570 Biowissenschaften; Biologie
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- Circus pygargus (1)
- Dipetalogaster maxima (1)
- HTS (1)
- Montagu’s harrier (1)
- QTL (1)
- TGF-β (1)
- additive gene expression (1)
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- cellobiose dehydrogenase (1)
- cyanobacteria (1)
The identification of QTL involved in heterosis formation is one approach to unravel the not yet fully understood genetic basis of heterosis - the improved agronomic performance of hybrid F1 plants compared to their inbred parents. The identification of candidate genes underlying a QTL is important both for developing markers and determining the molecular genetic basis of a trait, but remains difficult owing to the large number of genes often contained within individual QTL. To address this problem in heterosis analysis, we applied a meta-analysis strategy for grain yield (GY) of Zea mays L. as example, incorporating QTL-, hybrid field-, and parental gene expression data.
In this work we describe and test high-throughput methods with the model organism Synechocystis sp. PCC6803. The required technical automation for these processes was achieved with a Tecan Freedom Evo 200 pipetting robot. The cultivation was performed in 2.2 ml deepwell microtiter plates within a cultivation chamber outfitted with programmable shaking conditions, variable illumination, variable temperature, and an adjustable CO2 atmosphere. Each microtiter-well within the chamber functions as a separate cultivation vessel with reproducible conditions. The automated measurement of various parameters such as growth, full absorption spectrum, chlorophyll concentration, MALDI-TOF-MS, as well as a novel vitality measurement protocol, have already been established and can be monitored during cultivation. Measurement of growth parameters can be used as inputs for the system to allow for periodic automatic dilutions and therefore a semi-continuous cultivation of hundreds of cultures in parallel. The system also allows the automatic generation of mid and long term backups of cultures to repeat experiments or to retrieve strains of interest.
Aus mitteleuropäischer Sicht ist die durch Parasiten verursachte und von Sandmücken übertragene Leishmaniose eine in Ländern tropischer und subtropischer Regionen
auftretende Infektionskrankheit. In zunehmendem Maße werden jedoch autochthone Fälle in Mitteleuropa, insbesondere in Süddeutschland, verzeichnet. Dies ist vermutlich auf die globale Erwärmung und die Ausdehnung des Verbreitungsgebietes der Sandmücken nach Norden zurückzuführen. Die vorliegende Arbeit befasst sich mit der Identifizierung und phylogenetischen Charakterisierung der Erreger dieser Fälle. Dazu wurden verschiedene Marker im Leishmaniengenom sequenziert und mit bekannten Arten verglichen. Die untersuchte DNA stammte von autochthonen kutanen Leishmaniosen bei Pferden und einem Rind, die in den letzten zehn Jahren in Deutschland und der Schweiz auftraten. Aufgrund identischer Sequenzen konnten die Parasiten als L. siamensis identifiziert bzw. verifiziert werden, eine erst im Jahr 2008 neu beschriebene Art, die in Thailand humane viszerale Leishmaniose verursacht. Die phylogenetischen Analysen zeigten die Ähnlichkeit von L. siamensis mit weiteren bisher nicht identifizierten Stämmen aus Martinique und Ghana, die kutane Leishmaniose bei Menschen verursachen. Um die Frage zu beantworten, ob sich die Leishmaniose zu einer in Mitteleuropa endemischen zoonotischen Krankheit entwickeln könnte, müssen weitere Studien über kompatible Vektoren, mögliche Reservoire und zur Virulenz durchgeführt werden.
Visceral leishmaniasis (VL), caused by the members of the Leishmania donovani complex, has been responsible for devastating VL epidemics in the Sudan. Multilocus microsatellite and sequence typing studies can provide valuable insights into the molecular epidemiology of leishmaniasis, when applied at local scales. Here we present population genetic data for a large panel of strains and clones collected in endemic Sudan between 1993 and 2001.
During the last decades the ground-breeding Montagu’s harrier ( Circus pygargus , Linnaeus, 1758) has changed its breeding habitats in Europe to agricultural areas in which many local populations would be close to extinction without a special nest protection regime. Although Montagu’s harrier is a well-studied species in terms of ecology and breeding biology, its genetic structure and population genetics are almost unknown. As there is a lack of good genetic markers we developed a set of 19 microsatellite markers comprising 16 new STR markers which were identified by next-generation sequencing (NGS) using 454 shot-gun pyrosequencing of genomic DNA. The STR markers were arranged into three multiplex PCR sets for high throughput genotyping and characterised. The marker set provides a powerful tool for kinship analysis. The combined non-exclusion probability for parent pairs was 1.13* 10-11. Only three loci showed PIC values < 0.50. In total, 121 known family relationships were compared with genetically calculated ones to test the markers suitability for parentage analysis. In 97.5% of all cases full-sibships were accurately determined and 97.6% of all mothers were assigned correctly to their chicks. The present multiplex PCR panels can be used to investigate several hypotheses concerning breeding behaviour, kinship, exchange rates between populations and phylogeography.
Polymer-multiwalled carbon nanotube (MWCNT) nanohybrids, which differ in surface charge have been synthesized to study the bioelectrocatalysis of adsorbed cellobiose dehydrogenase (CDH) from Phanerochaete sordida on gold electrodes. To obtain negatively charged nanohybrids, poly(3-amino-4-methoxybenzoic acid-co-aniline) (P(AMB-A)) was covalently linked to the surface of MWCNTs while modification with p-phenylenediamine (PDA) converted the COOH-groups to positively charged amino groups. Fourier transform infrared spectroscopy (FTIR) measurements verified the p-phenylenediamine (PDA) modification of the polymer-CNT nanohybrids. The positively charged nanohybrid MWCNT-P(AMB-A)-PDA promoted direct electron transfer (DET) of CDH to the electrode and bioelectrocatalysis of lactose was observed. Amperometric measurements gave an electrochemical response with KMapp = 8.89 mM and a current density of 410 nA/cm2 (15 mM lactose). The catalytic response was tested at pH 3.5 and 4.5. Interference by ascorbic acid was not observed. The study proves that DET between the MWCNT-P(AMB-A)-PDA nanohybrids and CDH is efficient and allows the sensorial detection of lactose.
We have re-analyzed previously published gene expression data from ninety-four pancreatic ductal adenocarcinomas (PDAC) samples. We determined the gene expression profile of genes differentially expressed in PDAC compared to non-malignant pancreatic tissue. Using the 100 top-ranked genes, we were able to discriminate between PDAC and non-malignant pancreatic tissue. A hierarchical cluster analysis revealed only a 6 % false discovery rate. The prognostic strength of these discriminative genes was underscored by a SVM classification and 3-fold cross validation with an 89 % correct class assignment. The annotation of the 100 top-ranked genes revealed that most of the genes were involved in the processes of signal transduction, cell adhesion, extracellular matrix organization and cell migration. The most greatly affected signal cascade was the transforming growth factor β receptor signaling pathway, which was significantly enriched in the top-ranked genes. Furthermore, we identified eleven genes that were associated with good prognosis.