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91.
Dagmar Weier Wilfried Lühs Josef Dettendorfer Margrit Frentzen 《Molecular breeding : new strategies in plant improvement》1998,4(1):39-46
The plsC gene of Escherichia coli encoding sn-1-acylglycerol-3-phosphate acyltransferase was modified by inserting an endoplasmic reticulum retrieval signal to its 3 end and introduced into rapeseed (Brassica napus L.) plants under the control of a napin promotor. In developing seeds from transgenic plants an sn-1-acylglycerol-3-phosphate acyltransferase activity was detectable which showed substrate specificities typical of the E. coli enzyme. Moreover, seed oil from the transformants unlike that from untransformed plants contained substantial amounts of triacylglycerol species esterified with very-long-chain fatty acids at each glycerol position. Analysis of fatty acids at the sn-2 position of triacylglycerol showed hardly any very-long-chain fatty acids in untransformed plants, but in certain transformants these fatty acids were present, namely about 4% erucic acid and 9% eicosenoic acid. These data demonstrate that the bacterial acyltransferase can function in developing rapeseed and alters the stereochemical composition of transgenic rape seed oil by directing very-long-chain fatty acids, especially cis-11 eicosenoic acid, to its sn-2 position. 相似文献
92.
Andrew Filer Philipp Antczak Greg N. Parsonage Holly M. Legault Margot O’Toole Mark J. Pearson Andrew M. Thomas Dagmar Scheel-Toellner Karim Raza Christopher D. Buckley Francesco Falciani 《PloS one》2015,10(3)
Synovial fibroblasts in persistent inflammatory arthritis have been suggested to have parallels with cancer growth and wound healing, both of which involve a stereotypical serum response programme. We tested the hypothesis that a serum response programme can be used to classify diseased tissues, and investigated the serum response programme in fibroblasts from multiple anatomical sites and two diseases. To test our hypothesis we utilized a bioinformatics approach to explore a publicly available microarray dataset including rheumatoid arthritis (RA), osteoarthritis (OA) and normal synovial tissue, then extended those findings in a new microarray dataset representing matched synovial, bone marrow and skin fibroblasts cultured from RA and OA patients undergoing arthroplasty. The classical fibroblast serum response programme discretely classified RA, OA and normal synovial tissues. Analysis of low and high serum treated fibroblast microarray data revealed a hierarchy of control, with anatomical site the most powerful classifier followed by response to serum and then disease. In contrast to skin and bone marrow fibroblasts, exposure of synovial fibroblasts to serum led to convergence of RA and OA expression profiles. Pathway analysis revealed three inter-linked gene networks characterising OA synovial fibroblasts: Cell remodelling through insulin-like growth factors, differentiation and angiogenesis through _3 integrin, and regulation of apoptosis through CD44. We have demonstrated that Fibroblast serum response signatures define disease at the tissue level, and that an OA specific, serum dependent repression of genes involved in cell adhesion, extracellular matrix remodelling and apoptosis is a critical discriminator between cultured OA and RA synovial fibroblasts. 相似文献
93.
Rocio Acuna-Hidalgo Denny Schanze Ariana Kariminejad Ann Nordgren Mohamad Hasan Kariminejad Peter Conner Giedre Grigelioniene Daniel Nilsson Magnus Nordenskjöld Anna Wedell Christoph Freyer Anna Wredenberg Dagmar Wieczorek Gabriele Gillessen-Kaesbach Hülya Kayserili Nursel Elcioglu Siavash Ghaderi-Sohi Payman Goodarzi Hamidreza Setayesh Maartje van de Vorst Marloes Steehouwer Rolph Pfundt Birgit Krabichler Cynthia Curry Malcolm G. MacKenzie Kym M. Boycott Christian Gilissen Andreas R. Janecke Alexander Hoischen Martin Zenker 《American journal of human genetics》2014
94.
95.
Dagmar Clough Michael Heistermann Peter M. Kappeler 《American journal of physical anthropology》2010,142(3):441-452
Parasites and infectious diseases represent ecological forces shaping animal social evolution. Although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. We conducted a longitudinal parasitological study on four groups of wild red‐fronted lemurs (Eulemur fulvus rufus) at Kirindy Forest, Madagascar, during two field seasons in consecutive years to investigate i) the degree of gastrointestinal parasite infection on population and individual levels and ii) factors potentially determining individual infection risk. Using a comprehensive dataset with multiple individually assignable parasite samples as well as information on age, sex, group size, social rank, and endocrine status (fecal androgen and glucocorticoid), we examined parasite infection patterns and host traits that may affect individual infection risk. In addition, we examined whether parasite infection affects mating and reproductive success. Our results indicated high variability in parasite infection on individual and population levels. Time of year and group size was important determinants of variability in parasite infection. Variation in hormone levels was also associated with parasite species richness and parasite infection intensity. Differences in parasite infection between years indicate a potential immune‐enhancing function of steroid hormones on nematode infections, which has not been reported before from other vertebrates studied under natural conditions. Male mating and reproductive success were not correlated to any measure of parasite infection, which suggests a nonfunctional role of the parasites we examined in primate sexual selection. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
96.
