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M. G. Wagener S. Leonhard‐Marek J.‐D. Häger C. Pfarrer 《Anatomia, histologia, embryologia》2018,47(3):268-270
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. 相似文献
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Pérez-Brígido Carlos D. Romero-Salas Dora Pardío-Sedas Violeta T. Cruz-Romero Anabel González-Hernández Milagros Delprá-Cachulo Joyce Mara Ascencio Mariano Florin-Christensen Mónica Schnittger Leonhard Rodríguez Anabel E. 《Veterinary research communications》2022,46(1):295-302
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... 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Leonhard Sommer Monika Spiller Gunther Stiewe Klaus Pillen Jochen C. Reif Albert W. Schulthess 《Plant Breeding》2020,139(3):536-549
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. 相似文献
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The concentrations of K,Rb and Cs in spruce needles (Picea abies Karst.) and in the associated soils
Armin Wyttenbach Sixto Bajo Jürg Bucher Verena Furrer Patrick Schleppi Leonhard Tobler 《植物养料与土壤学杂志》1995,158(5):499-504
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. 相似文献
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Agustina Perez-Llaneza Marina Caballero Eugenia Baravalle Maria Mesplet Juan Mosqueda Carlos E. Suarez Ignacio Echaide Frank Katzer Gabriela M. Pacheco Monica Florin-Christensen Leonhard Schnittger 《Veterinary parasitology》2010,167(2-4):196-204
Mini- and microsatellite sequences have proven to be excellent tools for the differentiation of strains and populations in several protozoan parasites due to their high variability. In the present work we have searched the genome of the tick-transmitted bovine hemoprotozoon Babesia bovis for tandem repeats (TRs) that could be useful for a multilocus typing system. Hundred and nineteen sequences were shortlisted and tested in five common B. bovis reference isolates originating from distinct geographic locations of North and South America: Texas, USA (T2Bo), Mexico (RAD and Mo7), and Santa Fe and Salta, Argentina (R1A and S2P, respectively). Satellite sequences were PCR-amplified using specific primers, separated by polyacrylamide gel electrophoresis, visualized by silver staining and sized. Fourteen TR sequences could be reliably amplified in all isolates and displayed length polymorphism. All primers used were specific for B. bovis and did not amplify genomic DNA from the bovine host or from Babesia bigemina, the principal co-infecting bovine parasite in the Americas, allowing their future use in field surveys. The 14 satellite markers identified are distributed throughout the four chromosomes of B. bovis as follows: chromosome 1 (n = 3), chromosome 2 (n = 2), chromosome 3 (n = 5), and chromosome 4 (n = 4). Within the five B. bovis isolates we identified nine satellite marker loci with two alleles, three with three alleles, one with four and another with five alleles. In comparison to Theileria parva, a bovine hemoprotozoan that pertains to the same piroplasmida order and owns a genome of similar size, the number of polymorphic TRs and the average number of alleles per TR locus seem to be significantly reduced in the B. bovis genome. Furthermore, the ratio of micro- to minisatellites in both B. bovis and T. parva is considerably lower than in other eukaryotes, as confirmed by bioinformatic analysis. The multilocus genotype of the five B. bovis isolates was assessed and the genetic distance between each other determined followed by cluster analysis based on neighbor joining. The resulting phenogram showed that B. bovis isolates segregated into three clusters according to their geographic origin. The presented marker system is suitable to explore various parameters of B. bovis populations such as genetic diversity, infection dynamics and their structure under different epidemiological situations, which are of crucial importance for improved control strategies. 相似文献