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1.
An estrogen-binding protein and endogenous ligand in Saccharomyces cerevisiae: possible hormone receptor system 总被引：10，自引：0，他引：10
A protein macromolecule in the cytosol of the unicellular eukaryotic yeast Saccharomyces cerevisiae selectively binds the vertebrate estrogen hormone 17 beta-estradiol with high affinity. Lipid extracts of the yeast cells or the conditioned growth medium yield a substance that can bind competitively to the tritiated estradiol-binding sites in the yeast and to mammalian estrogen receptors. These findings suggest that the binding protein may be a primitive hormone receptor and that the lipid-extractable substance represents the endogenous ligand. 相似文献
2.
Loose M Fischer-Friedrich E Ries J Kruse K Schwille P 《Science (New York, N.Y.)》2008,320(5877):789-792
In the bacterium Escherichia coli, the Min proteins oscillate between the cell poles to select the cell center as division site. This dynamic pattern has been proposed to arise by self-organization of these proteins, and several models have suggested a reaction-diffusion type mechanism. Here, we found that the Min proteins spontaneously formed planar surface waves on a flat membrane in vitro. The formation and maintenance of these patterns, which extended for hundreds of micrometers, required adenosine 5'-triphosphate (ATP), and they persisted for hours. We present a reaction-diffusion model of the MinD and MinE dynamics that accounts for our experimental observations and also captures the in vivo oscillations. 相似文献
3.
A digestion trial was performed with 14 lactating Friesian dairy cows to compare the estimated digestibility of crude nutrients after collecting the faeces for 5, 7 and 9 d. The experimental ration consisted of grass silage (7.3 kg DM) and concentrate (10.9 kg DM). Animals were adapted to the ration for 14 d. There was no effect of the duration of the collection period on the estimated mean digestibility of crude nutrients and on the respective standard deviation. In consequence, in digestibility trials with cows the collection period must not exceed 5 d. 相似文献
4.
Hughan SC Loose JM Caddy DJ Canny BJ Tilbrook AJ Young IR 《Australian veterinary journal》2001,79(3):207-211
OBJECTIVE: To determine whether low dose xylazine with ketamine reduces the concentrations of cortisol and prolactin in sheep postoperatively and to characterise the effects of the drugs on behaviour during recovery. DESIGN: Analysis of variance was used to compare the effects of anaesthesia, surgery and combined ketamine/xylazine treatment on the plasma cortisol and prolactin concentrations and on behavioural variables in pregnant ewes subjected to abdominal surgery. PROCEDURE: Twelve ewes were randomly assigned to receive either ketamine/xylazine or placebo in association with anaesthesia and surgery. Both groups of ewes underwent anaesthesia alone followed a week later by anaesthesia with laparotomy and hysterotomy. Plasma cortisol and prolactin concentrations were assayed during these procedures and for 5 days afterwards. Behavioural observations were made remotely during recovery from anaesthesia and anaesthesia plus surgery. RESULTS: The concentrations of cortisol in the plasma of pregnant ewes undergoing surgery were increased by preoperative handling and the onset of thiopentone/halothane anaesthesia, with a further increase during surgery (P = 0.033). Cortisol concentrations decreased over the first four postoperative hours (P = 0.029) and were normal by 24 h. The drug treatment did not affect the immediate responses of ewes to anaesthesia or surgery, although treated ewes had lower cortisol concentrations than saline-treated controls over the first five postoperative days (P = 0.018). Prolactin concentrations increased in response to anaesthesia (P = 0.047), but were not affected by surgery or the drug treatment. Drug-treated ewes had prolonged sleeping time after surgery (P = 0.002), but they took no longer to stand than saline-treated controls and required fewer attempts to stand successfully (P = 0.025). CONCLUSION: At the doses used, ketamine and xylazine did not mitigate the immediate endocrine consequences of surgery but the behavioural data provide a basis for further investigations that may lead to improvements in analgesic treatments. 相似文献
5.
R. De Loose 《Euphytica》1979,28(1):105-113
Summary A radiation-induced chimeric flower colour sport of vegetatively propagated Rhododendron simsii
Planch. was recurrently irradiated (up to three times in three consecutive years) with soft X-rays (50kV-30mA), as compared to a single treatment. Because of the low true flower colour mutation frequency the efficiency of the different radiation treatments was compared on the basis of the number of chimeric rearrangements in flower structure i.e. the flower colour change from red with broad white edge towards either homogeneous carmine-red or white.It is quite clear that recurrent irradiation with appropiate doses is most efficient. 相似文献
6.
