Genetic analysis of preharvest sprouting in a six-row barley cross

Preharvest sprouting (PHS) can be a problem in barley (Hordeum vulgare L.) especially malting barley, since rapid, uniform, and complete germination are critical. Information has been gained by studying the genetics of dormancy (measured as germination percentage, GP). The objective of this study was to determine if the quantitative trait loci (QTLs) discovered in previous research on dormancy are related to PHS. PHS was measured as sprout score (SSc) based on visual sprouting in mist chamber-treated spikes and as alpha-amylase activity (AA) in kernels taken from mist chamber-treated spikes that showed little or no visible sprouting. GP was also measured. All traits were measured at 0 and 14 days after physiological maturity. Evaluation of the spring six-row cross, Steptoe (dormant)/Morex (non-dormant) doubled haploid mapping population grown in greenhouse and field environments revealed QTL regions for SSc, AA, and GP on five, four, and six of the seven barley chromosomes, respectively. In total, seven and eight regions on five and six chromosomes had effects ranging from 4 to 31% and 3 to 39% on PHS and dormancy, respectively. One chromosome 3H and three chromosome 5H QTLs had the greatest effects. All PHS QTLs coincide with known dormancy QTLs, but some QTLs appear to be more important for PHS than for dormancy. Key QTLs identified should benefit breeding of barley for a suitable balance between PHS and dormancy.     

Genetic and physical mapping of a high recombination region on chromosome 7H(1) in barley

Approaches utilizing microlinearity between related species allow for the identification of syntenous regions and orthologous genes. Within the barley Chromosome 7H(1) is a region of high recombination flanked by molecular markers cMWG703 and MWG836. We present the constructed physical contigs linked to molecular markers across this region using bacterial artificial chromosomes (BAC) from the cultivar Morex. Barley expressed sequence tags (EST), identified by homology to rice chromosome 6 between the rice molecular markers C425A and S1434, corresponded to the barley syntenous region of Chromosome 7H(1) Bins 2–5 between molecular markers cMWG703-MWG836. Two hundred and thirteen ESTs were genetically mapped yielding 267 loci of which 101 were within the target high recombination region while 166 loci mapped elsewhere. The 101 loci were joined by 43 other genetic markers resulting in a highly saturated genetic map. In order to develop a physical map of the region, ESTs and all other molecular markers were used to identify Morex BAC clones. Seventy-four BAC contigs were formed containing 2–102 clones each with an average of 19 and a median of 13 BAC clones per contig. Comparison of the BAC contigs, generated here, with the Barley Physical Mapping Database contigs, resulted in additional overlaps and a reduction of the contig number to 56. Within cMWG703-MWG836 are 24 agriculturally important traits including the seedling spot blotch resistance locus, Rcs5. Genetic and physical analysis of this region and comparison to rice indicated an inversion distal of the Rcs5 locus. Three BAC clone contigs spanning the Rcs5 locus were identified. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Metabolic stress boosts humoral responses in vivo independently of inflammasome and inflammatory reaction

Adjuvant formulations boost humoral responses by acting through several, yet incompletely elucidated pathways. In this study, we show that oligomycin or 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) enhances Ab production when coinjected with T cell-dependent Ags. Oligomycin and AICAR lead to intracellular ATP reduction, suggesting that metabolic stress could be sensed by immune cells and leads to increased humoral responses. AICAR promotes IL-4 and IL-21 by naive Th cells but does not affect dendritic cell activation/maturation in vitro or in vivo. Accordingly, the adjuvant effect of AICAR or oligomycin does not require MyD88 or caspase-1 expression in vivo. Because AICAR is well tolerated in humans, this compound could represent a novel and safe adjuvant promoting humoral responses in vivo with a minimal reactogenicity.     

Mosaic RNA Phage VLPs Carrying Domain III of the West Nile Virus E Protein

The virus-neutralising domain III (DIII) of the West Nile virus glycoprotein E was exposed on the surface of RNA phage AP205 virus-like particles (VLPs) in mosaic form. For this purpose, a 111 amino acid sequence of DIII was added via amber or opal termination codons to the C-terminus of the AP205 coat protein, and mosaic AP205-DIII VLPs were generated by cultivation in amber- or opal-suppressing Escherichia coli strains. After extensive purification to 95 % homogeneity, mosaic AP205-DIII VLPs retained up to 11–16 % monomers carrying DIII domains. The DIII domains appeared on the VLP surface because they were fully accessible to anti-DIII antibodies. Immunisation of BALB/c mice with AP205-DIII VLPs resulted in the induction of specific anti-DIII antibodies, of which the level was comparable to that of the anti-AP205 antibodies generated against the VLP carrier. The AP205-DIII-induced anti-DIII response was represented by a significant fraction of IgG2 isotype antibodies, in contrast to parallel immunisation with the DIII oligopeptide, which failed to induce IgG2 isotype antibodies. Formulation of AP-205-DIII VLPs in alum adjuvant stimulated the level of the anti-DIII response, but did not alter the fraction of IgG2 isotype antibodies. Mosaic AP205-DIII VLPs could be regarded as a promising prototype of a putative West Nile vaccine.     

The Rise of Partisanship and Super-Cooperators in the U.S. House of Representatives

It is widely reported that partisanship in the United States Congress is at an historic high. Given that individuals are persuaded to follow party lines while having the opportunity and incentives to collaborate with members of the opposite party, our goal is to measure the extent to which legislators tend to form ideological relationships with members of the opposite party. We quantify the level of cooperation, or lack thereof, between Democrat and Republican Party members in the U.S. House of Representatives from 1949–2012. We define a network of over 5 million pairs of representatives, and compare the mutual agreement rates on legislative decisions between two distinct types of pairs: those from the same party and those formed of members from different parties. We find that despite short-term fluctuations, partisanship or non-cooperation in the U.S. Congress has been increasing exponentially for over 60 years with no sign of abating or reversing. Yet, a group of representatives continue to cooperate across party lines despite growing partisanship.     

