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1.
Cordenonsi M Montagner M Adorno M Zacchigna L Martello G Mamidi A Soligo S Dupont S Piccolo S 《Science (New York, N.Y.)》2007,315(5813):840-843
During development and tissue homeostasis, cells must integrate different signals. We investigated how cell behavior is controlled by the combined activity of transforming growth factor-beta (TGF-beta) and receptor tyrosine kinase (RTK) signaling, whose integration mechanism is unknown. We find that RTK/Ras/MAPK (mitogen-activated protein kinase) activity induces p53 N-terminal phosphorylation, enabling the interaction of p53 with the TGF-beta-activated Smads. This mechanism confines mesoderm specification in Xenopus embryos and promotes TGF-beta cytostasis in human cells. These data indicate a mechanism to allow extracellular cues to specify the TGF-beta gene-expression program. 相似文献
2.
Splice variants of the alpha subunit of the G protein Gs activate both adenylyl cyclase and calcium channels 总被引：10，自引：0，他引：10
R Mattera M P Graziano A Yatani Z Zhou R Graf J Codina L Birnbaumer A G Gilman A M Brown 《Science (New York, N.Y.)》1989,243(4892):804-807
Signal transducing guanine nucleotide binding (G) proteins are heterotrimers with different alpha subunits that confer specificity for interactions with receptors and effectors. Eight to ten such G proteins couple a large number of receptors for hormones and neurotransmitters to at least eight different effectors. Although one G protein can interact with several receptors, a given G protein was thought to interact with but one effector. The recent finding that voltage-gated calcium channels are stimulated by purified Gs, which stimulates adenylyl cyclase, challenged this concept. However, purified Gs may have four distinct alpha-subunit polypeptides, produced by alternative splicing of messenger RNA. By using recombinant DNA techniques, three of the splice variants were synthesized in Escherichia coli and each variant was shown to stimulate both adenylyl cyclase and calcium channels. Thus, a single G protein alpha subunit may regulate more than one effector function. 相似文献
3.
Genchi C Cody R Pengo G Büscher G Cavalleri D Bucci V Junquera P 《Veterinary parasitology》2004,122(4):287-292
The efficacy of a combination of milbemycin oxime and praziquantel in preventing the establishment of experimentally induced heartworm (Dirofilaria immitis) infection was investigated in a study involving 24 young domestic short-hair cats. The animals were inoculated with 50 infective larvae on day 0. Subsequently they were divided into two groups of 12 animals each. The animals in group 1 were treated once with medicated tablets containing 4 mg milbemycin (minimum dose 2 mg/kg body weight) and 10 mg praziquantel (MILBEMAX) on day 30 after infection. Cats in group 2 received placebo tablets on the same day. On day 183 post-infection a blood sample was taken from each animal before euthanasia and necropsy. The blood samples were tested for the presence of microfilariae and the necropsied animals were examined for the presence of adult worms. Microfilariae were not found in any of the investigated cats. No heartworms were found in the animals in group 1 (treated with medicated tablets). Out of the 12 placebo-treated cats 1 was heartworm-free, whereas all the others were found to be infected with 1-3 adult heartworms. 相似文献
4.
Undesirable characteristic of rapeseed oil is a relatively high level of linolenic acid (18:3), which is easily oxidized leading
to rancidity and a shortened shelf life of the oil. Previous attempts to reduce linolenic acid levels in rapeseed oil through
breeding have been impaired by complex genetics and strong environmental sensitivity of this trait. Therefore, our objective
was to develop molecular markers for low linolenic acid that could facilitate the breeding of low linolenic rapeseed. Bulked
segregant analysis was employed to identify two RAPD markers associated with 18:3 in a doubled haploid population segregating
for linolenic and erucic acid levels. Based on analysis of individual DH lines, the markers RM350 and RM574, representing
two independent loci, accounted for a total of 39% of the genetic variability in this population. This marker RM350 alone
accounted for 25% genetic variation for this trait with no evidence of recombination. Significant interlocus interaction found
between the markers RM350 and RM574 suggested that epistasis was involved in the genetic control of 18:3 level in this population.
Another marker designated as RM322, which was independent of the other two, was found significantly associated with the erucic
acid level and oil content. RAPD markers identified in this study should be a useful tool for the early detection of low linolenic,
or low or high erucic acid genotypes in rapeseed breeding programs based on doubled haploids.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Pearling by‐products and the pearled products of two commercial stocks of hulled barley, pearled according to an industrial process consisting of five consecutive pearling steps, were analyzed for β‐glucans, dietary fiber (total, soluble, and insoluble), protein, lipid, ash, and digestible carbohydrate. The data showed that the pearling flour fractions, abraded in the fourth and fifth hullers, contained interesting amounts of β‐glucans (3.9–5.1% db) from a nutritional point of view. These fractions were subsequently enriched in β‐glucans using a milling‐sieving process to double β‐glucan content (9.1–10.5% db). Functional pastas, enriched with β‐glucans and dietary fiber, were produced by substituting 50% of standard durum wheat semolina with β‐glucan‐enriched barley flour fractions. Although darker than durum wheat pasta, these pastas had good cooking qualities with regard to stickiness, bulkiness, firmness, and total organic matter released in rinsing water. The dietary fiber (13.1–16.1% wb) and β‐glucan (4.3–5.0% wb) contents in the barley pastas were much higher than in the control (4.0 and 0.3% wb, respectively). These values amply meet the FDA requirements of 5 g of dietary fiber and 0.75 g of β‐glucans per serving (56 g in the United States and 80 g in Italy). At present, the FDA has authorized the health claim “may reduce the risk of heart disease” for food containing β‐glucans from oat and psyllium only. 相似文献
6.
