Dissipation of bacterially derived C and N through the meso- and macrofauna of a grassland soil

Feeding relationships between organisms may be determined by observations of behaviour in manipulative experiments or, as in more recent times, by the use of stable isotope labelling to trace the passage of ¹³C and ¹⁵N through food webs. Here we introduce living bacteria, labelled with both ¹³C and ¹⁵N into intact soil cores to understand further the movement of bacterially sourced C and N into the meso- and macrofauna of a grassland soil. We found that these groups showed a range of isotope levels which relate to their feeding strategies. Some had no label (e.g. dipterous larvae), whilst others were highly labelled which may indicate a preference for the added bacteria. This latter group included Collembola, generally perceived as being predominantly fungal feeders. This work describes a novel technique which has the potential to provide critical information about the dissipation of bacterially derived C and N through the soil food web.     

Quantitative genetic analysis of condensed tannins in oilseed rape meal

Condensed tannins (proanthocyanidins, PAs) in the seed meal of oilseed rape can potentially have a negative impact on non-ruminant livestock nutrition, particularly because of their ability to form indigestible, astringent or bitter-tasting complexes with proteins. One option to overcome this problem is the breeding of oilseed rape varieties with reduced condensed tannins in the seed coat. This might be achievable via selection of genotypes with thinner seed coats and consequently reduced condensed tannin accumulation (seed coat structural cell mutants), or alternatively by selection of genotypes with reduced biosynthesis of condensed tannins (flavonoid biosynthesis mutants). Both types of transparent testa (TT) mutants are well-characterised in Arabidopsis; however the genetic basis of the yellow-seed trait in the polyploid genome of rapeseed is still not completely understood. In this study, genetic and chemical analyses of PAs were performed in 166 doubled haploid (DH) rapeseed lines from the segregating Brassica napus doubled haploid population YE2-DH (black seed × yellow seed). Using these analyses, the relationship between seed colour and PA fractions in B. napus was investigated with a view to improving the rapeseed meal quality. Proanthocyanidin contents were estimated by vanillin and HPLC assays and the obtained values were used to identify quantitative trait loci. Closely linked molecular markers that were identified during this study for the target traits (seed colour, condensed tannins) can be valuable tools for breeding of new oilseed rape cultivars with reduced levels of antinutritive PA compounds.     

Combinatorial ShcA docking interactions support diversity in tissue morphogenesis

Changes in protein-protein interactions may allow polypeptides to perform unexpected regulatory functions. Mammalian ShcA docking proteins have amino-terminal phosphotyrosine (pTyr) binding (PTB) and carboxyl-terminal Src homology 2 (SH2) domains, which recognize specific pTyr sites on activated receptors, and a central region with two phosphorylated tyrosine-X-asparagine (pYXN) motifs (where X represents any amino acid) that each bind the growth factor receptor-bound protein 2 (Grb2) adaptor. Phylogenetic analysis indicates that ShcA may signal through both pYXN-dependent and -independent pathways. We show that, in mice, cardiomyocyte-expressed ShcA directs mid-gestational heart development by a PTB-dependent mechanism that does not require the pYXN motifs. In contrast, the pYXN motifs are required with PTB and SH2 domains in the same ShcA molecule for the formation of muscle spindles, skeletal muscle sensory organs that regulate motor behavior. Thus, combinatorial differences in ShcA docking interactions may yield multiple signaling mechanisms to support diversity in tissue morphogenesis.     

Electron microscopy of Aujeszky's disease virus in explants of Gasser's ganglion from pigs with a latent infection

Different developmental stages of the Aujeszky's disease virus were demonstrated by electron microscopy in the ultra-thin slices by the cultivated fragments of the Gasserian ganglion (G. g.) of two pigs latently infected with the Aujeszky's disease virus (ADV). In a pig vaccinated with the inactivated vaccine against the disease, the virus was detected in the G. g. cells 186 days after virus challenge, the reactivation of latency being obtained after immunosuppression with dexamethasone. In the non-vaccinated pig the virus was detected in G. g. cells after three months from experimental infection. In the ultra-thin slices the largest amount of virus was located in the nuclei and cytoplasm of satellite and Schwann's cells, in the connective-tissue cells and in the extracellular space. In the ganglion cells the virus was present in the cytoplasm and sporadically in the myelinized axons.     

