164 research outputs found
Eusporangiate ferns from the Dakota Formation, Minnesota, USA
No full textFossil records of the eusporangiate fern family Marattiaceae are common in Paleozoic and early Mesozoic sediments. However, whether this family occurred during the Cretaceous and Tertiary is unknown. Within the Marattiaceae, extant species of Marattia are distributed worldwide, while Danaea occurs only in the New World, and Angiopteris and Christensenia show disjunct distributions throughout the Old World tropics, except in Africa. Two previously unknown marattioid ferns, Goolangia minnesotensis Hu, Dilcher, H. Schneid., et Jarzen gen. et sp. nov. and Mesozoisynangia trilobus Hu, Dilcher, H. Schneid., et Jarzen gen. et sp. nov. are described based on charcoalified isolated sporangia and synangia recovered from the Dakota Formation of the Courtland Clay Pit in south central Minnesota. These isolated sporangia and synangia have sessile, thick-walled sporangia and large spore output per sporangium, which is consistent with features of extant eusporangiate ferns. The spore wall ultrastructure of G. minnesotensis and M. trilobus supports affinities with extant Marattiaceae. These fossils provide evidence for the existence of marattioid ferns during the mid-Cretaceous in North America and present the first unequivocal documentation of the Marattiaceae in post-Jurassic times
Genetic interactions with the yeast Q-SNARE VTI1 reveal novel functions for the R-SNARE YKT6
No full textDilcher M, Kohler B, Fischer von Mollard G. Genetic interactions with the yeast Q-SNARE VTI1 reveal novel functions for the R-SNARE YKT6. JOURNAL OF BIOLOGICAL CHEMISTRY. 2001;276(37):34537-34544.SNARE proteins are required for fusion of transport vesicles with target membranes. Previously, we found that the yeast Q-SNARE Vti1p is involved in transport to the cis-Golgi, to the prevacuole/late endosome, and to the vacuole. Here we identified a previously uncharacterized gene, VTS1, and the R-SNARE YKT6 both as multicopy and as low copy suppressors of the growth and vacuolar transport defect in uti1-2 cells. Ykt6p was known to function in retrograde traffic to the cis-Golgi and homotypic vacuolar fusion. We found that VTI1 and YKT6 also interacted in traffic to the prevacuole and vacuole, indicating that these SNARE complexes contain Ykt6p, Vti1p, plus Pep12p and Ykt6p, Vti1p, Vam3p, plus Vam7p, respectively. As Ykt6p was required for several transport steps, R-SNAREs cannot be the sole determinants of specificity. To study the role of the 0 layer in the SNARE motif, we introduced the mutations vti1-Q158R and ykt6-R165Q. SNARE complexes to which Ykt6p contributed a fourth glutamine residue in the 0 layer were nonfunctional, suggesting an essential function for arginine in the 0 layer of these complexes. vti1-Q158R cells had severe defects in several transport steps, indicating that the second arginine in the 0 layer interfered with function
Confusions in orbivirus protein classification
No full textAn extensive comparative analysis of orbivirus genomes revealed four cases of unclear numeration and protein designation, due to confused reference to protein size or segment size by which they are encoded. A concise nomenclature based on type species, sequence homology and functional characteristics independent of segment or protein size is suggested
[Rezension zu:] Gerhard Dilcher, Diego Quaglioni (a cura di, Hg.), Gli inizi del diritto pubblico, 2, Die Anfänge des öffentlichen Rechts, 2. Da Federico I a Federico II, von Friedrich Barbarossa zu Friedrich II., Berlin (Duncker & Humblot) 2008, 421 S., ISBN 978-3-428-13041-2, EUR 28,00.
No full textGerhard Dilcher und Diego Quaglioni setzen mit diesem Band die Veröffentlichung der Ergebnisse einer zweiteiligen Tagung zu den Anfängen des öffentlichen Rechts fort, die in den Jahren 2006 und 2007 in Trient im Centro per gli Studi Storici Italo-Germanici in Verbindung mit der rechtswissenschaftlichen Fakultät der dortigen Universität veranstaltet wurde (vgl. Francia-Recensio 2009/1–Mittelalter). Die Anfänge des öffentlichen Rechts sind in den letzten Jahren verstärkt auf Interesse gestoßen und waren vor kurzem Gegenstand eines von Jacques Krynen und Michael Stolleis herausgegebenen Tagungsbandes zu "Science politique et droit public dans les facultés de droit européennes (XIIIe–XVIIIe siècle), Frankfurt/M. 2008". Trotz des ähnlichen Themas ist die Konzeption beider Bücher sehr verschieden und ergänzt sich in mancher Hinsicht, zumal der geografische Rahmen des Trienter Bandes sich der Zielsetzung der Veranstaltung entsprechend auf Italien und Deutschland zur Zeit der Staufer konzentriert. In beiden Fällen werden die gesamteuropäische Bedeutung und Ausstrahlung der mittelalterlichen italienischen Rechtswissenschaft und wichtiger Autoren wie Bartolus und Baldus deutlich. ..