Marc De Loose Xavier Danthinne Erik Van Bockstaele Marc Van Montagu Ann Depicker 《Euphytica》1955,85(1-3):209-216
Summary Three random synthetic leaders and three naturally-occurring leaders, the tobacco mosaic virus (TMV) coat protein, the satellite tobacco necrosis virus (STNV) and the plant chlorophyll a/b-binding protein (Cab22L), were shown to modulate the -glucuronidase reporter protein accumulation levels in transient expression experiments. The same chimeric constructs also confer differential distribution patterns of reporter protein accumulation in stably-transformed tobacco calli or regenerated transgenic plants. When the highest expression levels with a given leader are compared, the 31-nucleotide random leader stimulates translation 20- and 100-fold relative to the 9- and 4- nucleotide synthetic leaders respectively. However, this 31-nucleotide random leader is approx. 2 to 3-fold weaker than the 30-nucleotide STNV leader and even 5-fold weaker than both the 79-nucleotide TMV leader and the 66-nucleotide Cab22L leader. These results confirm the findings in transient expression experiments and stress the importance of the 5-untranslated region for the production of heterologous proteins in transgenic plants. 相似文献
7.
R. De Loose 《Scientia Horticulturae》1978,9(3):285-290
The influence of epidermal tissue pH on flower colour was studied in 104 cultivars of Azalea indica (Rhododendron simsii Planch.). Based on H.C.C. visual colour number, cultivars were classified in 4 colour groups: purple; carmine red; red; white.A method for pH determination using microvolumes (30 μl) on a microelectrode has been perfected. Within each colour group, flower colour was determined within a mean pH environment of 3.04 ± 0.06. Epidermal pH was approximately 0.3 units lower than the pH of the expressed sap of entire petals. Purple colours occurred with co-pigmented malvidin or delphinidin glycosides. Carmine red and red colours were produced by the same cyanidin glycosides that in the case of carmine red were co-pigmented with flavonol glycosides. The lower the content of anthocyanins (cyanidin glycosides) and the higher that of flavonols, the bluer the red (higher H.C.C. number; bathochromic shift of about 20 nm). A carmine red flower colour (± 58 B) may also occur when delphinidin glycosides occur in the absence of flavonol glycosides (pH < 4).Prospects for obtaining a blue flower colour are, because of low epidermal pH, very small. 相似文献
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9.
Platteau C De Loose M De Meulenaer B Taverniers I 《Journal of agricultural and food chemistry》2011,59(21):11395-11402
Hazelnuts (Corylus avellana) are used widely in the food industry, especially in confectionery, where they are used raw, roasted, or in a processed formulation (e.g., praline paste and hazelnut oil). Hazelnuts contain multiple allergenic proteins, which can induce an allergic reaction associated with symptoms ranging from mild irritation to life-threatening anaphylactic shock. To date, immunochemical (e.g., ELISA or dipstick) and PCR-based analyses are the only methods available that can be applied as routine tests. The aim of this study is to make a comparative evaluation of the effectiveness of ELISA and real-time PCR in detecting and correctly quantifying hazelnut in food model systems. To this end, the performances of two commercial ELISAs were compared to those of two commercial and one in-house-developed real-time PCR assays. The results showed that although ELISA seemed to be more sensitive compared to real-time PCR, both detection techniques suffered from matrix effects and lacked robustness with regard to food processing. As these impacts were highly variable among the different evaluated assays (both ELISA and real-time PCR), no firm conclusion can be made as to which technique is suited best to detect hazelnut in (processed) food products. In this regard, the current lack of appropriate DNA calibrators to quantify an allergenic ingredient by means of real-time PCR is highlighted. 相似文献
10.
Veerle Lamote Joost Baert Isabel Roldán-Ruiz Marc De Loose Erik Van Bockstaele 《Euphytica》2002,123(2):159-164
Several genotypes of Lolium perenne (2n = 2x = 14) were screenedfor the production of 2n eggs. In each cross a diploid genotype, used asfemale parent, was pollinated with a tetraploid genotype. All interploidycrosses were made in isolation cages. Flow cytometrical analysis of theprogeny of 154 diploid plants revealed 28 tetraploid descendants. Theseoffspring plants were harvested on 15 different diploid mother plants.Amplified Fragment Length Polymorphism (AFLP) markers were used tocheck the parenthood of these tetraploids. Two seedlings died, theremaining plants could, after AFLP fingerprinting, be identified as meiotictetraploids. The results obtained allowed to conclude that the tetraploidprogeny plants harvested on 15 diploid mother plants were the result ofthe fertilisation of an unreduced egg by a reduced pollen grain of thetetraploid plant. 相似文献