Outbreak of Salmonella Dublin-associated abortion in Danish fur farms

Outbreaks of Salmonella Dublin infections were recorded in 25 Danish mink and fox farms. All farms suffered extensive disease problems; clinical and pathological observations included abortion, stillbirths, necrotizing endometritis, and increased mortality. By genotyping with pulsed-field gel electrophoresis and amplified fragment length polymorphism, all isolates of S. Dublin had indistinguishable patterns. The outbreaks took place during April and May, around the time of whelping. During this period, mink are particularly susceptible to Salmonella infections. All affected farms were served by the same feed factory and it was concluded that a batch of contaminated feed was responsible for the outbreaks, although repeated culture of feed samples collected during the same period were negative. No other likely source could be identified. The results emphasize the importance of strict hygiene measures at feed factories and the proper use of ingredients of known Salmonella status, in particular during the whelping season. Infected mink farms did not have a higher risk of outbreak of salmonellosis in the year following the outbreak.     

Phytochemicals and dietary fiber components in rye varieties in the HEALTHGRAIN Diversity Screen

Ten rye varieties grown in one location were analyzed for their contents of dietary fiber (arabinoxylan and beta-glucan) and phytochemicals (folate, tocols, phenolic acids, alkylresorcinols, and sterols). The varieties included old and modern varieties from five European countries. Significant differences were observed in the contents of all phytochemicals in whole grains and in the fiber contents in the flour and bran. The old French varieties Haute Loire and Queyras had high contents of most phytochemicals, whereas the Polish varieties Dankowskie-Zlote and Warko were relatively poor in phytochemicals. The varieties with a high content of folate tended to have low alkylresorcinol contents and vice versa. Furthermore, high contents of arabinoxylans were associated with high contents in tocols and sterols. The 10 selected rye samples comprising old populations and old and modern varieties from different ecological regions of Europe demonstrate high natural variation in their composition and show that landraces and old populations are useful genetic resources for plant breeding. The contents of single phytochemicals can likely be affected by breeding, and they may be adjusted by the right selection of genotype.     

Effect of genotypic,meteorological and agronomic factors on the gluten index of winter durum wheat

The determination of the gluten index is a widely used method for analysing the gluten strength of bread wheat and spring durum wheat genotypes. The present work was carried out to study the effect of the genotype, meteorological factors (temperature, precipitation and number of days with T_max ≥ 30 °C) and agronomic treatments (N fertilisation and plant protection) on the gluten index of winter durum wheat varieties and breeding lines. The results indicated that the gluten index had little dependence on the environment, being determined to the greatest extent by the genotype. Compared with varieties having weak gluten, those with a strong gluten matrix responded less sensitively to changes in environmental conditions. Among the meteorological factors, high temperature at the end of the grain-filling period caused the greatest reduction in the mean gluten index of three varieties (R ² = 0.462), while the fertiliser was found to be a significant factor affecting the gluten strength of winter durum wheat varieties. Using selection based on the gluten index, the gluten strength of winter durum wheat lines can be improved sufficiently to make them competitive with high quality spring varieties.     

The HEALTHGRAIN Cereal Diversity Screen: concept, results, and prospects

One hundred and fifty bread wheat lines and 50 other lines of small-grain cereals (spelt, durum wheat, Triticum monococcum, Triticum dicoccum, oats, rye, and barley) were selected for diversity in their geographical origin, age, and characteristics. They were grown on a single site in Hungary in 2004-2005, harvested, milled, and analyzed for a range of phytochemicals (tocols, sterols, phenolic acids, folates, alkylresorcinols) and fiber components that are considered to have health benefits. Detailed analyses of these components in the different species are reported in a series of accompanying papers. The present paper discusses the comparative levels of the bioactive components in the different species, showing differences in both ranges and mean amounts. Furthermore, detailed comparisons of the bread wheat lines show that it is possible to identify lines in which high levels of phytochemicals and dietary fiber components are combined with good yield and processing quality. This means that commercially competitive lines with high levels of bioactive components are a realistic goal for plant breeders.     

Development and characterization of wheat lines with increased levels of arabinoxylan

Improving the nutritional quality and health benefits of food has been of increasing interest globally over the last decade. Staple cereal foods are the major sources of dietary fiber and a recent study identified the Chinese wheat cultivar Yumai-34 as having unusually high levels of water-extractable arabinoxylan (WE-AX) and total arabinoxylan (TOT-AX) in flour. Crosses were therefore made between this variety and three Central European varieties (Lupus, Mv-Mambo, Ukrainka) and the physical properties (test weight, thousand-kernel weight, flour yield, kernel hardness), composition (protein, gluten, WEAX, total AX) and processing quality (gluten index, Zeleny sedimentation, Farinograph parameters) of the grain were compared for thirty-one breeding lines (F₇–F₉) and the four parents in a 3-year field experiment (2013–2015). Increases of 0.5% in the WE-AX content and 1% in the content of total AX content of the flour were achieved, with an improvement in dough properties. The thousand-kernel weight, protein content, gluten content, Zeleny sedimentation and water absorption of the flour also increased in many lines, while three of the lines had yields that were competitive with the official control varieties, making them suitable for registration.     