Use1p is a yeast SNARE protein required for retrograde traffic to the ER
No full textDilcher M, Veith B, Chidambaram S, Hartmann E, Schmitt HD, Fischer von Mollard G. Use1p is a yeast SNARE protein required for retrograde traffic to the ER. EMBO JOURNAL. 2003;22(14):3664-3674.SNAREs on transport vesicles and target membranes are required for vesicle targeting and fusion. Here we describe a novel yeast protein with a typical SNARE motif but with low overall amino acid homologies to other SNAREs. The protein localized to the endoplasmic reticulum (ER) and was therefore named Use1p (unconventional SNARE in the ER). A temperature-sensitive use1 mutant was generated. use1 mutant cells accumulated the ER forms of carboxypeptidase Y and invertase. More specific assays revealed that use1 mutant cells were defective in retrograde traffic to the ER. This was supported by strong genetic interactions between USE1 and the genes encoding SNAREs in retrograde traffic to the ER. Antibodies directed against Use1p co-immunoprecipitated the SNAREs Ufe1p, myc-Sec20p and Sec22p, which form a SNARE complex required for retrograde traffic from the Golgi to the ER, but neither Bos1p nor Bet1p (members of the SNARE complex in anterograde traffic to the Golgi). Therefore, we conclude that Use1p is a novel SNARE protein that functions in retrograde traffic from the Golgi to the ER
Full-length genome sequence of Ntaya virus
No full textPresentation of pyrosequencing data and phylogenetic analysis for the full genome of Ntaya virus, type virus of the Ntaya virus group of the Flaviviridae isolated in Cameroon in 1966
Genetic characterization of Bhanja virus and Palma virus, two tick-borne phleboviruses
No full textThe genomes of Bhanja virus (BHAV) and Palma virus (PALV) two tick-borne viruses hitherto grouped into the Bhanja virus antigenic complex of the Bunyaviridae were determined by pyrosequencing. Phylogenetic analysis groups all three segments of BHAV and PALV into a distinct clade of tick-borne phleboviruses together with the newly described severe fever with thrombocytopenia syndrome virus and Uukuniemi virus. The terminal signature sequences which are signatures for taxonomic grouping and important for virus replication and RNA transcription show marked differences in the L- and S-segments
Genetic characterization of Erve virus, a European Nairovirus distantly related to Crimean-Congo hemorrhagic fever virus
No full textErve virus (ERVEV) is a European Nairovirus that is suspected to cause severe headache (thunderclap headache) and intracerebral hemorrhage. The mode of transmission to humans (ticks or mosquitoes) is still unknown. Currently, no standardized testing method for ERVEV exists and only a small partial sequence of the polymerase gene is available. Here, we present the first complete genome sequence of ERVEV S, M, and L segments. Phylogenetic comparison of the amino acid sequence of the L-protein (RNA-dependent RNA polymerase) revealed only 48 % homology to available L-protein sequences of other Nairoviruses like Crimean-Congo hemorrhagic fever virus, Nairobi sheep disease virus, Hazara virus, Kupe virus, and Dugbe virus. Among themselves, these Nairoviruses show 62-89 % homology in the L-protein sequences. Therefore, ERVEV seems to be only distantly related to other Nairoviruses. The new sequence data can be used for the development of diagnostic methods and the identification of the natural vector
Clarifying Bunyamwera virus riddles of the past
No full textPyrosequencing data and phylogenetic analysis for the full genome of Ilesha virus, Ngari virus and Calovo virus are described clarifying their much discussed relationship within the species Bunyamwera virus of the genus Orthobunyavirus of the Bunyaviridae
Genetic characterization of Yug Bogdanovac virus
No full textWe present pyrosequencing data and phylogenetic analysis for the full genome of Yug Bogdanovac virus (YBV), a member of the Vesicular stomatitis virus serogroup of the Rhabdoviridae isolated from a pool of Phlebotomus perfiliewi sandflies collected in Serbia in 1976. YBV shows very low nucleotide identities to other members of the Vesicular stomatitis virus serogroup and does not contain a reading frame for C′/C proteins
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