Compositional equivalency of Cry1F corn event TC6275 and conventional corn (Zea mays L.)

Maize (Zea mays L.) plants have been transformed to express a Cry1F insecticidal crystal protein originally isolated from Bacillus thuringiensis Berliner. This protein controls lepidopteran pests of maize, including the European corn borer, Ostrinia nubilalis (Hübner). As part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. This analysis is designed to detect unintended changes in the nutrient and antinutrient content of the raw commodities produced by the crop due to the insertion of the genes into the genomic DNA of the plant (pleotropic effects). Samples of transgenic and nontransgenic maize forage and grain were collected from six field sites located in the U.S. and Canada. Forage samples were analyzed for proximates and minerals, and grain was further analyzed for fatty acids, amino acids, vitamins, secondary metabolites, and antinutrients. Results demonstrated that maize expressing the Cry1F protein was equivalent to nontransgenic maize with respect to these important components. Comparison of the variability within the nontransgenic and transgenic hybrid, as compared to composition values reported in the literature, suggest that factors other than transgenes may contribute more substantially to the composition of crops.     

Sternothyroideus Tenectomy Combination Surgery: Treatment Outcome in 95 Thoroughbred Racehorses (1996–2006)

This retrospective case series reports on the clinical experiences of a group of Thoroughbred racehorses in training that were treated surgically for intermittent dorsal displacement of the soft palate (DDSP) using sternothyroideus tenectomy in combination with soft palate surgery. The 95 horses included in the study were Thoroughbred racehorses in training referred for surgical treatment of intermittent DDSP over a 10-year period. Return to racing was 94% (89/95). Total earnings increased for up to three starts before and after surgery in 65% of horses (62/95, P= .0006). Of the 58 horses that raced in three or more races before and after surgery, 71% (41/58) improved their total earnings. Mean days to first start were 106 days. Performance index improved in 64% of these horses (37/58). Sixty of the 95 horses (63%) raced in six or more races after surgery. Sternothyroideus tenectomy combination surgery had a good prognosis for improving earnings and performance index after surgery in this group of horses that were treated for a working diagnosis of intermittent DDSP.     

Sperm nuclear protamines: A checkpoint to control sperm chromatin quality

Protamines are nuclear proteins which are specifically expressed in haploid male germ cells. Their replacement of histones and binding to DNA is followed by chromatin hypercondensation that protects DNA from negative influences by environmental factors. Mammalian sperm contain two types of protamines: PRM1 and PRM2. While the proportion of the two protamines is highly variable between different species, abnormal ratios within a species are known to be associated with male subfertility. Therefore, it is more than likely that correct protamine expression represents a kind of chromatin checkpoint during sperm development rendering protamines as suitable biomarkers for the estimation of sperm quality. This review presents an overview of our current knowledge on protamines comparing gene and protein structures between different mammalian species with particular consideration given to man, mouse and stallion. At last, recent insights into the possible role of inherited sperm histones for early embryo development are provided.     

Rapid and Differential Proliferation of the Ty3-Gypsy LTR Retrotransposon Atlantys in the Genus Oryza

Here, we present the results of a comprehensive study of the distribution, evolution, heterogeneity, and phylogenetic relationships of the Ty3-Gypsy Atlantys long terminal repeat retrotransposable element family in Oryza. Atlantys element-related sequences make up a significant fraction of the genomes of species from the Officinalis complex as well as the Oryza ridleyi and O. granulata genomes. The proliferation of Atlantys elements, in many cases, took place after respective speciation events occurred. Most of the retrotranspositional events occurred within the last three million years. Atlantys is an ancient and ubiquitous component of the genus Oryza and has made significant contributions to genome size variation across the genus. Its structure is unusual when compared to other Ty3-Gypsy elements and its proliferation in the different Oryza species has been rapid and differential.