Humane Papillomvirus-Infektionen beim CUP-Syndrom des Kopf-Hals-Bereichs

In der vorliegenden Arbeit wird die Prävalenz der Infektion mit Humanen Papillomviren in CUP-Syndromen des Kopf-Hals-Bereichs ermittelt und untersucht, ob mittels dieser Prävalenz auf einen bestimmten Tumorausgangspunkt geschlossen werden kann. Ferner wird untersucht, inwiefern das Expressionsmuster des p16INK4a mit dem HPV-DNA-Status korreliert. Es wird zudem die Bedeutung der Noxen Nikotin und Alkohol für HPV-Infektion, p16INK4a-Expression und Überleben statistisch ausgewertet

Modelling habitat range and seasonality of a new, non-indigenous polychaete Laonome sp (Sabellida, Sabellidae) in Parnu Bay, the north-eastern Baltic Sea

An as-yet-undescribed, non-indigenous polychaete species was found at very high densities in the eastern part of the Baltic Sea in Estonia in 2012. The species belongs to the sabellid genus Laonome Malmgren, 1866, but it could not be assigned to any of the previously described species. To date, the species has established a stable population after surviving a notably cold winter (2012/2013). To study the local distribution and abundance of the species, a spatial grid with some stations repeated seasonally and interannually was sampled in a quantitative manner. Based of the survey data and available environmental data, the variables that contributed significantly to explaining variation in the abundance of the polychaete were determined using the Boosted Regression Trees modelling approach. Molecular barcodes to characterize the identity of the species were also established. The abundance of Laonome sp. exhibited strong seasonal variation, peaking between July and November. Besides seasonality, the quantity of decomposed microalgae in the sediment and wave exposure best explained the variation in abundance. Laonome sp. is now well-established in the Baltic Sea and locally reached high densities in low salinity areas. This non-indigenous polychaete may potentially modify sediment morphology and chemistry and disrupt the natural infaunal communities. Laonome sp. could displace or even completely eliminate some species currently present in the study area and beyond if it spreads; however, it could also facilitate currently-present species through the provision of alternative substrate and/or food. Given its persistence and high abundance in Parnu Bay, colonization of other low-salinity areas of the Baltic Sea can be expected.Peer reviewe

Increasing densities of an invasive polychaete enhance bioturbation with variable effects on solute fluxes

Bioturbation is a key process affecting nutrient cycling in soft sediments. The invasive polychaete genus Marenzelleria spp. has established successfully throughout the Baltic Sea increasing species and functional diversity with possible density-dependent effects on bioturbation and associated solute fluxes. We tested the effects of increasing density of M. arctia, M. viridis and M. neglecta on bioturbation and solute fluxes in a laboratory experiment. Benthic communities in intact sediment cores were manipulated by adding increasing numbers of Marenzelleria spp. The results showed that Marenzelleria spp. in general enhanced all bioturbation metrics, but the effects on solute fluxes varied depending on the solute, on the density and species identity of Marenzelleria, and on the species and functional composition of the surrounding community. M. viridis and M. neglecta were more important in predicting variation in phosphate and silicate fluxes, whereas M. arctia had a larger effect on nitrogen cycling. The complex direct and indirect pathways indicate the importance of considering the whole community and not just species in isolation in the experimental studies. Including these interactions provides a way forward regarding our understanding of the complex ecosystem effects of invasive species.Peer reviewe

Genetic diversity and expanding nonindigenous range of the rhizocephalan Loxothylacus panopaei parasitizing mud crabs in the western North Atlantic

Nonindigenous parasite introductions and range expansions have become a major concern because of their potential to restructure communities and impact fisheries. Molecular markers provide an important tool for reconstructing the pattern of introduction. The parasitic castrator Loxothylacus panopaei, a rhizocephalan barnacle, infects estuarine mud crabs in the Gulf of Mexico and southeastern Florida. A similar parasite introduced into Chesapeake Bay before 1964, presumably via infected crabs associated with oysters from the Gulf of Mexico, was identified as L. panopaei. Our samples of this species during 2004 and 2005 show that the introduced range has expanded as far south as Edgewater, Florida, just north of the northern endemic range limit. The nonindigenous range expanded southward at a rate of up to 165 km/yr with relatively high prevalence, ranging from 30 to 93%. Mitochondrial DNA sequences from the cytochrome oxidase I gene showed that these nonindigenous L. panopaei are genetically distinct from the endemic parasites in southeastern Florida and the eastern Gulf of Mexico. The genetic difference was also associated with distinct host spectra. These results are incompatible with an eastern Gulf source population, but suggest that unrecognized genetic and phenotypic population structure may occur among Gulf of Mexico populations of Loxothvlacu

Evolution of Microsatellite Loci of Tropical and Temperate Anguilla Eels

Anguilla eels are divided into temperate and tropical eels, based on their major distributions. The present study collected two temperate eels, Anguilla japonica and Anguilla anguilla, and two tropical eels, Anguilla marmorata and Anguilla bicolor pacifica, to examine two questions: do temperate and tropical Anguilla eels have different genetic polymorphic patterns?; and do temperate Anguilla japonica and Anguilla anguilla have a closer relationship to each other than to tropical eels? In total, 274 sequences were cloned and sequenced from six conserved microsatellite loci to examine polymorphic patterns of these four catadromous eels. Different mutational events, including substitutions, and repeat-unit deletions and insertions, appeared in major regions, while different point mutations were observed in flanking regions. The results implied that parallel patterns of microsatellite sequences occurred within both tropical and temperate freshwater eels. Consensus flanking sequences of six homologous loci from each of the four species were constructed. Genetic distances ranged from 0.044 (Anguilla bicolor pacifica vs. Anguilla marmorata) to 0.061 (Anguilla marmorata vs. Anguilla anguilla). The tree topology suggests the hypothesis of Anguilla japonica and Anguilla anguilla being a sister group must be rejected

