@article{KoziolRadioSmircichetal.2015,
  author    = {Koziol, Uriel and Radio, Santiago and Smircich, Pablo and Zarowiecki, Magdalena and Fern{\´a}ndez, Cecilia and Brehm, Klaus},
  title     = {A novel terminal-repeat retrotransposon in miniature (TRIM) is massively expressed in Echinococcus multilocularis stem cells},
  series = {Genome Biology and Evolution},
  volume    = {7},
  journal   = {Genome Biology and Evolution},
  number    = {8},
  doi       = {10.1093/gbe/evv126},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148306},
  pages     = {2136-2153},
  year      = {2015},
  abstract  = {Taeniid cestodes (including the human parasites Echinococcus spp. and Taenia solium) have very few mobile genetic elements (MGEs) in their genome, despite lacking a canonical PIWI pathway. The MGEs of these parasites are virtually unexplored, and nothing is known about their expression and silencing. In this work, we report the discovery of a novel family of small nonautonomous long terminal repeat retrotransposons (also known as terminal-repeat retrotransposons in miniature, TRIMs) which we have named ta-TRIM (taeniid TRIM). ta-TRIMs are only the second family of TRIM elements discovered in animals, and are likely the result of convergent reductive evolution in different taxonomic groups. These elements originated at the base of the taeniid tree and have expanded during taeniid diversification, including after the divergence of closely related species such as Echinococcus multilocularis and Echinococcus granulosus. They are massively expressed in larval stages, from a small proportion of full-length copies and from isolated terminal repeats that show transcriptional read-through into downstream regions, generating novel noncoding RNAs and transcriptional fusions to coding genes. In E. multilocularis, ta-TRIMs are specifically expressed in the germinative cells (the somatic stem cells) during asexual reproduction of metacestode larvae. This would provide a developmental mechanism for insertion of ta-TRIMs into cells that will eventually generate the adult germ line. Future studies of active and inactive ta-TRIM elements could give the first clues on MGE silencing mechanisms in cestodes.},
  language  = {en}
}
@article{HubertPawlikClausetal.2012,
  author    = {Hubert, Kerstin and Pawlik, Marie-Christin and Claus, Heike and Jarva, Hanna and Meri, Seppo and Vogel, Ulrich},
  title     = {Opc Expression, LPS Immunotype Switch and Pilin Conversion Contribute to Serum Resistance of Unencapsulated Meningococci},
  series = {PLoS One},
  volume    = {7},
  journal   = {PLoS One},
  number    = {9},
  doi       = {10.1371/journal.pone.0045132},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135421},
  pages     = {e45132},
  year      = {2012},
  abstract  = {Neisseria meningitidis employs polysaccharides and outer membrane proteins to cope with human serum complement attack. To screen for factors influencing serum resistance, an assay was developed based on a colorimetric serum bactericidal assay. The screening used a genetically modified sequence type (ST)-41/44 clonal complex (cc) strain lacking LPS sialylation, polysaccharide capsule, the factor H binding protein (fHbp) and MutS, a protein of the DNA repair mechanism. After killing of >99.9\% of the bacterial cells by serum treatment, the colorimetric assay was used to screen 1000 colonies, of which 35 showed enhanced serum resistance. Three mutant classes were identified. In the first class of mutants, enhanced expression of Opc was identified. Opc expression was associated with vitronectin binding and reduced membrane attack complex deposition confirming recent observations. Lipopolysaccharide (LPS) immunotype switch from immunotype L3 to L8/L1 by lgtA and lgtC phase variation represented the second class. Isogenic mutant analysis demonstrated that in ST-41/44 cc strains the L8/L1 immunotype was more serum resistant than the L3 immunotype. Consecutive analysis revealed that the immunotypes L8 and L1 were frequently observed in ST-41/44 cc isolates from both carriage and disease. Immunotype switch to L8/L1 is therefore suggested to contribute to the adaptive capacity of this meningococcal lineage. The third mutant class displayed a pilE allelic exchange associated with enhanced autoaggregation. The mutation of the C terminal hypervariable region D of PilE included a residue previously associated with increased pilus bundle formation. We suggest that autoaggregation reduced the surface area accessible to serum complement and protected from killing. The study highlights the ability of meningococci to adapt to environmental stress by phase variation and intrachromosomal recombination affecting subcapsular antigens.},
  language  = {en}
}