Folate in wheat genotypes in the HEALTHGRAIN Diversity Screen

As part of the diversity screen of the HEALTHGRAIN project, the total folate contents of bread wheat (130 winter and 20 spring wheat genotypes), durum wheat (10 genotypes), earlier cultivated diploid einkorn and tetraploid emmer wheat (5 genotypes of each), and spelt (5 genotypes), grown in the same location in a controlled manner, were determined by a microbiological assay. The total folate contents ranged from 364 to 774 ng/g of dm in winter wheat and from 323 to 741 ng/g of dm in spring wheat, thus showing a marked variation. The highest mean for total folate content was measured in the durum wheat genotypes, whereas the earlier cultivated diploid and tetraploid wheat genotypes and spelt were shown to possess comparable or even higher folate contents than bread wheat. HPLC analysis of selected genotypes showed that 5-formyltetrahydrofolate was the major vitamer. The data provide a basis for breeding wheat genotypes with improved folate content.     

Direct and indirect transmission of four Salmonella enterica serotypes in pigs

Background

Feed-borne spread of Salmonella spp. to pigs has been documented several times in recent years in Sweden. Experiences from the field suggest that feed-associated serotypes might be less transmittable and subsequently easier to eradicate from pig herds than other serotypes more commonly associated to pigs. Four Salmonella serotypes were selected for experimental studies in pigs in order to study transmissibility and compare possible differences between feed-assoociated (S Cubana and S Yoruba) and pig-associated serotypes (S Derby and S Typhimurium).

Methods

Direct contact transmission was studied in four groups of pigs formed by six 10-week-old salmonella negative pigs commingled with two fatteners excreting one of the four salmonella serotypes. Indirect transmission was studied by putting six 10-week-old salmonella negative pigs in each of four salmonella contaminated rooms. Each room had previously housed a group of pigs, excreting one of the four selected serotypes.All pigs were monitored for two weeks with respect to the faecal excretion of salmonella and the presence of serum antibodies. At the end of the trial, eight samples from inner tissues and organs were collected from each pig at necropsy.

Results

In the four direct transmission groups, one pig shed Salmonella (Cubana) at one occasion. At necropsy, S Typhimurium was isolated from one pig.In the indirect transmission groups, two pigs in the Yoruba room and one pig in each of the other rooms were excreting detectable levels of Salmonella once during the study period of two weeks. At necropsy, S Derby was isolated from one of six pigs in the Derby room and S Typhimurium was isolated from four of the six pigs in the Typhimurium room.No significant serological response could be detected in any of the 48 pigs.

Conclusions

These results show that all four selected serotypes were able to be transmitted in at least one of these field-like trials, but the transmission rate was low in all groups and no obvious differences between feed-associated and pig-associated serotypes in the transmission to naïve pigs and their subsequent faecal shedding were revealed. However, the post mortem results indicated a higher detection of S Typhimurium in the ileocecal lymph nodes of pigs introduced into a contaminated environment in comparison with the other three serotypes.     

Emulating membrane protein evolution by rational design

How do integral membrane proteins evolve in size and complexity? Using the small multidrug-resistance protein EmrE from Escherichia coli as a model, we experimentally demonstrated that the evolution of membrane proteins composed of two homologous but oppositely oriented domains can occur in a small number of steps: An original dual-topology protein evolves, through a gene-duplication event, to a heterodimer formed by two oppositely oriented monomers. This simple evolutionary pathway can explain the frequent occurrence of membrane proteins with an internal pseudo-two-fold symmetry axis in the plane of the membrane.     

The Genome sequence of the SARS-associated coronavirus

We sequenced the 29,751-base genome of the severe acute respiratory syndrome (SARS)-associated coronavirus known as the Tor2 isolate. The genome sequence reveals that this coronavirus is only moderately related to other known coronaviruses, including two human coronaviruses, HCoV-OC43 and HCoV-229E. Phylogenetic analysis of the predicted viral proteins indicates that the virus does not closely resemble any of the three previously known groups of coronaviruses. The genome sequence will aid in the diagnosis of SARS virus infection in humans and potential animal hosts (using polymerase chain reaction and immunological tests), in the development of antivirals (including neutralizing antibodies), and in the identification of putative epitopes for vaccine development.     

