Gc X and Gc Y revealed by immunofixation electrophoresis

Summary Immunofixation electrophoresis is used to define two variants in the Gc system: Gc X and Gc Y. Gc X has one band with a mobility between Gc 1-1 and Gc 2-2 while Gc Y has two bands migrating faster than the cathodal band of Gc 1.     

Nitrogen fixation and biomass production in symbioses between Alnus incana and Frankia strains with different hydrogen metabolism

Three different strains of Frankia , the pure cultures AvcI1 and CpI1 and a local strain (crushed nodule inoculum), were compared in symbiosis with one clone of Alnus incana (L.) Moench. Hydrogen metabolism, nitrogenase (EC 1.7.99.2) activity and relative efficiency of nitrogenase were studied as well as growth and nitrogen content of the plants. The local Frankia strain showed no measurable hydrogen uptake but high H₂-evolution. No H₂-evolution was detected in Frankia AvcI1 because of its hydrogenase activity. CpI1 also had hydrogenase, although only a very small H₂-evolution was detected at the end of the growth period. Hydrogenase activity was detected both in pure cultures and nodule homogenates of CpI1 and AvcI1. Growth, biomass production and nitrogen content were highest in alders inoculated with Frankia AvcI1 while the lowest values were found for alders living in symbiosis with the local Frankia strain. The presence of hydrogenase in Frankia seemed to be benefical for growth and biomass production in the alders. However, the strains also differed with respect to spore formation. The local strain, but not AvcI1 and CpI1, formed spores in the root nodules.     

Mapping of quantitative adult plant field resistance to leaf rust and stripe rust in two European winter wheat populations reveals co-location of three QTL conferring resistance to both rust pathogens

Key message

We detected several, most likely novel QTL for adult plant resistance to rusts. Notably three QTL improved resistance to leaf rust and stripe rust simultaneously indicating broad spectrum resistance QTL.

Abstract

The rusts of wheat (Puccinia spp.) are destructive fungal wheat diseases. The deployment of resistant cultivars plays a central role in integrated rust disease management. Durability of resistance would be preferred, but is difficult to analyse. The Austrian winter wheat cultivar Capo was released in the 1989 and grown on a large acreage during more than two decades and maintained a good level of quantitative leaf rust and stripe rust resistance. Two bi-parental mapping populations: Capo × Arina and Capo × Furore were tested in multiple environments for severity of leaf rust and stripe rust at the adult plant stage in replicated field experiments. Quantitative trait loci associated with leaf rust and stripe rust severity were mapped using DArT and SSR markers. Five QTL were detected in multiple environments associated with resistance to leaf rust designated as QLr.ifa-2AL, QLr.ifa-2BL, QLr.ifa-2BS, QLr.ifa-3BS, and QLr.ifa-5BL, and five for resistance to stripe rust QYr.ifa-2AL, QYr.ifa-2BL, QYr.ifa-3AS, QYr.ifa-3BS, and QYr.ifa-5A. For all QTL apart from two (QYr.ifa-3AS, QLr.ifa-5BL) Capo contributed the resistance improving allele. The leaf rust and stripe rust resistance QTL on 2AL, 2BL and 3BS mapped to the same chromosome positions, indicating either closely linked genes or pleiotropic gene action. These three multiple disease resistance QTL (QLr.ifa-2AL/QYr.ifa-2AL, QLr.ifa.2BL/QYr.ifa-2BL, QLr.ifa-3BS/QYr.ifa.3BS) potentially contribute novel resistance sources for stripe rust and leaf rust. The long-lasting resistance of Capo apparently rests upon a combination of several genes. The described germplasm, QTL and markers are applicable for simultaneous resistance improvement against leaf rust and stripe rust.     