Myocardial infarct death and temperature in Auckland,New Zealand

Daily myocardial infarct deaths for Auckland (36° 51S, 20 m above sea-level) show an increase in mortality rate with decreasing temperatures over the entire thermal range. Parallel studies in Brisbane and Montreal predicted a minimum death temperature between 21 and 24° C, but no such point was apparent. Lack of temperatures above 21° C, together with the small overall thermal range, is thought responsible.     

A hypothesis for thein vivo antioxidant action of salicyclic acid

This paper presents a new hypothesis for the physiological antioxidant action of salicylate. Current theories have focused on the radical scavenging nature of salicylate. This explanation may have limitations because it is unlikely that salicylate reaches the necessary concentrations to effectively prevent damage to cell components. We propose that salicylic acid decreases the flux of hydroxyl radicals through chelation, which causes a redox deactivation mechanism of iron Fenton reaction centers. This is due to voltammetric results which indicate that the iron-salicylate complex does not have the thermodynamic driving force to act as an effective Fenton reagent necessary for the production of damaging oxygen-containing radicals. Furthermore, despite the more facile thermodynamics associated with Fenton-type processes at acidic pH values, the complex maintains Fenton inactivity due to a pH-sensitive redox potential shift that follows asE _Fe[Sal] = 0.793 - (0.059 pH). This is important since inflammation sites are acidic relative to healthy tissue. This redox potential shift is unique to salicylates when compared with other common iron chelation agents such as EDTA. Further evidence for the lack of Fenton-type reactivity of the iron-salicylate complex is offered in the form of oxidation studies of calf thymus (CT) DNA by hydrogen peroxide. Salicylate prevents the iron-catalyzed oxidation of CT-DNA strands as indicated by the detection of the constituent bases by HPLC. However, salicylates were not able to prevent the copper-catalyzed oxidation of CT-DNA. These results are predicted by the cyclic voltammetry of copper-salicylate, which confirms that it is an effective Fenton-type catalyst, further adding to the proof that salicylate acts by redox deactivation of iron, not by hydroxyl radical scavenging. Finally, the iron-salicylate e.m.f. suggests that it may also act as a superoxide dismutase, which indicates another possible important antioxidant feature.     

Analysis of D2 d : a D-region class I gene

The mouse major histocompatibility complex is composed of several genes arranged into the K, D, Qa, and Tla regions. The D region of the BALB/c mouse includes genes D2 ^d , D3 ^d , and D4 ^d , in addition to H-2D ^d and H-2L ^d . We have determined the DNA sequence of the D2 ^d gene and compared it with the known sequences of several class I genes. The exon/intron structure of the D2 ^d gene is similar to other class I genes. It also contains similar 5 regulatory elements. A frameshift occurs in exon seven, resulting in a gene product with a truncated cytoplasmic tail. To examine the surface expression of the D2^d molecule, we generated an exon-shuffled construct containing the promoter and exons 1–3, encoding the signal peptide, 1, and 2 external domains of the D2 ^d gene linked to exons 4–8, encoding the 3, transmembrane and cytoplasmic domains, of the H-2D ^d gene. The construct was transfected into mouse L cells, and a protein was detected at the cell surface by a monoclonal antibody (mAb) specific for the 3 domain of H-2D^d, as well as by other class I-specific mAbs. Although D2^d is expressed at low levels, it may be a functional class I gene that most probably evolved from a Qa region gene.     

Survival of Microorganisms in a Rock Bed Under Conditions Simulating Solar Heat Storage

A laboratory-scale unit containing about 360 kg of washed river gravel was designed to [ill] the use of rocks for heat storage. The unit was operated under varying conditions of temperature, relative humidity, and the addition of volatile nutrients over a 4-month period. Effluent air and rock surfaces were monitored for the presence of microorganisms. After 2 weeks, virtually no microorganisms were detected in the effluent air except when dry soil or compost was added as the inoculum. A small number of heat-resistant bacteria, but no fungi, were found to survive on the rock surfaces. Microorganisms isolated were either sporeforming bacteria or actinomycetes closely resembling Thermoactinomyces vulgaris. Microbial colonization of rock beds used for solar heat storage does not appear likely under routine operation.     

Factors affecting anther culturability of recalcitrant barley genotypes

One major problem encountered with cereal anther culture is that some genotypes are low or non-responders to the technique. The objective of this study was to improve anther culture efficiency of recalcitrant barley (Hordeum vulgare L.) genotypes. Reciprocal F₁s between the two low responsive cultivars, Morex and Steptoe, were used. These were chosen because doubled haploids (DH) were required from these genotypes for the North American Barley Genome Mapping project. Ficoll 400 at 200 g l^–1 in the induction medium significantly increased green plant production compared to four other media formations containing different gelling/viscosity modifying agents. Cold pretreatment of donor spikes of 28 vs 14 d resulted in an increase in embryoid, total plant and green plant production. Anther culture response in these experiments was little influenced by donor plant growth conditions. Indole-3-acetic acid (1 mg l^–1) or 1-naphthaleneacetic acid (2 mg l^–1) in the induction medium did not affect anther culturability or plant regeneration. Based on this research, the negative genotypic effect for doubled haploid production could be diminished, which is desirable for practical application.Abbreviations BAP 6-benzylaminopurine - IAA Indole-3-acetic acid - LS Linsmaier & Skoog - NAA 1-naphthaleneacetic acid - DH doubled haploid