CD117‐ and vimentin‐positive telocytes in the bovine teat sphincter

Mastitis is a common economically relevant problem in dairy farming. As the major entry for pathogens is the papillary duct, one of the first defence mechanisms is the teat sphincter. This sphincter shows a rhythmic contractility of yet unknown origin. Searching for possible modulatory pacemaker cells, teat sphincters of eight cows were stained immunohistochemically with antibodies against CD117 and vimentin and evaluated microscopically for the presence of telocytes. CD117‐ and vimentin‐positive telocytes with telopodes were found in close contact with smooth muscle cells. Our findings present a first evidence of telocytes in the teat of bovines.     

Molecular evidence of Leishmania spp. in spider monkeys (Ateles geoffroyi) from The Tuxtlas Biosphere Reserve,Veracruz, Mexico

Veterinary Research Communications - The black-handed spider monkey (Ateles geoffroyi) is a platyrrhine primate distributed in southern Mexico, Central America, and part of South America. Two...     

Silicon concentration in spruce needles

The Si concentration in 1 year old needles from Norway spruce (P. abies) was determined at 39 sites within an area of 150 km². The sites had uniform elevation, precipitation and immission characteristics. The mean value was 1423 μg Si g^?1, and the coefficient of variation between sites was 29 %. There was no correlation of Si concentration in needles with soil pH in the range of pH 3.5 to 7.6, but significant negative correlations with soil organic matter concentration and with the effective cation exchange capacity were found. Silicon in needles correlated positively with Al, La, and Fe in needles, but showed no correlation with 20 other elements. The seasonal variation of Si concentration in needles showed a nonuniform increase with time. The seasonal changes of Si were similar to those of Ca. The investigation of 4 successive needle age classes, however, showed a strictly linear increase of the Si concentrations.     

Mycological and histological investigations of Fraxinus excelsior nursery saplings naturally infected by Chalara fraxinea

Ash dieback is an emerging disease of Fraxinus excelsior in Germany. To date, economical damage is significant in nurseries, which also contribute towards spread of the disease, but damage to forests is increasing. The study presents the results of mycological and histological investigations on three hundred 3‐year‐old nursery ash saplings. The infection rate by the causative pathogen was determined for bark, outer and inner xylem, the pith and also separately for the above‐ground portion and root system of the plants. The invasion and colonization strategy of the fungus in the woody stem was examined. In addition, the presence of soil‐borne Oomycetes as possible primary or accompanying causal organisms was investigated. The results verify the dominant role of Chalara fraxinea as a causal agent of ash dieback and rule out the role of Oomycetes in the disease process. We conclude that C. fraxinea is not primarily endophytic in nature and spreads very effectively in the central stem tissues, which enables colonization of the woody stem in all three dimensions. Infections arising in the upper part of plants can thus spread extensively to lower parts.     

Bemerkenswerte Vitalitätsschwächung und Holzzersetzung an Rot-Buchen (Fagus sylvatica) durch den weitgehend unbekannten Schlauchpilz Hypoxylon cohaerens

In the years 2005 and 2006 several declining and recently died beech trees were investigated in a large city park in Dresden. The ascomycete Hypoxylon cohaerens, who is exclusively characterized as a saprophytic fungus by literature, was identified as a conspicuous cause of the disease. The symptoms of the infection, the morphologically and physiologically characteristics of the fungus in situ and in vitro as well as the factors of predisposition are presented in the article. Since H. cohaerens attains pathological importance and can be mistaken for some other ascomycetes, the distinguishing marks to related species are described. The changed importance of the fungus is evaluated for practice.     

Proof of concept to unmask the breeding value of genetic resources of barley (Hordeum vulgare) with a hybrid strategy

Broadening the genetic base of elite breeding programmes is crucial for further breeding success. The absence of major adaption genes, however, often masks the grain yield breeding value of genetic resources. We assessed the ability of a hybrid strategy to provide unbiased performance estimates of 21 barley genetic resources. By crossing them to elite tester lines, 25 three-way hybrids were produced and evaluated together with a part of their parents and eight elite hybrids for important agronomic traits in replicated field trials in four environments. The phenotypic data analyses revealed that the hybrid strategy facilitated to identify promising resources by substantially improving lodging resistance. Combining genotypic data for 5,562 SNPs with the phenotypic data highlighted the potential to boost the diversity of the elite breeding pool via targeted introgression of genetic resources into the male and female heterotic pools. We propose an application of the hybrid strategy for genetic resources of entire genebank collections and to use genome-wide predictions to support a targeted choice of accessions with high value for barley breeding.     

The concentrations of K,Rb and Cs in spruce needles (Picea abies Karst.) and in the associated soils

The elemental concentrations of K, Rb and Cs were determined in needles from individual spruce trees as a function of the needle age class. The concentrations are highest in current year's needles and decrease smoothly in older needles, approaching a constant value. Rb and Cs show similar behaviour, whereas that of K differs in so far as its relative decrease with time is less pronounced. Intra- and intersite variation of the needle concentrations are largest for Cs and smallest for K. Individual trees show a highly significant correlation between the log (Cs) and log (Rb) values. Total soil concentrations were determined at 9 sites with different parent material. Intra- and intersite variations of K are comparable for soils and for needles, whereas those for Rb and Cs are much smaller for soils than for needles. All three elements are correlated in soil samples. There is no close connection between soil and needle concentrations at the various sites. However, the results suggest that needle concentrations of Rb and Cs, but not of K, are strongly dependent on the sorption properties of the associated soils.     

Robust reconstitution of active cell-cycle control complexes from co-expressed proteins in bacteria

ABSTRACT: BACKGROUND: Cell proliferation is an important determinant of plant growth and development. In addition,modulation of cell-division rate is an important mechanism of plant plasticity and is key inadapting of plants to environmental conditions. One of the greatest challenges inunderstanding the cell cycle of flowering plants is the large families of CDKs and cyclins thathave the potential to form many different complexes. However, it is largely unclear whichcomplexes are active. In addition, there are many CDK- and cyclin-related proteins whosebiological role is still unclear, i.e. whether they have indeed enzymatic activity. Thus, abiochemical characterization of these proteins is of key importance for the understanding oftheir function. RESULTS: Here we present a straightforward system to systematically express and purify active CDKcyclincomplexes from E. coli extracts. Our method relies on the concomitant production of aCDK activating kinase, which catalyzes the T-loop phosphorylation necessary for kinaseactivity. Taking the examples of the G1-phase cyclin CYCLIN D3;1 (CYCD3;1), the mitoticcyclin CYCLIN B1;2 (CYCB1;2) and the atypical meiotic cyclin SOLO DANCERS (SDS) inconjunction with A-, B1- and B2-type CDKs, we show that different CDKs can interact withvarious cyclins in vitro but only a few specific complexes have high levels of kinase activity. CONCLUSIONS: Our work shows that both the cyclin as well as the CDK partner contribute to substratespecificity in plants. These findings refine the interaction networks in cell-cycle control andpinpoint to particular complexes for modulating cell proliferation activity in breeding.