Wnt induces LRP6 signalosomes and promotes dishevelled-dependent LRP6 phosphorylation

Multiple signaling pathways, including Wnt signaling, participate in animal development, stem cell biology, and human cancer. Although many components of the Wnt pathway have been identified, unresolved questions remain as to the mechanism by which Wnt binding to its receptors Frizzled and Low-density lipoprotein receptor-related protein 6 (LRP6) triggers downstream signaling events. With live imaging of vertebrate cells, we show that Wnt treatment quickly induces plasma membrane-associated LRP6 aggregates. LRP6 aggregates are phosphorylated and can be detergent-solubilized as ribosome-sized multiprotein complexes. Phospho-LRP6 aggregates contain Wnt-pathway components but no common vesicular traffic markers except caveolin. The scaffold protein Dishevelled (Dvl) is required for LRP6 phosphorylation and aggregation. We propose that Wnts induce coclustering of receptors and Dvl in LRP6-signalosomes, which in turn triggers LRP6 phosphorylation to promote Axin recruitment and beta-catenin stabilization.     

Effects of genotype and environment on the contents of betaine, choline, and trigonelline in cereal grains

This study examined the environmental and genetic variation in methyl donor contents and compositions of 200 cereal genotypes. Glycine betaine, choline, and trigonelline contents were determined by (1)H NMR, and significant differences were observed between cereal types (G) and across harvesting years and growing locations (E). Glycine betaine was the most abundant methyl donor in all of the 200 lines grown on a single site, and concentrations ranged from 0.43 ± 0.09 mg/g dm in oats to 2.57 ± 0.25 mg/g dm in diploid Einkorn varieties. In bread wheat genotypes there was a 3-fold difference in glycine betaine content. Choline contents, in the same lines, were substantially lower, and mean concentrations ranged from 0.17 mg/g dm in oats to 0.27 mg/g dm in durum wheat. Trigonelline was by far the least abundant of the methyl donors studied. Despite this, however, there were large differences between cereal types. Twenty-six wheat genotypes were grown in additional years at four European locations. The average glycine betaine content was highest in grains grown in Hungary and lowest in those grown in the United Kingdom. Across the six environments, there was a 3.8-fold difference in glycine betaine content. Glycine betaine levels, although moderately heritable (0.36), were found to be the most susceptible to the environmental conditions. Free choline concentrations were less variable across genotypes, but heritability of this component was the lowest of all methyl donor components (0.25) and showed a high G × E interaction. Trigonelline showed the most variation due to genotype. Heritability of this metabolite was the highest (0.59), but given that it is at a very low concentration in wheat, it is probably not attractive to plant breeders.     

Plasma somatolactin levels in coho salmon (Oncorhynchus kisutch) during smoltification and sexual maturation

Somatolactin (SL) is a novel pituitary hormone recently characterized in several fish species. Structural analyses have shown that SL belongs to the growth hormone/prolactin family, and that it is a highly conserved protein. SL is synthesized by the periodic acid/Schiff-positive cells in the pars intermedia, but has an as yet unidentified function(s). We have recently developed a homologous radioimmunoassay for coho salmon SL and measured plasma levels of SL during two stages of the coho salmon life cycle, smoltification and sexual maturation. During smoltification, plasma levels of SL changed almost in parallel with plasma levels of thyroxine; levels increased as morphological indices of smoltification appeared and decreased as smoltification was completed. Following this period, SL levels remained low until the spring prior to spawning. In a separate study, plasma levels of SL were measured in sexually maturing coho salmon that remained in fresh water throughout their life cycle. During the year of sexual maturation, plasma levels of SL gradually increased from the spring onward, reaching peak levels at the time of spawning in November and December. These data are similar to those previously reported for sexually maturing coho salmon that were maintained in seawater prior to spawning (Rand-Weaver et al. 1992). Therefore, increases in plasma SL levels occurred in sexually maturing fish irrespective of whether they were maintained in fresh water or seawater. Peak levels at spawning were higher than those observed during smoltification. Possible roles for SL in metabolism and reproduction are discussed.     

Immunoreactive somatolactin cells in the pituitary of young,migrating, spawning and spent chinook salmon,Oncorhynchus tshawytscha

Immunocytochemical techniques using an antiserum to cod somatolactin (SL) demonstrated the presence of SL cells in the intermediate lobe of the pituitary in Oncorhynchus tshawytscha. The cells were small in yearling fish. Two groups of maturing fish were studied. In the spring run salmon collected in April and May during the upstream migration, the SL cells appeared stimulated. In September, during spawning, SL cell stimulation was maximal with indices of hypertrophy and degranulation often more marked in females than in males. In the other group, salmon of the fall run collected in the Pacific Ocean in August had well developed gonads, large gonadotropes and abundant SL cells. In spawning salmon (September) the SL cells were stimulated, mainly in females. However, the final stimulation was less intense than in spring run spawning fish. The SL cells were smaller, without evident granule release, but still abundant in spent salmon of the fall run caught at the end of November. Various factors (time spent in rivers before spawning, starvation, decalcification, stress, hypothalamic influences) were considered which might explain differences between spring and fall run salmon. These observations suggest that SL may play a role in the control of gonadal maturation in chinook salmon as it may also do in sockeye and chum salmon previously studied, and that SL cells may be sensitive to the ambient salinity.