Dagmar Zunner Hans-Christian Kornau 《Biochemical and biophysical research communications》2010,393(2):185-189
GABAB receptors mediate slow inhibitory effects of the neurotransmitter γ-aminobutyric acid (GABA) on synaptic transmission in the central nervous system. They function as heterodimeric G-protein-coupled receptors composed of the seven-transmembrane domain proteins GABAB1 and GABAB2, which are linked through a coiled-coil interaction. The ligand-binding subunit GABAB1 is at first retained in the endoplasmic reticulum and is transported to the cell surface only upon assembly with GABAB2. Here, we report that GABAB1, via the coiled-coil domain, can also bind to soluble proteins of unknown function, that are affected in 22q11 deletion/DiGeorge syndrome and are therefore referred to as DiGeorge critical region 6 (DGCR6). In transfected neurons the GABAB1-DGCR6 association resulted in a redistribution of both proteins into intracellular clusters. Furthermore, the C-terminus of GABAB2 interfered with the novel interaction, consistent with heterodimer formation overriding transient DGCR6-binding to GABAB1. Thus, sequential coiled-coil interactions may direct GABAB1 into functional receptors. 相似文献
97.
Plants cope with cadmium (Cd) stress by complexation with phytochelatins (Pc), metallothioneins and glutathione and sequestration within vacuoles. Especially glutathione was found to play a major role in Cd detoxification as Cd shows a high binding affinity towards thiols and as glutathione is a precursor for Pc synthesis. In the present study, we have used an immunohistochemical approach combined with computer-supported transmission electron microscopy in order to measure changes in the subcellular distribution of glutathione during Cd-stress in mesophyll cells and cells of different glandular trichomes (long and short stalked) of Cucurbita pepo L. subsp. pepo var. styriaca Greb. Even though no ultrastructural alterations were observed in leaf and glandular trichome cells after the treatment of plants with 50 µM cadmium chloride (CdCl2) for 48 h, all cells showed a large decrease in glutathione contents. The strongest decrease was found in nuclei and the cytosol (up to 76%) in glandular trichomes which are considered as a major side of Cd accumulation in leaves. The ratio of glutathione between the cytosol and nuclei and the other cell compartments was strongly decreased only in glandular trichomes (more than 50%) indicating that glutathione in these two cell compartments is especially important for the detoxification of Cd in glandular trichomes. Additionally, these data indicate that large amounts of Cd are withdrawn from nuclei during Cd exposure. The present study gives a detailed insight into the compartment-specific importance of glutathione during Cd exposure in mesophyll cells and glandular trichomes of C. pepo L. plants. 相似文献
98.
Terminal deoxynucleotidyl transferase (TdT) contributes to the junctional diversity of immunoglobulin and T-cell receptors
by incorporating nucleotides in a template-independent manner. A closely related enzyme, polymerase μ (polμ), a template-directed
polymerase, plays a role in general end-joining double-strand break repair. We cloned zebrafish TdT and polμ and found them
to be 43% identical in amino acid sequence. Comparisons with sequences of other species revealed conserved residues typical
for TdT in the zebrafish sequence that support the template independence of this enzyme. Some but not all of these features
were identified in zebrafish polμ. In adult fish, TdT expression was most prominent in thymus, pro- and mesonephros, the primary
lymphoid organs in teleost fish and in spleen, intestine, and the tissue around the intestine. Polμ expression was detected
not only in pro- and mesonephros, the major sites for B-lymphocyte development, but also in ovary and testis and in all tissue
preparations to a low extent. TdT expression starts at 4 dpf and increases thereafter. Polμ is expressed at all times to a
similar extent. In situ studies showed a strong expression of TdT and polμ in the thymic cortex of 8-week-old fish. The characterization
of zebrafish TdT and polμ provide new insights in fish lymphopoiesis and addresses the importance and evolution of TdT and
polμ themselves. 相似文献
99.
Baculovirus DNA binding protein (DBP) binds preferentially single-stranded DNA in vitro and colocalizes with viral DNA replication sites. Here, its putative role as viral replication factor has been addressed by RNA interference. Silencing of DBP in Autographa californica multiple nucleopolyhedrovirus-infected cells increased expression of LEF-3, LEF-4, and P35. In contrast, expression of the structural genes coding for P39 and polyhedrin was suppressed while expression of genes coding for P10 and GP64 was unaffected. In the absence of DBP, viral DNA replication sites were formed, indicating replication of viral DNA. Electron microscopy studies, however, revealed a loss of formation of polyhedra and virus envelopment, suggesting that the primary role of DBP is viral formation rather than viral DNA replication. 相似文献
100.
In honeybees (Apis mellifera), the biogenic amine octopamine has been shown to play a role in associative and non-associative learning and in the division
of labour in the hive. Immunohistochemical studies indicate that the ventral unpaired median (VUM) neurones in the suboesophageal
ganglion (SOG) are putatively octopaminergic and therefore might be involved in the octopaminergic modulation of behaviour.
In contrast to our knowledge about the behavioural effects of octopamine, only one neurone (VUMmx1) has been related to a
behavioural effect (the reward function during olfactory learning). In this study, we have investigated suboesophageal VUM
neurones with fluorescent dye-tracing techniques and intracellular recordings combined with intracellular staining. Ten different
VUM neurones have been found including six VUM neurones innervating neuropile regions of the brain and the SOG exclusively
(central VUM neurones) and four VUM neurones with axons in peripheral nerves (peripheral VUM neurones). The central VUM neurones
innervate the antennal lobes, the protocerebral lobes (including the lateral horn) and the mushroom body calyces. Of these,
a novel mandibular VUM neurone, VUMmd1, exhibits the same branching pattern in the brain as VUMmx1 and responds to sucrose
and odours in a similar way. The peripheral VUM neurones innervate the antennal and the mandibular nerves. In addition, we
describe one labial unpaired median neurone with a dorsal cell body, DUMlb1. The possible homology between the honeybee VUM
neurones and the unpaired median neurones in other insects is discussed.
This work was supported by the DFG ME 365/24-2. 相似文献