Molecular basis of proton motive force generation: structure of formate dehydrogenase-N

The structure of the membrane protein formate dehydrogenase-N (Fdn-N), a major component of Escherichia coli nitrate respiration, has been determined at 1.6 angstroms. The structure demonstrates 11 redox centers, including molybdopterin-guanine dinucleotides, five [4Fe-4S] clusters, two heme b groups, and a menaquinone analog. These redox centers are aligned in a single chain, which extends almost 90 angstroms through the enzyme. The menaquinone reduction site associated with a possible proton pathway was also characterized. This structure provides critical insights into the proton motive force generation by redox loop, a common mechanism among a wide range of respiratory enzymes.     

Tiller traits of spring cereals under tiller-depressing long day conditions

Long days partially depress tiller growth of spring cereals. In this study we characterised and quantified growing conditions and cultivar-induced variation in tiller traits and contribution of tillers to grain yield. Experiments were done at two locations in southern Finland, incorporating two nitrogen fertiliser application rates (80 and 120 kg N ha⁻¹) and 12 two-row barley (Hordeum vulgare L.), 10 six-row barley, ten oat (Avena sativa L.) and 11 wheat (Triticum aestivum L.) cultivars. Spring cereal species differed significantly in their tillering: two-row barley was superior compared with other spring cereals, with the highest number and growth capacity of tillers and head-bearing tillers. Grain yield produced by tillers was, however, always modest compared with that of main shoots, ranging from 13% and 15% in oat and wheat to 20% in six-row barley and 64% in two-row barley. Cultivar and growing condition-induced differences were marked in tiller traits, but tillers were never able to out-yield the main shoot. This is likely to be emphasised by standard use of high seeding rates. Tillers are dominated by the main shoot under long day conditions at high latitudes, and tiller yield potential remains clearly underutilised even under conditions favouring growth.     

Distribution of Arcellaceans (Testate Amoebae) in the Sediments of a Mine Water Impacted Bay of Lake Retunen, Finland

This study employs chemical fractionations of sedimentary metals and analyses of sediment arcellacean (thecamoebian) faunas to study the ecological effects of mining wastewaters in a boreal lake bay that receives metal-rich waters from a Cu mine. Sediment chemistry and arcellacean species compositions were analyzed from both surface sediment samples and a sediment profile to investigate spatial and temporal changes in mine water pollution and biota. Based on the results, geochemical gradients in the area are caused by dispersal and dilution of metal-rich, low-pH mine waters entering the lake; transport and focusing of fine grained metal precipitates and sulphate in the deep areas of the bay; increase in pH due to sulphate reduction and mobilization of redox-sensitive elements from deep water sites; and precipitation of the mobilized metals at shallower sites. Arcellacean species compositions change systematically with increasing distance from the source of pollution and species diversity as well as concentrations of tests in the samples increase as well. Fe:Mn ratio and adsorbed Al explained variation in surface sediment arcellaceans with statistical significance. Fe:Mn ratio is an indicator of the overall geochemical environment (Eh, pH), while the toxicity of Al in aquatic environments is well known. Changes in arcellacean species and geochemistry in the long core suggest that before the mine closure in 1983, mine waters differed in nature from the present acid drainage and metals such as Cu, Co, Zn and Ni may have affected arcellaceans at that time.     

Orosomucoid expression profiles in liver,adipose tissues and serum of lean and obese domestic pigs,Göttingen minipigs and Ossabaw minipigs

The acute phase protein orosomucoid (ORM) has anti-inflammatory and immunomodulatory effects, and may play an important role in the maintenance of metabolic homeostasis in obesity-induced low-grade inflammation. Even though the pig is a widely used model for obesity related metabolic symptoms, the expression of ORM has not yet been characterized in such pig models. The objective of this study was to investigate the expression of ORM1 mRNA in liver, visceral adipose tissue, subcutaneous adipose tissue (SAT) from the abdomen or retroperitoneal abdominal adipose tissue (RPAT) and SAT from the neck, as well as the serum concentration of ORM protein in three porcine obesity models; the domestic pig, Göttingen minipigs and Ossabaw minipigs.No changes in ORM1 mRNA expression were observed in obese pigs compared to lean pigs in the four types of tissues. However, obese Ossabaw minipigs, but none of the other breeds, showed significantly elevated ORM serum concentrations compared to their lean counterparts. Studies in humans have shown that the expression of ORM was unchanged in adipose tissue depots in obese humans with an increased serum concentration of ORM. Thus in this respect, obese Ossabaw minipigs behave more similarly to obese humans than the other two pig breeds investigated.