Plus- and Minus-End Directed Microtubule Motors Bind Simultaneously to Herpes Simplex Virus Capsids Using Different Inner Tegument Structures

Many viruses depend on host microtubule motors to reach their destined intracellular location. Viral particles of neurotropic alphaherpesviruses such as herpes simplex virus 1 (HSV1) show bidirectional transport towards the cell center as well as the periphery, indicating that they utilize microtubule motors of opposing directionality. To understand the mechanisms of specific motor recruitment, it is necessary to characterize the molecular composition of such motile viral structures. We have generated HSV1 capsids with different surface features without impairing their overall architecture, and show that in a mammalian cell-free system the microtubule motors dynein and kinesin-1 and the dynein cofactor dynactin could interact directly with capsids independent of other host factors. The capsid composition and surface was analyzed with respect to 23 structural proteins that are potentially exposed to the cytosol during virus assembly or cell entry. Many of these proteins belong to the tegument, the hallmark of all herpesviruses located between the capsid and the viral envelope. Using immunoblots, quantitative mass spectrometry and quantitative immunoelectron microscopy, we show that capsids exposing inner tegument proteins such as pUS3, pUL36, pUL37, ICP0, pUL14, pUL16, and pUL21 recruited dynein, dynactin, kinesin-1 and kinesin-2. In contrast, neither untegumented capsids exposing VP5, VP26, pUL17 and pUL25 nor capsids covered by outer tegument proteins such as vhs, pUL11, ICP4, ICP34.5, VP11/12, VP13/14, VP16, VP22 or pUS11 bound microtubule motors. Our data suggest that HSV1 uses different structural features of the inner tegument to recruit dynein or kinesin-1. Individual capsids simultaneously accommodated motors of opposing directionality as well as several copies of the same motor. Thus, these associated motors either engage in a tug-of-war or their activities are coordinately regulated to achieve net transport either to the nucleus during cell entry or to cytoplasmic membranes for envelopment during assembly.     

Acidic elements in histamine H3 receptor antagonists

Antagonists of the human histamine H₃ receptor (hH₃R) often contain a second basic moiety, which is well known to boost affinity on this histamine receptor subtype. Here, we prepared compounds with acidic moieties of different pK_a values to figure out that the hH₃R tolerates these functionalities when added to a common pharmacophore blueprint. Depending on the acidic, electronic and steric features the designed ligands showed hH₃R affinities in the nanomolar concentration range. Additionally, selected ligands were tested but failed as dual acting hH₃R/hPPAR (human peroxisome proliferator-activated receptor) ligands.     

Maternal behavior in pigs

When sows kept under commercial conditions were put into crates in the early 1960s, the neuro-endocrine regulation of the maternal behavior in these domestic animals was disputed. Thus, the study of sow maternal behavior intensified and today a significant body of knowledge has accumulated to support the hormonal regulation of sow maternal behavior. The onset of nest building is associated with a periparturient decline in progesterone, an increase in prolactin and a major rise in plasma concentrations of PGF2alpha the day before parturition. Some nest building behaviors, such as pawing and gathering straw, have been found to correlate with changes in the levels of progesterone, prolactin and somatostatin. The duration of the birth process correlates negatively with peripheral oxytocin levels. During lactation, the stimuli from the piglets affect the release of several hormones which not only regulate the let down of milk but also sow metabolism and mammary milk production. The sow's nursing behavior ensures an even distribution of milk to her piglets. The piglets suckling behavior, in turn, is mainly a way to communicate their individual nutritional needs.     

Cytochrome P450 systems--biological variations of electron transport chains

Cytochromes P450 (P450) are hemoproteins encoded by a superfamily of genes nearly ubiquitously distributed in different organisms from all biological kingdoms. The reactions carried out by P450s are extremely diverse and contribute to the biotransformation of drugs, the bioconversion of xenobiotics, the bioactivation of chemical carcinogens, the biosynthesis of physiologically important compounds such as steroids, fatty acids, eicosanoids, fat-soluble vitamins and bile acids, the conversion of alkanes, terpenes and aromatic compounds as well as the degradation of herbicides and insecticides. Cytochromes P450 belong to the group of external monooxygenases and thus receive the necessary electrons for oxygen cleavage and substrate hydroxylation from different redox partners. The classical as well as the recently discovered P450 redox systems are compiled in this paper and classified according to their composition.