Derivation of three new human embryonic stem cell lines

Human embryonic stem cells are pluripotent cells capable of extensive self-renewal and differentiation to all cells of the embryo proper. Here, we describe the derivation and characterization of three Sydney IVF human embryonic stem cell lines not already reported elsewhere, designated SIVF001, SIVF002, and SIVF014. The cell lines display typical compact colony morphology of embryonic stem cells, have stable growth rates over more than 40 passages and are cytogenetically normal. Furthermore, the cell lines express pluripotency markers including Nanog, Oct4, SSEA3 and Tra-1-81, and are capable of generating teratoma cells derived from each of the three germ layers in immunodeficient mice. These experiments show that the cell lines constitute pluripotent stem cell lines.     

Selective fatty acid mobilization in the American mink (Mustela vison) during food deprivation

The mobilization of fatty acids (FAs) during food deprivation is a selective process in laboratory rodents and humans. The site-specific differences in adipose tissue functions - e.g. energy storage versus insulation - should also affect the use of different FAs. To study this, 16 female minks were randomly assigned into the control group or fasted for 5 days. Preferential mobilization of n-3 polyunsaturated FAs (PUFAs) during fasting caused a decrease in the n-3/n-6 PUFA ratio in fat and liver. In addition, the minks utilized short-chain FAs efficiently in all fat depots, but long-chain FAs - 20:0, 20:1n-11, 20:1n-9, 22:1n-11 and 24:1n-9 - were preserved. The number of double bonds in the FA chain correlated positively with mobilization rate in the retroperitoneal fat. The observed negative correlation between mobilization rate and the location of the first double bond from the methyl end may be due to peroxisomal chain-shortening of long-chain FAs and not the double bond position per se. As a result, minks are able to preserve a low melting point and fluidity of the subcutaneous fat depots, which would be essential to a Northern semi-aquatic mammal.     

Physiological adaptations to fasting in an actively wintering canid, the Arctic blue fox (Alopex lagopus)

This study investigated the physiological adaptations to fasting using the farmed blue fox (Alopex lagopus) as a model for the endangered wild arctic fox. Sixteen blue foxes were fed throughout the winter and 32 blue foxes were fasted for 22 d in Nov-Dec 2002. Half of the fasted blue foxes were food-deprived again for 22 d in Jan-Feb 2003. The farmed blue fox lost weight at a slower rate (0.97-1.02% body mass d(-1)) than observed previously in the arctic fox, possibly due to its higher initial body fat content. The animals experienced occasional fasting-induced hypoglycaemia, but their locomotor activity was not affected. The plasma triacylglycerol and glycerol concentrations were elevated during phase II of fasting indicating stimulated lipolysis, probably induced by the high growth hormone concentrations. The total cholesterol, HDL- and LDL-cholesterol, urea, uric acid and total protein levels and the urea:creatinine ratio decreased during fasting. Although the plasma levels of some essential amino acids increased, the blue foxes did not enter phase III of starvation characterized by stimulated proteolysis during either of the 22-d fasting procedures. Instead of excessive protein catabolism, it is liver dysfunction, indicated by the increased plasma bilirubin levels and alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase activities, that may limit the duration of fasting in the species.     

Synthesis and CB1 receptor activities of dimethylheptyl derivatives of 2-arachidonoyl glycerol (2-AG) and 2-arachidonyl glyceryl ether (2-AGE)

Results from a factor analysis and activity studies of commercially available endocannabinoid-type compounds set the starting point for the current study where dimethylheptyl (DMH) analogues of two endocannabinoids, 2-arachidonoyl glycerol (2-AG) and 2-arachidonyl glyceryl ether (2-AGE), were synthesized and their ability to activate the CB1 receptors was determined by the [35S]GTPgammaS binding assay using rat cerebellar membranes. The main goal of the study was to examine how the DMH end tail affects the activity properties of 2-AG (1) and its stable ether (2) and urea analogues (5). The importance of the chain length was also explored by synthesizing 2-AG and 2-AGE derivatives (3 and 4) possessing the chain length C21 instead of C22. Replacement of the pentyl end chain with the DMH resulted in distinct potency decrease as compared to the reference compounds. The modification did not have such a strong impact on the efficacy values. In fact, the efficacy of the derivatives of 2-AGE (2 and 4) was comparable or even improved. Introducing a more stable and hydrophilic urea bond led to a dramatic decrease in biological activity.     

