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Some truffles are expensive and, therefore, are prone to food fraud. A particular problem is the differentiation of high-priced Tuber magnatumtruffles from cheaper Tuber borchiitruffles, both of which are white truffles with similar morphological characteristics. Using an untargeted approach, the volatiles isolated from samples of both species were screened for potential marker compounds by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–TOFMS) and statistical analysis of the obtained semiquantitative data. Results suggested bis(methylsulfanyl)methane and furan-2(5H)-one as compounds characterizing T. magnatumand T. borchii, respectively. Exact quantitation of both volatiles by conventional one-dimensional gas chromatography–mass spectrometry in combination with stable isotopologues of the target compounds as internal standards confirmed both as marker compounds. The method is suitable to be used in the routine analysis for the objective species differentiation of T. magnatumand T. borchii.

We evaluated automated nucleic acid (NA) extraction from a variety of different biological specimens using the QIAsymphony SP instrument. QIAsymphony DNA kits were used for DNA purification from human blood and from diverse human and animal tissue specimens. RNA was isolated from human blood stabilized in PAXgene Blood RNA tubes with the QIAsymphony PAXgene Blood RNA kit, and from human colon and bladder carcinoma biopsies using the QIAsymphony RNA kit. Photometric measurement, gel electrophoresis, and LabChip analysis on an Agilent 2100 Bioanalyzer (Agilent, Palo Alto, California) showed that the purified NAs were highly pure and intact, and that excellent yields were obtained. The DNA purified from blood and tissues performed well in single nucleotide polymorphism (SNP) array analysis, shown by call rates for the Affymetrix Genome-Wide Human 6.0 SNP arrays of > 99%. No significant differences were observed when array results of DNA purified either with magnetic particle technology or silica membrane technology were compared. The quality of the DNA allowed accurate allelic discrimination by TaqMan SNP PCR. Gene expression analyses of purified RNA either by “Human Endogenous Control Panel” TaqMan low-density array or on Affymetrix HG UI33 plus 2.0 GeneChips revealed high concordance between manually purified samples and those extracted on the QIAsymphony SP.

The article examines the spectrum, frequency and behavior of floral visitors in Echinopsis atacamensis subsp. pasacana. The cactus has higher activity and diversity of flower visitors in the population with higher humidity. The frequent visitors of the cactus during the day to gather nectar or pollen are bees, wasps and the giant hummingbird. An unspecialized floral syndrome for Echinopsis atacamensis subsp. pasacana, with both diurnal and nocturnal pollinators is fairly widespread among columnar cacti in the northern hemisphere.

ABSTRACT[URE3] is a non-Mendelian genetic element inSaccharomyces cerevisiae, which is caused by a prion-like, autocatalytic conversion of the Ure2 protein (Ure2p) into an inactive form. The presence of [URE3] allows yeast cells to take up ureidosuccinic acid in the presence of ammonia. This phenotype can be used to select for the prion state. We have developed a novel reporter, in which the ADE2gene is controlled by the DAL5regulatory region, which allows monitoring of Ure2p function by a colony color phenotype. Using this reporter, we observed induction of different [URE3] prion variants (“strains”) following overexpression of the N-terminal Ure2p prion domain (UPD) or full-length Ure2p. Full-length Ure2p induced two types of [URE3]: type A corresponds to conventional [URE3], whereas the novel type B variant is characterized by relatively high residual Ure2p activity and efficient curing by coexpression of low amounts of a UPD-green fluorescent protein fusion protein. Overexpression of UPD induced type B [URE3] but not type A. Both type A and B [URE3] strains, as well as weak and strong isolates of type A, were shown to stably maintain different prion strain characteristics. We suggest that these strain variants result from different modes of aggregation of similar Ure2p monomers. We also demonstrate a procedure to counterselect against the [URE3] state.

Facilitation is an important form of short-term plasticity that occurs in most synapses. At crayfish neuromuscular junctions, basal transmission and facilitation were significantly reduced after presynaptic introduction of “fast” high-affinity calcium buffers, and the decay of facilitation was accelerated. The existence of residual calcium during facilitation was also demonstrated. Computational modeling of three-dimensional buffered Ca2+ diffusion and binding to secretory and facilitation targets suggest that the facilitation site is located away from a secretory trigger mediating exocytosis; otherwise, the facilitation site would be saturated by each action potential. Our simulations account for many characteristics of facilitation and effects of exogenous buffer, and suggest that facilitation is caused by residual calcium gaining access to a site distinct from the secretory trigger through restricted diffusion.

Protein degradation in the vacuole (lysosome) is an important event in cellular regulation. In yeast, as in mammalian cells, a major route of protein uptake for degradation into the vacuole (lysosome) has been found to be autophagocytosis. The discovery of this process in yeast enables the elucidation of its mechanisms via genetic and molecular biological investigations. Here we report the isolation of yeast mutants defective in autophagocytosis ( autmutants), using a rapid colony screening procedure.

Colonial tunicates, unlike vertebrates, undergo transplantation in nature. Rejection or acceptance between colonies of Botryllus is controlled by a single gene locus with multiple alleles. The same genetic region apparently maintains this polymorphism by preventing fertilization between gametes sharing alleles. The Botryllus histocompatibility system may reflect the original adaptive function of ancestral MHC genes.

SYNOPSIS. Colonies of the compound tunicate Botryllus show the capacity for self—nonself discrimination by fusion between separated pieces of the same colony and rejection between pieces of unrelated colonies. We have found that genes controlling this colony specificity are similar to those which cause transplant rejection in the vertebrates. Like the loci within the vertebrate major histocompatibility complex (MHC), Botryllus fusibility (or histocompatibility) genes are highly polymorphic. In Botryllus, the histocompatibility complex also controls self—sterility, and limits cross—fertilization between colonies sharing histocompatibility alleles. The mouse MHC, the H-2 region, is linked to loci which also affect the frequencies of alleles at H-2 loci in mouse populations. Thus both systems contain characters which could act to promote the heterozygous condition at the linked histocompatibility loci. We suggest that such linked characters are responsible for the evolution of allogeneic polymorphism in vertebrates (however currently maintained), and that tunicate fusibility loci may be the evolutionary precursors of vertebrate MHC genes.