GMDD: a database of GMO detection methods

Background  

Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed.     

The abundance of additional N-acetyllactosamine units in N-linked tetraantennary oligosaccharides of human Tamm-Horsfall glycoprotein is a donor-specific feature

Previously, treatment of Tamm-Horsfall glycoprotein (THp) from different donors with endo-beta-galactosidase has been shown to liberate a tetra- and a Sd(a)-active pentasaccharide, concluding the presence of N-linked carbohydrate chains containing additional N - acetyllactosamine units. These type of oligosaccharides were not found in a detailed structure elucidation of the carbohydrate moiety of THp of one male donor, suggesting a donor-specific feature for these type of structures. Therefore, THp was isolated from four healthy male donors and each subjected to endo-beta-galactosidase treatment in order to release these tetra- and Sd(a)-active pentasaccharide. Differences were observed in the total amount of released tetra- and Sda-active pentasaccharide of the used donors (42, 470, 478, 718 microg/100 mg THp), indicating that the presence of repeating N-acetyllactosamine units incorporated into the N-glycan moiety of THp is donor specific. Furthermore, a higher expression of the Sd(a) determinant on antennae which display N-acetyllactosamine elongation was observed, suggesting a better accessibility for the beta-N-acetylgalactosaminyltransferase. In order to characterize the N-glycans containing repeating N- acetyllactosamine units, carbohydrate chains were enzymatically released from THp and isolated. The tetraantennary fraction, which accounts for more than 33% of the total carbohydrate moiety of THp, was used to isolate oligosaccharides containing additional N - acetyllactosamine units. Five N-linked tetraantennary oligosaccharides containing a repeating N-acetyllactosamine unit were identified, varying from structures bearing four Sd(a) determinants to structures containing no Sd(a) determinant (see below). One compound was used in order to specify the branch location of the additional N- acetyllactosamine unit, and it appeared that only the Gal-6' and Gal-8' residues were occupied by a repeating N -acetyllactosamine unit.      

Canopy and litter ant assemblages share similar climate–species density relationships

Tropical forest canopies house most of the globe''s diversity, yet little is known about global patterns and drivers of canopy diversity. Here, we present models of ant species density, using climate, abundance and habitat (i.e. canopy versus litter) as predictors. Ant species density is positively associated with temperature and precipitation, and negatively (or non-significantly) associated with two metrics of seasonality, precipitation seasonality and temperature range. Ant species density was significantly higher in canopy samples, but this difference disappeared once abundance was considered. Thus, apparent differences in species density between canopy and litter samples are probably owing to differences in abundance–diversity relationships, and not differences in climate–diversity relationships. Thus, it appears that canopy and litter ant assemblages share a common abundance–diversity relationship influenced by similar but not identical climatic drivers.     

Uptake of Metals by Plants Sharing a Rhizosphere with the Hyperaccumulator Thlaspi caerulescens

The hyperaccumulator Thlaspi caerulescens was grown with Hordeum vulgare and Lepidium heterophyllum in a split pot experiment to examine the effect of rhizosphere interactions on metal uptake. The objective was to assess the viability of such intercropping as either (1) a system of ‘phytoprotection’ for nonaccumulating plants or (2) a means of enhancing phytoextraction with large-biomass crops through increased metal mobilization within the shared rhizosphere. The plants were separated by (1) an impermeable barrier, (2) a permeable root barrier, or (3) no physical barrier to allow different degrees of root interaction. Studies of rhizosphere effects using split pot experiments are subject to considerable uncertainty by the need to relate test results to appropriate control plants. This was resolved by comparing plant metal concentrations to ‘equivalent’ control plants, with the same yield, based on the observed variation in metal concentration with yield under similar growing conditions.

Cadmium concentration in H. vulgare was increased by a factor of 2.4 when it was grown alongside T. caerulescens without a barrier. In contrast, the uptake of zinc by H. vulgare was significantly decreased, probably through metal depletion within the zone of the Zn-hyperaccumulator's rhizosphere. T. caerulescens also apparently increased the concentration of Cd in H. vulgare by a factor of 1.4 when the roots of the two plants were separated by a permeable barrier that allowed movement of soil solution but prevented physical mixing of roots. The concentrations of all the metals studied (Cd, Zn, Cu, Pb, Ni) were greater in T. caerulescens when the hyperaccumulator was grown alongside either L. heterophyllum or H. vulgare without a root barrier — probably through successful exploitation of a greater volume of soil. However, this effect was not seen in the presence of a partial barrier, except in the case of Cu when T. caerulescens was grown alongside H. vulgare.

These results suggest that T. caerulescens may alter conditions in shared rhizospheres and thereby affect the availability of selected metals to neighboring plants. Thus, it is possible that under-sowing some plants with small hyperaccumulators may potentially offer an alternative form of management for marginally contaminated soils. There was limited evidence of an intercropped hyperaccumulator mobilizing selected metals and restricting the availability of others. However, changes in uptake of selected metals by the larger plant may be quite small compared with the requirements of crop protection or the short-term requirements of many land remediation programs.     

A Comparative Study of Snake and Lizard Tongue-flicking,with an Evolutionary Hypothesis

Many lizards and all snakes flick their tongues. It is known that this unique behavioral pattern serves to collect airborne and substrate chemicals which give the animal information via Jacobson's Organ about the location of food, conspecifics, and possibly other environmental factors. However, a comparative topographic analysis of tongue movements in squamate reptiles is lacking, and it might shed light on the evolution of this behavior. In this study, a survey was made of the lizards and snakes which tongue-flick. Observations and films were made of 25 lizard species representing 10 families and 30 snake species representing 5 families. The information from observations and film analyses of representative species was used to hypothesize the steps of the evolution of tongue-flicking from the simple downward extensions of primitive lizards to the complex multiple oscillations of snakes.     

Effects of glucagon and insulin on fatty acid synthesis and glycogen degradation in the perfused liver of normal and genetically obese (ob/ob) mice.

1. Rapid effects of hormones on glycogen metabolism and fatty acid synthesis in the perfused liver of the mouse were studied. 2. In perfusions lasting 2h, of livers from normal mice, glucagon in successive doses, each producing concentrations of 10(-10) or 10(-9)M, inhibited fatty acid and cholesterol synthesis. In perfusions lasting 40--50 min, in which medium was not recycled, inhibition of fatty acid synthesis was only observed with glucagon at concentrations greater than 10(-9)M. This concentration was about two orders of magnitude higher than that required for the stimulation of glycogen breakdown. Glucagon did not inhibit the activity of acetyl-CoA carboxylase, assayed 10 or 20 min after addition of glucagon (10(-9) or 10(-10)M). It is proposed that the action of glucagon on hepatic fatty acid biosynthesis could be secondary in time to depletion of glycogen. Insulin prevented the effect of glucagon (10(-10)M) on glycogenolysis, but not that of vasopressin. 3. Livers of genetically obese (ob/ob) mice did not show significant inhibition of lipid biosynthesis in response to glucagon, although there was normal acceleration of glycogen breakdown. This resistance to glucagon action was not reversed by food deprivation. Livers of obese mice exhibited resistance to the counteraction by insulin of glucagon-stimulated glycogenolysis, which was reversible by partial food deprivation.