Self-assembled hydrogel fibers for sensing the multi-compartment intracellular milieu

Targeted delivery of drugs and sensors into cells is an attractive technology with both medical and scientific applications. Existing delivery vehicles are generally limited by the complexity of their design, dependence on active transport, and inability to function within cellular compartments. Here, we developed self-assembled nanofibrous hydrogel fibers using a biologically inert, low-molecular-weight amphiphile. Self-assembled nanofibrous hydrogels offer unique physical/mechanical properties and can easily be loaded with a diverse range of payloads. Unlike commercially available E. coli membrane particles covalently bound to the pH reporting dye pHrodo, pHrodo encapsulated in self-assembled hydrogel-fibers internalizes into macrophages at both physiologic (37°C) and sub-physiologic (4°C) temperatures through an energy-independent, passive process. Unlike dye alone or pHrodo complexed to E. coli, pHrodo-SAFs report pH in both the cytoplasm and phagosomes, as well the nucleus. This new class of materials should be useful for next-generation sensing of the intracellular milieu

A Tri-Oceanic Perspective: DNA Barcoding Reveals Geographic Structure and Cryptic Diversity in Canadian Polychaetes

Although polychaetes are one of the dominant taxa in marine communities, their distributions and taxonomic diversity are poorly understood. Recent studies have shown that many species thought to have broad distributions are actually a complex of allied species. In Canada, 12% of polychaete species are thought to occur in Atlantic, Arctic, and Pacific Oceans, but the extent of gene flow among their populations has not been tested.Sequence variation in a segment of the mitochondrial cytochrome c oxidase I (COI) gene was employed to compare morphological versus molecular diversity estimates, to examine gene flow among populations of widespread species, and to explore connectivity patterns among Canada's three oceans. Analysis of 1876 specimens, representing 333 provisional species, revealed 40 times more sequence divergence between than within species (16.5% versus 0.38%). Genetic data suggest that one quarter of previously recognized species actually include two or more divergent lineages, indicating that richness in this region is currently underestimated. Few species with a tri-oceanic distribution showed genetic cohesion. Instead, large genetic breaks occur between Pacific and Atlantic-Arctic lineages, suggesting their long-term separation. High connectivity among Arctic and Atlantic regions and low connectivity with the Pacific further supports the conclusion that Canadian polychaetes are partitioned into two distinct faunas.Results of this study confirm that COI sequences are an effective tool for species identification in polychaetes, and suggest that DNA barcoding will aid the recognition of species overlooked by the current taxonomic system. The consistent geographic structuring within presumed widespread species suggests that historical range fragmentation during the Pleistocene ultimately increased Canadian polychaete diversity and that the coastal British Columbia fauna played a minor role in Arctic recolonization following deglaciation. This study highlights the value of DNA barcoding for providing rapid insights into species distributions and biogeographic patterns in understudied groups

Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs

Interspecific hybridization plays an important role in facilitating adaptive evolutionary change. More specifically, recent studies have demonstrated that hybridization may dramatically influence the establishment, spread, and impact of invasive populations. In Japan, previous genetic evidence for the presence of two non-native congeners, the European green crab Carcinus maenas and the Mediterranean green crab C. aestuarii, has raised questions regarding the possibility of hybridization between these sister species. Here I present analysis based on both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit I (COI) gene which unambiguously argues for a hybrid origin of Japanese Carcinus. Despite the presence of mitochondrial lineages derived from both C. maenas and C. aestuarii, the Japanese population is panmictic at nuclear loci and has achieved cytonuclear equilibrium throughout the sampled range in Japan. Furthermore, analysis of admixture at nuclear loci indicates dramatic introgression of the C. maenas mitochondrial genome into a predominantly C. aestuarii nuclear background. These patterns, along with inferences drawn from the observational record, argue for a hybridization event pre-dating the arrival of Carcinus in Japan. The clarification of both invasion history and evolutionary history afforded by genetic analysis provides information that may be critically important to future studies aimed at assessing risks posed by invasive Carcinus populations to Japan and the surrounding region

The Whereabouts of an Ancient Wanderer: Global Phylogeography of the Solitary Ascidian Styela plicata

Genetic tools have greatly aided in tracing the sources and colonization history of introduced species. However, recurrent introductions and repeated shuffling of populations may have blurred some of the genetic signals left by ancient introductions. Styela plicata is a solitary ascidian distributed worldwide. Although its origin remains unclear, this species is believed to have spread worldwide by travelling on ship's hulls. The goals of this study were to infer the genetic structure and global phylogeography of S. plicata and to look for present-day and historical genetic patterns. Two genetic markers were used: a fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) and a fragment of the nuclear gene Adenine Nucleotide Transporter/ADP-ATP Translocase (ANT). A total of 368 individuals for COI and 315 for ANT were sequenced from 17 locations worldwide. The levels of gene diversity were moderate for COI to high for ANT. The Mediterranean populations showed the least diversity and allelic richness for both markers, while the Indian, Atlantic and Pacific Oceans had the highest gene and nucleotide diversities. Network and phylogenetic analyses with COI and ANT revealed two groups of alleles separated by 15 and 4 mutational steps, respectively. The existence of different lineages suggested an ancient population split. However, the geographic distributions of these groups did not show any consistent pattern, indicating different phylogeographic histories for each gene. Genetic divergence was significant for many population-pairs irrespective of the geographic distance among them. Stochastic introduction events are reflected in the uneven distribution of COI and ANT allele frequencies and groups among many populations. Our results confirmed that S. plicata has been present in all studied oceans for a long time, and that recurrent colonization events and occasional shuffling among populations have determined the actual genetic structure of this species