Hyperthermia and increased physical activity in the fasting American mink Mustela Vison

The aim of this study was to investigate the thermoregulatory adaptations to fasting in a medium-sized mustelid with a high metabolic rate and energetic requirements. Sixteen farm-bred female American minks, Mustela vison, were divided into a fed control group and an experimental group fasted for 5 days. The deep body temperature (T(b)) of the minks was registered at 10 min intervals with intraabdominal thermosensitive loggers and the locomotor activity was videotaped continuously for 5 days during the fasting procedure. The T(b) of the fasted animals increased during the first day of fasting and decreased during the second day. After 3-4 days of fasting, the levels of physical activity and T(b) of the fasted minks increased above the levels of the fed animals. Significant increases in these parameters were observed at the beginning of the working day on the farm, during the feeding of the fed animals and around midnight. It is concluded that the mink differs from previously studied homeotherms in thermoregulatory and behavioral responses to fasting probably due to its high energy requirements and predatory success.     

Wound-induced oxidative responses in mountain birch leaves

AIMS: The aim of the study was to examine oxidative responses in subarctic mountain birch, Betula pubescens subsp. czerepanovii, induced by herbivory and manual wounding. METHODS: Herbivory-induced changes in polyphenoloxidase, peroxidase and catalase activities in birch leaves were determined. A cytochemical dye, 3,3-diaminobenzidine, was used for the in situ and in vivo detection of H2O2 accumulation as a response to herbivory and wounding. To localize peroxidase activity in leaves, 10 mm H2O2 was applied to the dye reagent. KEY RESULTS: Feeding by autumnal moth, Epirrita autumnata, larvae caused an induction in polyphenoloxidase and peroxidase activities within 24 h, and a concomitant decrease in the activity of antioxidative catalases in wounded leaves. Wounding also induced H2O2 accumulation, which may have both direct and indirect defensive properties against herbivores. Wound sites and guard cells showed a high level of peroxidase activity, which may efficiently restrict invasion by micro-organisms. CONCLUSION: Birch oxidases together with their substrates may form an important front line in defence against herbivores and pathogens.     

History of agriculture in Mikkeli Orijärvi,eastern Finland as reflected by palynological and archaeological data

The introduction and development of cultivation in eastern Finland was studied by pollen and charcoal analysis of a palaeomagnetically dated sediment profile from Lake Orijärvi, in the vicinity of permanent prehistoric fields. The earliest changes of possibly anthropogenic origin are visible in the pollen data from 1630 b.c. onwards and indications of human impact become more evident from 500 b.c. onwards. According to finds of cereal pollen and AMS-dating of charred cereal grains from the oldest field layer, the onset of cultivation can be dated to the Merovingian period around a.d. 600. To a significant extent the pollen data reflect only the cultivation of Secale during the first 600 years. The marked intensification of agricultural activities including cultivation in permanent fields only becomes evident in the pollen data from about a.d. 1050 to 1080 onwards and the most intensive land use phase dates to a.d. 1300–1965. Archaeological and palaeoecological material indicate that swidden cultivation and permanent field cultivation were in use simultaneously during the late Iron Age. The combination of these techniques together with animal husbandry and hunting formed a subsistence strategy in the climatic border-zone outside the centres of the agricultural core areas.     

The N terminus of the adhesion G protein-coupled receptor GPR56 controls receptor signaling activity

GPR56 is an adhesion G protein-coupled receptor that plays a key role in cortical development. Mutations to GPR56 in humans cause malformations of the cerebral cortex, but little is known about the normal function of the receptor. We found that the large N terminus (NT) of GPR56 is cleaved from the rest of the receptor during processing but remains non-covalently associated with the seven-transmembrane region of the receptor, as indicated by coimmunoprecipitation of the two GPR56 fragments from both transfected cells and native tissue. We also found that truncation of the GPR56 NT results in constitutive activation of receptor signaling, as revealed by increased GPR56-stimulated signaling upon transfection of HEK-293 cells with truncated GPR56, greatly enhanced binding of β-arrestins by truncated GPR56 relative to the full-length receptor, extensive ubiquitination of truncated GPR56, and cytotoxicity induced by truncated GPR56 that could be rescued by cotransfection of cells with β-arrestin 2. Furthermore, we found that the GPR56 NT is capable of homophilic trans-trans interactions that enhance receptor signaling activity. On the basis of these findings, we suggest a model of receptor activation in which the large N terminus of GPR56 constrains receptor activity but N-terminal interactions (GPR56 NT with an extracellular ligand and/or GPR56 NT homophilic trans-trans associations) can remove this inhibitory influence of the N terminus to activate receptor signaling.     

Habitat heterogeneity drives the geographical distribution of beta diversity: the case of New Zealand stream invertebrates

To define whether the beta diversity of stream invertebrate communities in New Zealand exhibits geographical variation unexplained by variation in gamma diversity and, if so, what mechanisms (productivity, habitat heterogeneity, dispersal limitation, disturbance) best explain the observed broad‐scale beta diversity patterns. We sampled 120 streams across eight regions (stream catchments), spanning a north–south gradient of 12° of latitude, and calculated beta diversity (with both species richness and abundance data) for each region. We explored through a null model if beta diversity deviates from the expectation of stochastic assembly processes and whether the magnitude of the deviation varies geographically. We then performed multimodel inference analysis on the key environmental drivers of beta diversity, using Akaike's information criterion and model and predictor weights to select the best model(s) explaining beta diversity. Beta diversity was, unexpectedly, highest in the South Island. The null model analysis revealed that beta diversity was greater than expected by chance in all eight regions, but the magnitude of beta deviation was higher in the South Island, suggesting differences in environmental filtering and/or dispersal limitation between North and South Island. Habitat heterogeneity was the predominant driver of beta diversity of stream macroinvertebrates, with productivity having a secondary, and negative, contribution. This is one of the first studies accounting for stochastic effects while examining the ecological drivers of beta diversity. Our results suggest that local environmental heterogeneity may be the strongest determinant of beta diversity of stream invertebrates, more so than regional‐ or landscape‐scale variables.     

