DNA markers linked to a T10 loose smut resistance gene in wheat (Triticum aestivum L.).

Screening for loose smut resistance in wheat is difficult. Selecting lines with DNA markers linked to loose smut resistance would be more reliable and less costly. Molecular markers linked to a race T10 loose smut resistance gene were identified using a F6 single seed descent segregating population. A RAPD marker and a RFLP marker were located on opposite flanks of the resistance gene and were shown to be loosely linked. The RAPD marker was converted to a user friendly polymorphic SCAR marker that represented a single genetically defined locus in hexaploid wheat. Using these two bracketing markers simultaneously, the error rate for T10 resistance selection due to crossing-over was reduced to 4%. These markers can be used for a faster and more reliable selection of T10 resistant plants than previous conventional loose smut ratings.     

Chinese hamster ovary cells produce sufficient recombinant insulin-like growth factor I to support growth in serum-free medium. Serum-free growth of IGF-I-producing CHO cells

Insulin-like growth factor I has similar mitogenic effects to insulin, a growth factor required by most cells in culture, and it can replace insulin in serum-free formulations for some cells. Chinese Hamster Ovary cells grow well in serum-free medium with insulin and transferrin as the only exogenous growth factors. An alternative approach to addition of exogenous growth factors to serum-free medium is transfection of host cells with growth factor-encoding genes, permitting autocrine growth. Taking this approach, we constructed an IGF-I heterologous gene driven by the cytomegalovirus promoter, introduced it into Chinese Hamster Ovary cells and examined the growth characteristics of Insulin-like growth factor I-expressing clonal cells in the absence of the exogenous factor. The transfected cells secreted up to 500 ng/10⁶ cells/day of mature Insulin-like growth factor I into the conditioned medium and as a result they grew autonomously in serum-free medium containing transferrin as the only added growth factor. This growth-stimulating effect, observed under both small and large scale culture conditions, was maximal since no further improvement was observed in the presence of exogenous insulin. This revised version was published online in July 2006 with corrections to the Cover Date.     

Developmental expression of hexokinase 1 and 3 in rats

 Mammalian hexokinase types one and three (HK1 and HK3) are 100 kDa isozymes that phosphorylate glucose to glucose-6-phosphate. HK1 is present in most tissues but is especially prominent in brain and kidney. HK3 is less well studied, but may be most prominent in the spleen and lymphocytes. In this study, we determined the ontogeny of the expression of these isoforms in the rat. Using immunohistochemistry, we identified HK1 and HK3 immunoreactivity in the brain, heart, kidney, liver, skeletal muscle and spleen from gestational day 14 (E14) to 45 days after birth (P45). With the exception of the liver and spleen, we observed a similar age- and cell-dependent staining pattern for both isoforms in all organs studied. The brain and spleen were analyzed in more detail to identify specific regions of immunoreactivity during maturation. A transient expression of HK1 and HK3 was noted in the cell bodies of mature neurons, including layers V and VI of the cerebral cortex and the cerebellar Purkinje cells followed by localization to the white matter of the cerebrum and cerebellum. In the spleen, HK3 immunoreactivity was detected postnatally and appeared to track with the infiltration of B cells. Our demonstration of changing patterns of immunoreactivity for HK1 and HK3 in fetal and postnatal organs suggests that these HK isoforms are involved the process of development. We speculate that HK1 and HK3 share a complex interaction during development of these organs and regulate glucose metabolism at multiple levels during development. Accepted: 16 May 1997     

Guidelines for drug donations.

Drug donations are usually given in response to acute emergencies, but they can also be part of development aid. Donations may be given directly by governments, by non-governmental organisations, as corporate donations (direct or through private voluntary organisations), or as private donations to single health facilities. Although there are legitimate differences between these donations, basic rules should apply to them all. This common core of "good donation practice" is the basis for new guidelines which have recently been issued by the World Health Organisation after consultation with all relevant United Nations agencies, the Red Cross, and other major international agencies active in humanitarian emergency relief. This article summarises the need for such guidelines, the development process, the core principles, and the guidelines themselves and gives practical advice to recipients and donor agencies.     

