Antiphytovirale Aktivität von Rhamnolipid aus Pseudomonas aeruginosa

A rhamnolipid released by Pseudomonas aeruginosa 196 Aa into the culture medium reduced the number of local lesions induced by tobacco mosaic virus on leaves of the hypersensitive host Nicotiana glutinosa L. by up to 90%. The content of potato virus X in the systemically infected host Nicotiana tabacum L. ‘Samsun’ is decreased in inoculated as well as in secondarily infected leaves by up to 50%. In a smaller degree red clover mottle virus is influenced in the systemic host Pisum sativumconvar.speciosum (Dierb.) Alef ‘Nadja’.     

Detection of genetic variants affecting cattle behaviour and their impact on milk production: a genome‐wide association study

Behaviour traits of cattle have been reported to affect important production traits, such as meat quality and milk performance as well as reproduction and health. Genetic predisposition is, together with environmental stimuli, undoubtedly involved in the development of behaviour phenotypes. Underlying molecular mechanisms affecting behaviour in general and behaviour and productions traits in particular still have to be studied in detail. Therefore, we performed a genome‐wide association study in an F₂ Charolais × German Holstein cross‐breed population to identify genetic variants that affect behaviour‐related traits assessed in an open‐field and novel‐object test and analysed their putative impact on milk performance. Of 37 201 tested single nucleotide polymorphism (SNPs), four showed a genome‐wide and 37 a chromosome‐wide significant association with behaviour traits assessed in both tests. Nine of the SNPs that were associated with behaviour traits likewise showed a nominal significant association with milk performance traits. On chromosomes 14 and 29, six SNPs were identified to be associated with exploratory behaviour and inactivity during the novel‐object test as well as with milk yield traits. Least squares means for behaviour and milk performance traits for these SNPs revealed that genotypes associated with higher inactivity and less exploratory behaviour promote higher milk yields. Whether these results are due to molecular mechanisms simultaneously affecting behaviour and milk performance or due to a behaviour predisposition, which causes indirect effects on milk performance by influencing individual reactivity, needs further investigation.     

The interaction of nucleotides and yeast hexokinase

The kinetics of ethenoadenosine triphosphate (?ATP) as the phosphate donor in the phosphoryl transfer reaction of hexokinase were examined to obtain the K_m′s, V's, and K_α's for the nucleotide and sugar. Dissociation constants for eATP and ?ADP with hexokinase were obtained from fluorometric measurements and compared with similar constants obtained kinetically. Other selected nucleoside triphosphates were used as phosphate donors in the hexokinase reaction and their kinetic constants were obtained. Reactions were also performed using two nucleotides simultaneously as phosphorylating substrates for the hexokinase reaction in an attempt to find the individual dissociation constants, K_m′s and K_i′s. These were compared with the K_m′s obtained from using the nucleotides separately in the hexokinase reaction. From these kinetic and fluorescence binding studies, evidence is presented supporting the postulate that the K_m′s are primarily dissociation constants in a random bi-bi mechanism. Analysis of the K_m values provides additional evidence to support the importance of the amino group in position 6 on the purine ring as a hydrogen-bond acceptor during binding. It was found that ?CTP was a much better hexokinase substrate than CTP. These observations suggest that the V for this reaction is highly dependent upon the size of the nucleotide.     

Bone Morphogenetic Protein 7 (BMP-7) Influences Tendon-Bone Integration In Vitro

IntroductionSuccessful graft ingrowth following reconstruction of the anterior cruciate ligament is governed by complex biological processes at the tendon-bone interface. The aim of this study was to investigate in an in vitro study the effects of bone morphogenetic protein 7 (BMP-7) on tendon-bone integration.ResultsIn both models, positive effects of BMP-7 on ALP enzyme activity were observed (p<0.001). Additionally, similar results were noted for LDH activity and lactate concentration. BMP-7 stimulation led to a significant increase in OCN expression. Whereas the effects of BMP-7 on tendon monoculture peaked during an early phase of the experiment (p<0.001), the cocultures showed a maximal increase during the later stages (p<0.001). The histological analysis showed a stimulating effect of BMP-7 on extracellular matrix formation. Organized ossification zones and calcium carbonate-like structures were only observed in the BMP-stimulated cell cultures.DiscussionThis study showed the positive effects of BMP-7 on the biological process of tendon-bone integration in vitro. Histological signs of improved mineralization were paralleled by increased rates of osteoblast-specific protein levels in primary bovine osteoblasts and fibroblasts.ConclusionOur findings indicated a role for BMP-7 as an adjuvant therapeutic agent in the treatment of ligamentous injuries, and they emphasized the importance of the transdifferentiation process of tendinous fibroblasts at the tendon-bone interface.     

On the reconstruction of phylogenetic transformations. The origin of the arthropods

The conditions are outlined under which the body construction of annelids could have been transformed into that of arthropods. As an adaptation to a vagile life and an uptake of food by filtering particles from the sediment, the body was more and more flattened. Thus lateral protrusions, the subsequent pleurotergites, developed, and the parapodia were shifted to a more ventral position and could differentiate into the branched limbs typical for arthropods. This is the condition under which parts of the body wall were kept immobile, so that they could become sclerotized in the form of rigid plates.     

Formin-like 1 (FMNL1) Is Regulated by N-terminal Myristoylation and Induces Polarized Membrane Blebbing

The formin protein formin-like 1 (FMNL1) is highly restrictedly expressed in hematopoietic lineage-derived cells and has been previously identified as a tumor-associated antigen. However, function and regulation of FMNL1 are not well defined. We have identified a novel splice variant (FMNL1γ) containing an intron retention at the C terminus affecting the diaphanous autoinhibitory domain (DAD). FMNL1γ is specifically located at the cell membrane and cortex in diverse cell lines. Similar localization of FMNL1 was observed for a mutant lacking the DAD domain (FMNL1ΔDAD), indicating that deregulation of autoinhibition is effective in FMNL1γ. Expression of both FMNL1γ and FMNL1ΔDAD induces polarized nonapoptotic blebbing that is dependent on N-terminal myristoylation of FMNL1 but independent of Src and ROCK activity. Thus, our results describe N-myristoylation as a regulative mechanism of FMNL1 responsible for membrane trafficking potentially involved in a diversity of polarized processes of hematopoietic lineage-derived cells.     

Generation of Mouse Small Intestinal Epithelial Cell Lines That Allow the Analysis of Specific Innate Immune Functions

Cell lines derived from the small intestine that reflect authentic properties of the originating intestinal epithelium are of high value for studies on mucosal immunology and host microbial homeostasis. A novel immortalization procedure was applied to generate continuously proliferating cell lines from murine E19 embryonic small intestinal tissue. The obtained cell lines form a tight and polarized epithelial cell layer, display characteristic tight junction, microvilli and surface protein expression and generate increasing transepithelial electrical resistance during in vitro culture. Significant up-regulation of Cxcl2 and Cxcl5 chemokine expression upon exposure to defined microbial innate immune stimuli and endogenous cytokines is observed. Cell lines were also generated from a transgenic interferon reporter (Mx2-Luciferase) mouse, allowing reporter technology-based quantification of the cellular response to type I and III interferon. Thus, the newly created cell lines mimic properties of the natural epithelium and can be used for diverse studies including testing of the absorption of drug candidates. The reproducibility of the method to create such cell lines from wild type and transgenic mice provides a new tool to study molecular and cellular processes of the epithelial barrier.