Di(azacrown) conjugates of 2'-O-methyl oligoribonucleotides as sequence-selective artificial ribonucleases

Functionalized 2'-O-methyl oligoribonucleotides bearing two 3-(3-hydroxypropyl)-1,5,9-triazacyclododecane ligands attached via a phosphodiester linkage to a single non-nucleosidic building block have been prepared on a solid-support by conventional phosphoramidite chemistry. The branching units employed for the purpose include 2,2-bis(3-hydroxypropylaminocarbonyl)propane-1,3-diol, 2-hydroxyethyl 3'-O-(2-hydroxyethyl)-beta-D-ribofuranoside, and 2-hydroxyethyl 2'-O-(2-hydroxyethyl)-beta-D-ribofuranoside. Each of these has been introduced as a phosphoramidite reagent either into the penultimate 3'-terminal site or in the middle of the oligonucleotide chain. The dinuclear Zn2+ complexes of these conjugates have been shown to exhibit enhanced catalytic activity over their monofunctionalized counterpart, the 3'-terminal conjugate derived from 2-hydroxyethyl 3'-O-(2-hydroxyethyl)-beta-D-ribofuranoside being the most efficient cleaving agent. This conjugate cleaves an oligoribonucleotide target at a single phosphodiester bond and shows turnover and 1000-fold cleaving activity compared to the free monomeric Zn2+ chelate of 1,5,9-triazacyclododecane.     

The Generation of Six Clinical-Grade Human Embryonic Stem Cell Lines

The edict for producing clinically compliant human embryonic stem cells (hESCs) necessitates adherence to global ethical standards for egg procurement and embryo donation, conformity to regulations controlling clinical-grade cell and tissue product development, and compliance with current good tissue and manufacturing practices (cGTPs and cGMPs, respectively). For example, the U.S. FDA Center for Biologics Evaluation and Research recently promulgated regulations regarding human cells and cellular-based products (HCT/Ps) intended for tissue repair or replacement. Issued under Code of Federal Regulations parts 1270 and 1271 (Code of Federal Regulations, 2006a, 2006b), the rules are broadened by requirements for donor selection and cGMPs for HCT/Ps. By adhering to regulations and in anticipation of future standards, we have generated six clinical-grade hESC lines. Here we describe their manufacture, from embryo procurement to line characterization, including sterility and pathogen testing (Figure 1). To our knowledge, the lines represent the first to have been produced in compliance with international regulatory requirements, suitable for therapeutic use.     

Isolation over 35 years in a heated biotest basin causes selection on MHC class IIß genes in the European perch (Perca fluviatilis L.)

Genes that play key roles in host immunity such as the major histocompatibility complex (MHC) in vertebrates are expected to be major targets of selection. It is well known that environmental conditions can have an effect on host–parasite interactions and may thus influence the selection on MHC. We analyzed MHC class IIß variability over 35 years in a population of perch (Perca fluviatilis) from the Baltic Sea that was split into two populations separated from each other. One population was subjected to heating from cooling water of a nuclear power plant and was isolated from the surrounding environment in an artificial lake, while the other population was not subjected to any change in water temperature (control). The isolated population experienced a change of the allelic composition and a decrease in allelic richness of MHC genes compared to the control population. The two most common MHC alleles showed cyclic patterns indicating ongoing parasite–host coevolution in both populations, but the alleles that showed a cyclic behavior differed between the two populations. No such patterns were observed at alleles from nine microsatellite loci, and no genetic differentiation was found between populations. We found no indications for a genetic bottleneck in the isolated population during the 35 years. Additionally, differences in parasitism of the current perch populations suggest that a change of the parasite communities has occurred over the isolation period, although the evidence in form of in‐depth knowledge of the change of the parasite community over time is lacking. Our results are consistent with the hypothesis of a selective sweep imposed by a change in the parasite community.     

EcM fungal community structure, but not diversity, altered in a Pb-contaminated shooting range in a boreal coniferous forest site in Southern Finland

Boreal forests contain diverse fungal communities that form essential ectomycorrhizal symbioses with trees. To determine the effects of lead (Pb) contamination on ectomycorrhizal fungal communities associated with the dominant pine (Pinus sylvestris L.), we surveyed sporocarps for 3 years, analyzed morphotyped ectomycorrhizal root tips by direct sequencing, and 454-sequenced fungal communities that grew into in-growth bags during a 2-year incubation at a shooting range where sectors vary in the Pb load. We recorded a total of 32 ectomycorrhizal fungi that formed conspicuous sporocarps, 27 ectomycorrhizal fungal phylotypes from 294 root tips, and 116 ectomycorrhizal fungal operation taxonomic unit (OTUs) from a total of 8194 internal transcribed spacer-2 454 sequences. Our ordination analyses by nonparametric multidimensional scaling (NMS) indicated that the Pb enrichment induced a shift in the ectomycorrhizal community composition. This was visible as indicative trends in the sporocarp and root tip data sets, but was explicitly clear in the communities observed in the in-growth bags. The compositional shift in the ectomycorrhizal community was mainly attributable to an increase in the frequencies of OTUs assigned to genus Thelephora and to a decrease in the OTUs assigned to Pseudotomentella, Suillus, and Tylospora in Pb-contaminated areas when compared with the control. While the compositional shifts are clear, their functional consequences for the dominant trees or soil ecosystem function remain undetermined.