Vrhovsek U Guella G Gasperotti M Pojer E Zancato M Mattivi F 《Journal of agricultural and food chemistry》2012,60(10):2507-2516
Although the composition of strawberry fruit has been extensively studied, especially for the most abundant phenolic compounds, agrimoniin has never been univocally identified as one of the most abundant phenolic compounds in the fruit. In this study agrimoniin was isolated in the fruit of Fragaria vesca and its structure characterized. Furthermore, its presence was definitively established to be the main ellagitannin in both F. vesca and Fragaria ananassa D. fruit. The presence of sanguiin H-6 and lambertianin C as minor compounds was confirmed in both F. vesca and F. ananassa D. samples. For the first time here is reported the full NMR assignments for agrimoniin. These data should represent a point of reference for NMR analysis of this and other structurally related ellagitannins. Finally, the establishment of an HPLC protocol for separation provided information making it possible to avoid confusion with sanguiin H-6, the main ellagitannin in Rubus species, which is also present in strawberries but at a much lower concentration. 相似文献
7.
T. Mimmo D. Del Buono R. Terzano N. Tomasi G. Vigani C. Crecchio R. Pinton G. Zocchi S. Cesco 《European Journal of Soil Science》2014,65(5):629-642
Poor iron (Fe) availability in soil represents one of the most important limiting factors of agricultural production and is closely linked to physical, chemical and biological processes within the rhizosphere as a result of soil–microorganism–plant interactions. Iron shortage induces several mechanisms in soil organisms, resulting in an enhanced release of inorganic (such as protons) and organic (organic acids, carbohydrates, amino acids, phytosiderophores, siderophores, phenolics and enzymes) compounds to increase the solubility of poorly available Fe pools. However, rhizospheric organic compounds (ROCs) have short half‐lives because of the large microbial activity at the soil–root interface, which might limit their effects on Fe mobility and acquisition. In addition, ROCs also have a selective effect on the microbial community present in the rhizosphere. This review aims therefore to unravel these complex dynamics with the objective of providing an overview of the rhizosphere processes involved in Fe acquisition by soil organisms (plants and microorganisms). In particular, the review provides information on (i) Fe availability in soils, including mineral weathering and Fe mobilization from soil minerals, ligand and element competition and plant‐microbe competition; (ii) microbe–plant interactions, focusing on beneficial microbial communities and their association with plants, which in turn influences plant mineral nutrition; (iii) plant–soil interactions involving the metabolic changes triggered by Fe deficiency and the processes involved in exudate release from roots; and (iv) the influence of agrochemicals commonly used in agricultural production systems on rhizosphere processes related to Fe availability and acquisition by crops. 相似文献
8.
Matteo Alessandro Saladini Laura Asteggiano Marco Giuseppe Pansa Luca Giordani Luca Serre Graziano Vittone 《国际虫害防治杂志》2016,62(3):214-221
The European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), is a well-known species that is cosmopolitan and present throughout Europe. Due to its omnivorous feeding behaviour, this species can act as a generalist predator, preying on several top fruit pests, but also as a pest causing shallow gouges or holes in stone and soft fruits such as apricots, strawberries, raspberries or blackberries. In Piedmont (NW Italy), significant fruit damage has been observed lately in apricot orchards where earwigs fed on ripening fruits and made a considerable part of the produce unmarketable. In this study, we sampled earwig populations in three apricot orchards in Piedmont and tested the effectiveness of glue barriers applied to the tree trunks in reducing both earwig density in the canopy and fruit damage. The arboreal glues Rampastop® and Vebicolla® were tested both in the field and laboratory trials. Glue barriers demonstrated to be effective control measures, significantly reducing earwig abundance in the canopy and fruit damage. Rampastop® gave better results on old trees with a very rough and cracked bark, since in that case Vebicolla® could not perfectly bond with the trunk. 相似文献
9.
The kernel characteristics and composition, milling performance, protein quality, and alveograph parameters of five spelt cultivars grown in European countries were determined in relation of their utilization in pasta products. Long pasta was manufactured and chemically characterized, and its quality was assessed by sensory and chemical tests. Protein and fat contents were high in the grains (15.7 and 4.4% db, mean value, respectively). Total fiber varied from 10.5 to 14.9% db. The average β-glucan content was 1.2% db. The milling performance as determined by yield, damaged starch, ash, and particle-size distribution in the flour was uniform among the five cultivars. The results of the SDS sedimentation and gluten index tests indicated that spelt gluten strength was low, and this was confirmed by the alveograph test. Sensory and chemical evaluations of the pastas, however, indicated that spelt is suitable for obtaining good-quality pasta. The combination of the high protein content and the high-temperature drying cycle adopted in pasta production could be responsible for these good results. 相似文献
10.
Area 5 in the parietal lobe of the primate brain is thought to be involved in monitoring the posture and movement of the body. In this study, neurons in monkey area 5 were found to encode the position of the monkey's arm while it was covered from view. The same neurons also responded to the position of a visible, realistic false arm. The neurons were not sensitive to the sight of unrealistic substitutes for the arm and were able to distinguish a right from a left arm. These neurons appear to combine visual and somatosensory signals in order to monitor the configuration of the limbs. They could form the basis of the complex body schema that we constantly use to adjust posture and guide movement. 相似文献