Climate-related challenges in long-term management of Säkylän Pyhäjärvi (SW Finland)

Säkylän Pyhäjärvi (SW Finland) is an example of a large and shallow lake suffering from eutrophication. During the last 20 years, the quality and general usability of water in Pyhäjärvi have shown considerable variation driven by both a variety of human activities and climate-related factors such as wet and dry years. The lake has been thoroughly studied for decades and has been the object of comprehensive restoration activities both in the catchment and in the lake since the 1990s. Large variety of water protection measures like wetlands, sedimentation ponds and filtering systems have been implemented in the catchment area to reduce external nutrient load. Another important tool for Pyhäjärvi restoration is biomanipulation, done by local commercial fishermen in winter. Twenty-five percent of the annual phosphorus input is removed with fish catch. Currently, restoration work is facing new challenges: short or even nearly missing ice cover period and increased winter time nutrient load from the catchment. In the 2000s, there were 3 years with exceptionally short ice period, allowing only brief winter seining periods. Consequently, the biomanipulation catch was very low in 2007 and 2008 leading to observable food web effects. Phosphorus load was especially high in winters 2006/2007 and 2008/2009. On the basis of the data of 1987–2008, we have tested the hypothesis if climate-related winter time variables like phosphorus load, air temperature and precipitation would affect the water quality of the lake in following summer, here measured as chlorophyll a concentration in the lake water. A linear model has been used and a validation procedure has been performed to select the best variables. Our results indicate some of the linkages between climate-related catchment processes and the ecological status of the lake.     

A barley (Hordeum vulgare L.) LEA3 protein, HVA1, is abundant in protein storage vacuoles

The HVA1 protein belongs to the LEA3 group, which is expressed during the late stage of seed maturation. It is also induced by exogenous abscisic acid (ABA) and a variety of environmental stresses in germinating barley (Hordeum vulgare L.). In the present work, the potential role of HVA1 was investigated by studying its tissue distribution and subcellular localization in mature and stressed seeds by immuno-microscopic methods. In the mature seed, HVA1 protein was detected in all tissues except the non-living starchy endosperm. During germination the amount of HVA1 protein decreased but did not totally disappear. Incubation with 100 μM ABA, cold treatment or drought stress dramatically increased HVA1 expression in the germinated seed. In this work, the distribution of a LEA3 group protein was studied in a cereal seed for the first time by immuno-electron microscopy. In the scutellum and aleurone layer, HVA1 was localized both in the cytoplasm and protein storage vacuoles (PSVs). HVA1 protein was found to be threefold more abundant in PSVs than in the cytoplasm of an unstressed seed tissue. The ratio increased with ABA or stress treatments to at least ninefold. The role of HVA1 in PSVs remains unclear: a previously suggested possibility is ion sequestration to prevent precipitation during stress. On the other hand, HVA1 protein could also be degraded in PSVs. HVA1 protein does not have the signal peptide typical of proteins which are glycosylated and targeted into the vacuole via the Golgi complex. Because HVA1 is not glycosylated, it may use an alternative, ER-independent vacuolar pathway, also found in yeast cells.     

Production of extracellular enzymes and cyclosporin byTolypocladium inflatum and morphologically related fungi

Summary Tolypocladium inflatum, the producer of cyclosporins, and morphologically related fungi from the generaTolypocladium, Beauveria, Fusarium andNeocosmospora produced different levels of cyclosporin A and of extracellular lipase and chitinase. However, entomopathogenically important protease activity was not detected.     

Prey depletion by the foraging of the Eurasian treecreeper, Certhia familiaris, on tree-trunk arthropods

We examined to what extent breeding insectivorous treecreepers, Certhia familiaris, affect the abundance and the mean size of their prey population on the surface of tree trunks. In order to determine foraging pressure on tree trunks, we observed the parent birds' foraging behaviour in marked squares (25Ꭱ m) at a short (10 m) and long distance (90 m) from the nest, when the nestlings were near fledging. Immediately after fledging, we measured the remaining food abundance on a sample of tree trunks near to and far from the nest. All arthropods longer than 1 mm were collected and identified to family level and their length was measured. Treecreepers foraged for significantly less time on trunks far from the nest than on trunks close to the nest (5 s vs 186 s). Consequently, treecreepers were found to deplete food abundance on trunks close to the nest. During the nesting period, parent birds removed almost twice as many spiders and other arthropods (excluding Formica ants) from the tree trunks close to the nest than from those further away. The size distribution of arthropods was the same between frequently and seldom-used tree trunks, suggesting that arthropod consumption by treecreepers was not size selective. Our direct measurements on the abundance of arthropods provide rare evidence for the ability of predators to deplete their food resources to a large extent.