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Nucleotide sequences of the D3 expansion segment and its flanking regions of the 28S rDNA gene were used to evaluate phylogenetic relationships among representative sexual and asexual oribatid mites (Oribatida, Acariformes). The aim of this study was to investigate the hypothesis that oribatid mites consist of species-rich clusters of asexual species that may have radiated while being parthenogenetic. Furthermore, the systematic position of the astigmate mites (Astigmata, Acariformes) which have been hypothesised to represent a paedomorphic lineage within the oribatid mites, is investigated. This is the first phylogenetic tree for oribatid mites s.l. (incl. Astigmata) based on nucleotide sequences. Intraspecific genetic variation in the D3 region was very low, confirming the hypothesis that this region is a good species marker. Results from neighbour joining (NJ) and maximum parsimony (MP) algorithms indicate that several species-rich parthenogenetic groups like Camisiidae, Nanhermanniidae and Malaconothridae are monophyletic, consistent with the hypothesis that some oribatid mite groups diversified despite being parthenogenetic. The MP and maximum likelihood (ML) method indicated that the D3 region is a good tool for elucidating the relationship of oribatid mite species on a small scale(genera, families) but is not reliable for large-scale taxonomy, because branches from the NJ algorithm collapsed in the MP and ML tree. In all trees calculated by different algorithms the Astigmata clustered within the oribatid mites, as proposed earlier.

research has revealed that, together with the provision of morphogens and the presentation of adhesion ligands, [ 2 ] the mechanical characteristics of extracellular matrices have a decisive infl uence on cell fate, provoking the development of materials with effective physical properties. [ 3 ] This interplay of biomolecular and biophysical signals thus defi nes an obvious, but until now unmet, need for a new generation of biomaterials that can be selectively and independently tuned for biomolecular properties and physical material parameters. A conceptual basis to address this need is currently missing. As such, we have developed a rational design approach relying on mean fi eld concepts to guide the design of biofunctional matrices. Considering the decisive role of electrostatic interactions in functional assemblies of living matter we selected a system that allows for a far-reaching modulation of structure-determining forces: crosslinking a hydrophilic and fl exible, multi-armed polymer (with four-armed, amino-terminated poly(ethylene glycol) (starPEG) as an example system known for its anti-adhesive characteristics towards proteins, [ 4 ] with a multifunctional, highly charged crosslinker (such as heparin (HEP) or a similarly charged glycosaminoglycan), which can function as a multivalent binding site capable of complexing a plethora of important bioactive molecules. [ 5 ] We explored whether and how the combination of the particular gel components permits varying the physical and biomolecular characteristics of the swollen materials independently.Based on the successful experimental verifi cation of the theoretical predictions and the functionalization of starPEG-heparin gels with adhesive ligand peptides (such as the integrinbinding arginine-glycine-aspartic acid sequence (RGD))) and morphogens (vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2)) through covalent and noncovalent conjugation schemes we were able to illustrate the resulting options for two selected example systems: studying the interplay of matrix elasticity and growth factor presentation in inducing the pro-angiogenic state of human endothelial cells and promoting osteogenic differentiation of human mesenchymal stem cells we identifi ed effective combinations of matrix parameters and demonstrated exciting options for the fully matrix controlled direction of the cells, i.e., removed the Using Mean Field Theory to Guide Biofunctional Materials DesignCell-instructive characteristics of extracellular matrices (ECM) resulting from a subtle balance of biomolecular and biophysical signals must be recapitulated in engineered biomaterials to facilitate regenerative therapies. However, no material explored so far allows the independent tuning of the involved molecular and physical cues due to the inherent correlation between biopolymer concentration and material properties. Addressing the resulting challenge, a rational design strategy for ECM-inspired biohybrid hydrogels based on multi-armed poly(ethylene glycol) and he...