding question in evolutionary biology. How do species evolve to become phenotypically distinct and how is the genetic architecture organized that underlie species differences? Phenotypic diverged traits are supposed to be frequently involved in prezygotic isolation, i.e. they prevent the formation of hybrids, whereas postzygotic isolation occurs when hybrids experience a fitness reduction. The parasitic wasp genus Nasonia represents an appropriate model system to investigate the genetics of species differences as well as the genetics of postzygotic isolation. The genus consists of three species N. vitripennis, N. longicornis and N. giraulti that differ particularly in male traits that are assumed to posses an adaptive significance: courtship behaviour and wing size differences. The courtship behaviour consists of cyclically repeated series of head nods that are separated by pauses. The stereotypic performance allowed to split up the display into distinct courtship components. Males of N. vitripennis bear vestigial forewings and are incapable of flight, whereas N. longicornis wear intermediate sized wings and N. giraulti is fully capable of flying. Nasonia species can produce interspecific hybrids after removing Wolbachia bacteria induced hybrid incompatibilities with antibiotics. Postzygotic isolation occurs to different extent and is asymmetric among reciprocal crosses, e.g. inviability is stronger in the N. vitripennis (\&\#9792;) x N. longicornis (\&\#9794;) cross than in the N. longicornis (\&\#9792;) x N. vitripennis (\&\#9794;) cross. The formation of hybrids allow to study the genetic of species differences in QTL (quantitative trait locus) analyses as well as the genetics of postzygotic isolation causing hybrid inviability. The aim of the study was to investigate the genetic architecture of differences in courtship behaviour and wing size between N. vitripennis and N. longicornis and to assess the genetics of postzygotic isolation to gain clues about the evolutionary processes underlying trait divergence and establishment of reproductive isolation between taxa. In a QTL analysis based on 94 F2-hybrid individuals of an LV cross only few QTL for wing size differences have been found with relatively large effects, although a large proportion of the phenotypic variance remained unexplained. The QTL on courtship behaviour analysis based on 94-F2 hybrid males revealed a complex genetic architecture of courtship behaviour with QTL of large phenotypic effects that explained more than 40 \% of the phenotypic variance in one case. Additionally, an epistatic analysis (non-additive interlocus interaction) of courtship QTL revealed frequent genetic interchromsomal relations leading in some instances to hybrid specific effects, e.g. reversion of phenotypic effects or the transgression of phenotypes. A QTL analysis based on a threefold sample size revealed, however, an overestimation of QTL effects in the analysis based on smaller sample size pointing towards a genetic architecture of many loci with small effects governing the phenotypic differences in courtship behaviour. Furthermore, the the study comprised the analysis of postzygotic isolation in the reciprocal crosses N. vitripennis (\&\#9792;) x N. longicornis (\&\#9794;) versus N. longicornis (\&\#9792;) x N. vitripennis (\&\#9794;) located several loci distributed over different chromosomes that are involved in hybrid incompatibility. The mapping of hybrid incompatibility regions reproduced for the first time the observed asymmetries in the strength of postzygotic isolation in reciprocal crosses of between the more distant related taxa within the genus Nasonia. Stronger postzygotic incompatibilities in the VL cross are supposed to result from the superposition of nuclear-nuclear incompatibilities with nuclear-cytoplasmic incompatibilities, whereas the coincidences of these to types of incompatibilities were found to be much weaker in the reciprocal LV cross.},
  subject      = {Pteromalidae},
  language  = {en}
}
@phdthesis{Jurak2006,
  author    = {Jurak, Igor},
  title     = {The molecular mechanism of the Cytomegalovirus species specificity},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-19233},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2006},
  abstract  = {Viruses have undergone a coevolution with their hosts, resulting in a specific adaptation to them. Consequently, many viruses have a limited host range. Occasionally, viruses acquire an adaptive mutation, which allows infection and replication in a different species as shown recently for the human immunodeficiency virus and influenza virus. Cross-species infections are responsible for the majority of emerging and re-emerging viral diseases. However, little is known about the mechanisms that restrict viruses to a certain host species, and the factors viruses need to cross the species barrier and replicate in a different host. Cytomegaloviruses are prototypes of the beta-herpesvirus subfamily and are highly species specific. They replicate only in cells of their own or a closely related species. The molecular mechanism underlying their species specificity is poorly understood and was investigated in this study. An initial observation showed that murine cytomegalovirus (MCMV) can replicate in human 293 and 911 cells, but not in any other human cells tested. Both cell lines are transformed with adenoviral E1 genes that encode a transcriptional transactivator (E1A) and two suppressors of apoptosis (E1B-55k and E1B-19k). This has led to the hypothesis that these functions are required for MCMV replication in human cells. Further analysis revealed that normal human cells died rapidly after infection of caspase-9-mediated apoptosis. Apoptosis induced by MCMV can be suppressed by broad-spectrum caspase inhibitors, and virus replication can be rescued, indicating a major role of caspases in this process. Furthermore, over-expression of a mitochondria-localized inhibitor of apoptosis, a Bcl-2-like protein, prevented apoptosis induced by this virus. Human cells resistant to apoptosis allowed also an efficient MCMV replication. The important role of Bcl-2-like proteins for cytomegalovirus cross-species infections was subsequently confirmed by inserting the corresponding genes, and other inhibitors of apoptosis and control genes into the MCMV genome. Only recombinant viruses expressing a Bcl-2-like protein were able to replicate in human cells. A single gene of human cytomegalovirus encoding a mitochondrial inhibitor of apoptosis was sufficient to allow MCMV replication in human cells. Moreover, the same principle facilitated replication of the rat cytomegalovirus in human cells. Thus, induction of apoptosis limits rodent cytomegalovirus cross-species infection.},
  subject      = {Cytomegalie-Virus},
  language  = {en}
}
@article{DrenckhahnWeber2020,
  author    = {Drenckhahn, Detlev and Weber, Heinrich E.},
  title     = {Die Nordfriesische Brombeere, Rubus boreofrisicus Drenckhahn \& H. E. Weber, eine endemische Rubus-Art der Westk{\"u}ste von Schleswig-Holstein, Deutschland},
  series = {Forum geobotanicum},
  volume    = {9},
  journal   = {Forum geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2020.0116},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198194},
  pages     = {66-69},
  year      = {2020},
  abstract  = {Rubus boreofrisicus Drenckhahn \& H. E.Weber ist eine bisher unbeschriebene Rubus-Art der Untergattung Rubus, Serie Discolores. Die Endbl{\"a}ttchen der 5-z{\"a}hligen, handf{\"o}rmigen Sch{\"o}sslingsbl{\"a}tter sind breit eif{\"o}rmig bis ann{\"a}hernd rund, unterseits grau-weißlich, oberseits dunkelgr{\"u}n und schwach behaart. Die Sch{\"o}sslinge sind braunrot, kantig bis schwach gefurcht, etwas behaart mit geraden bis schwach gekr{\"u}mmten, 5-8 mm langen, braunroten Stacheln mit heller Spitzenh{\"a}lfte. Die Bl{\"u}tenstiele besitzen Stieldr{\"u}sen. Rubus boreofrisicus kommt h{\"a}ufig im Waldg{\"u}rtel und in der angrenzenden D{\"u}nenheide der nordfriesischen Insel Amrum vor und ist auch 50 km s{\"u}dlich von Amrum in St. Peter-Ording im Westen der Halbinsel Eiderstedt vertreten.},
  subject      = {Rubus},
  language  = {de}
}