Marine biodiversity: patterns, threats and conservation needs

Marine biodiversity is higher in benthic rather than pelagic systems, and in coasts rather than the open ocean since there is a greater range of habitats near the coast. The highest species diversity occurs in the Indonesian archipelago and decreases radially from there. The terrestrial pattern of increasing diversity from poles to tropics occurs from the Arctic to the tropics but does not seem to occur in the southern hemisphere where diversity is high at high latitides. Losses of marine diversity are highest in coastal areas largely as a result of conflicting uses of coastal habitats. The best way to conserve marine diversity is to conserve habitat and landscape diversity in the coastal area. Marine protected areas are only a part of the conservation strategy needed. It is suggested that a framework for coastal conservation is integrated coastal area management where one of the primary goals is sustainable use of coastal biodiversity.     

Structural studies on membrane-embedded influenza hemagglutinin and its fragments.

The mechanism of influenza virus hemagglutinin (HA)-mediated membrane fusion has been inferred in part from studies examining pH-induced structural changes in soluble HA derivatives lacking the viral membrane anchor and, sometimes, the fusion peptide (the C- and N-terminal residues of the HA2 chain, respectively). To reconcile structure-based mechanisms of HA-mediated membrane fusion with structural implications of functional studies performed on membrane-embedded HA, we have undertaken attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic analyses of membrane-embedded HA (strain X:31) and its fragments reconstituted into supported lipid bilayers. The fragments correspond to proteolytic products with the majority of the HA1 chain and, in some cases, the fusion peptide removed (THA2 and THA2F-, respectively). In combination with R18 fluorescence dequenching to monitor the functional implications of HA1 subunit removal, we have assessed the influence of pH and target membrane presentation on the secondary structures, orientations relative to the membrane, and dynamics of these molecules. We find that X:31 HA is more tilted towards the plane of the membrane under fusion than under resting conditions, that the fitting of HA depends on the presence of the HA1 chain, that the residues connecting the membrane-inserted fusion peptide with the crystallographically determined coiled coil probably adopt an alpha-helical conformation, and that several changes in the secondary structure and the amide H/D exchange kinetics occur as a result of acidification and target membrane presentation, which can be interpreted as small changes and a release of strain in the static and dynamic structure of membrane-bound HA. THA2 mediatcs fusion, but less efficiently and with less pH-selectivity than HA.     

Model‐specification uncertainty in future forest pest outbreak

Climate change will modify forest pest outbreak characteristics, although there are disagreements regarding the specifics of these changes. A large part of this variability may be attributed to model specifications. As a case study, we developed a consensus model predicting spruce budworm (SBW, Choristoneura fumiferana [Clem.]) outbreak duration using two different predictor data sets and six different correlative methods. The model was used to project outbreak duration and the uncertainty associated with using different data sets and correlative methods (=model‐specification uncertainty) for 2011–2040, 2041–2070 and 2071–2100, according to three forcing scenarios (RCP 2.6, RCP 4.5 and RCP 8.5). The consensus model showed very high explanatory power and low bias. The model projected a more important northward shift and decrease in outbreak duration under the RCP 8.5 scenario. However, variation in single‐model projections increases with time, making future projections highly uncertain. Notably, the magnitude of the shifts in northward expansion, overall outbreak duration and the patterns of outbreaks duration at the southern edge were highly variable according to the predictor data set and correlative method used. We also demonstrated that variation in forcing scenarios contributed only slightly to the uncertainty of model projections compared with the two sources of model‐specification uncertainty. Our approach helped to quantify model‐specification uncertainty in future forest pest outbreak characteristics. It may contribute to sounder decision‐making by acknowledging the limits of the projections and help to identify areas where model‐specification uncertainty is high. As such, we further stress that this uncertainty should be strongly considered when making forest management plans, notably by adopting adaptive management strategies so as to reduce future risks.