Insight into the proteome of the hyperthermophilic Crenarchaeon Ignicoccus hospitalis: the major cytosolic and membrane proteins

Ignicoccus hospitalis, a hyperthermophilic, chemolithoautotrophic Crenarchaeon, is the host of Nanoarchaeum equitans. Together, they form an intimate association, the first among Archaea. Membranes are of fundamental importance for the interaction of I. hospitalis and N. equitans, as they harbour the proteins necessary for the transport of macromolecules like lipids, amino acids, and cofactors between these organisms. Here, we investigated the protein inventory of I. hospitalis cells, and were able to identify 20 proteins in total. Experimental evidence and predictions let us conclude that 11 are soluble cytosolic proteins, eight membrane or membrane-associated proteins, and a single one extracellular. The quantitatively dominating proteins in the cytoplasm (peroxiredoxin; thermosome) antagonize oxidative and temperature stress which I. hospitalis cells are exposed to at optimal growth conditions. Three abundant membrane protein complexes are found: the major protein of the outer membrane, which might protect the cell against the hostile environment, forms oligomeric complexes with pores of unknown selectivity; two other complexes of the cytoplasmic membrane, the hydrogenase and the ATP synthase, play a key role in energy production and conversion

Supportive development of functional tissues for biomedical research using the MINUSHEET(R) perfusion system

Functional tissues generated under in vitro conditions are urgently needed in biomedical research. However, the engineering of tissues is rather difficult, since their development is influenced by numerous parameters. In consequence, a versatile culture system was developed to respond the unmet needs.Optimal adhesion for cells in this system is reached by the selection of individual biomaterials. To protect cells during handling and culture, the biomaterial is mounted onto a MINUSHEET(R) tissue carrier. While adherence of cells takes place in the static environment of a 24 well culture plate, generation of tissues is accomplished in one of several available perfusion culture containers. In the basic version a continuous flow of always fresh culture medium is provided to the developing tissue. In a gradient perfusion culture container epithelia are exposed to different fluids at the luminal and basal sides. Another special container with a transparent lid and base enables microscopic visualization of ongoing tissue development. A further container exhibits a flexible silicone lid to apply force onto the developing tissue thereby mimicking mechanical load that is required for developing connective and muscular tissue. Finally, stem/progenitor cells are kept at the interface of an artificial polyester interstitium within a perfusion culture container offering for example an optimal environment for the spatial development of renal tubules.The system presented here was evaluated by various research groups. As a result a variety of publications including most interesting applications were published. In the present paper these data were reviewed and analyzed. All of the results point out that the cell biological profile of engineered tissues can be strongly improved, when the introduced perfusion culture technique is applied in combination with specific biomaterials supporting primary adhesion of cells

Nutritional Factors Affecting Survivorship and Pupation Rates in Aedes triseriatus

vi, 27 p.Aedes triseriatus is a medically important mosquito species for research as it is a carrier of the La crosse encephalitis virus. In nature, less than 10% of larvae eventually emerge as adults. In this experiment, tree hole habitats were simulated to determine what nutrients were needed for larvae to survive and successfully pupate. Nutrients were added to simulated habitats in the lab. These additions (in encapsulated forms) included protein, cholesterol, cod liver oil (a lipid mixture), palmitic acid and inert glass beads (as a control). Other nutrient additions included glucose and inorganic ions in concentrations found in stemflow (rainwater that runs into tree holes from the sides of trees). Cholesterol was the only treatment that had significantly increased rates of pupation as compared to the controls (ANOVA, p < 0.050). While control treatments showed no pupae, 100% of larvae treated with cholesterol capsules pupated within 40 days. Results from these treatments indicate that protein, cholesterol, cod liver oil and both stemflow products (glucose and inorganic ions) were able to increase larval survivorship and weights relative to the controls. Palmitic acid increased the mortality rate as compared to the controls, but this was possibly due to the handling of the larvae during treatment. These results suggest that sterols are possibly the limiting nutrients (for successful pupation) in A. triseriatus habitats.Department of Entomology. Kellogg Biological Station. Michigan State University. Hickory Corners, Michigan