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991.
Regina Hühn Heike Stoermer Beate Klingele Elke Bausch Alberto Fois Mariangela Farnetani Maja Di Rocco Joelle Boué Jean M. Kirk Rosalind Coleman G. Scherer 《Human genetics》1998,102(3):305-313
Tyrosinemia typeII (Richner-Hanhart syndrome, RHS) is a disorder of autosomal recessive inheritance characterized by keratitis,
palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in
hepatic tyrosine aminotransferase (TAT). We have previously described one deletion and six different point mutations in four
RHS patients. We have now analyzed the TAT genes in a further seven unrelated RHS families from Italy, France, the United Kingdom, and the United States. We have established
PCR conditions for the amplification of all twelve TAT exons and have screened the products for mutations by direct sequence analysis or by first performing single-strand conformation
polymorphism analysis. We have thus identified the presumably pathological mutations in eight RHS alleles, including two nonsense
mutations (R57X, E411X) and four amino acid substitutions (R119W, L201R, R433Q, R433W). Only the R57X mutation, which was
found in one Scottish and two Italian families, has been previously reported in another Italian family. Haplotype analysis
indicates that this mutation, which involves a CpG dinucleotide hot spot, has a common origin in the three Italian families
but arose independently in the Scottish family. Two polymorphisms have also been detected, viz., a protein polymorphism, P15S,
and a silent substitution S103S (TCG→TCA). Expression of R433Q and R433W demonstrate reduced activity of the mutant proteins.
In all, twelve different TAT gene mutations have now been identified in tyrosinemia typeII.
Received: 8 October 1997 / Accepted: 29 October 1997 相似文献
992.
Olfactory sensitivity in tsetse flies: a daily rhythm 总被引:3,自引:0,他引:3
The diurnal tsetse Glossina morsitans morsitans bites especially in early
morning and late afternoon; around midday feeding is at a low. In
laboratory apparatus that measures the amount of locomotion under constant
conditions over the photophase, the flies display a similar patterning of
activity levels. The profile of daily rhythms for G. morsitans reported in
the literature includes a number of motor and sensory motor systems that
fluctuate cophasically. Lacking is a study on the patterning of the senses'
response levels. In this paper we present the first instance of a daily
modulation in the sense of smell. We stimulated the antennae with
concentration series of host-derived odours and measured the spiking rate
of cells at different times during the photophase. The
concentration-response curves suggest that the sensitivity of antennal
olfactory cells flows in parallel with the other daily rhythms. This was
also reflected in electroantennograms (EAGs). The electroantennography was
extended to G. fuscipes fuscipes, whose level of spontaneous locomotor
activity--instead of following a U- shaped pattern--rises gradually over
the photophase. Again, the EAGs appeared to parallel the species' locomotor
activity. What we believe happens is that the organism tones down the
sensitivity of its odour receptors during periods of anticipated inactivity
for reasons of economy.
相似文献
993.
Extension of the 2-Deoxyglucose Method to the Fetus in Utero: Theory and Normal Values for the Cerebral Glucose Consumption in Fetal Guinea Pigs 总被引:1,自引:0,他引:1
Richard Berger Albert Gjedde Johannes Heck Elke Müller †Josef Krieglstein Arne Jensen 《Journal of neurochemistry》1994,63(1):271-279
Abstract: Fetal cerebral metabolism changes during development. The normal fetal metabolic rate must be known to evaluate pathophysiological changes. Therefore, we determined the regional cerebral glucose consumption in the fetal guinea pig. This required the application of the 2-deoxyglucose method to this species. We measured both the transfer coefficients of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the lumped constant in chronically prepared undisturbed guinea pig dams using a three-compartment model. Furthermore, the ratio between the initial clearances of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the ratio between the phosphorylation coefficients of these substrates in the fetal brain were determined. The total cerebral glucose consumption measured by the deoxyglucose method (10 ± 1.2 µmol/100 g/min) was similar to that calculated from the glucose concentration and the phosphorylation coefficient of glucose in the cerebrum (10 ± 0.4 µmol/100 g/min). We conclude that the 2-deoxyglucose method is applicable to the guinea pig, and we further conclude that in the fetal guinea pig cerebral glucose consumption is 10 times lower than that in the adult. 相似文献
994.
Abscisic acid (ABA) induces formation of a set of proteins in the xerophilic liverwortExormotheca holstii. Some of them have immunological properties similar to the dehydrins of desiccated corn embryos and the desiccation-related proteins ofCraterostigma plantagineum. The fluctuations of endogenous ABA during cycles of desiccation and rehydration seem to be sufficiently high to indicate a role for ABA as a stress hormone and there by as an endogenous inductor of stress-related protein synthesis. Desiccation tolerance disappears when thalli are cultivated for a longer period under well-watered conditions; such thalli are not able to increase stress-dependent ABA biosynthesis sufficiently, or to form the desiccation-related proteins unless they are treated with external ABA. The rehydrated thalli cannot recover from a rapid water loss, while ABA-treated, non-hardened thalli regain their photosynthetic activity within two hours.Abbreviations ABA
abscisic acid
- Fo
initial fluorescence yield
- Fm
maximum fluorescence yield
- QA
primary quinone receptor of PSII
We are grateful to Deutsche Forschungsgemeinschaft for financial support (SFB 251, TP3, Graduiertenkolleg Ka 456/5-1), to Prof. E.W. Weiler (Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany), Dr. D. Bartels (Max-Planck-Institut für Züchtungsforschung, Köln, Germany) and Dr. T.J. Close (Department of Botany and Plant Science, University of California, Riverside, Calif., USA) for generous gifts of immunochemicals for ABA assay and antibodies 6–19, 37-31 and Rb-2b, to Miss. B. Dierich for skilful technical assistance and to Mrs. E.M. Arnold, Omaruru, Namibia for the generous supply ofExormotheca thalli. 相似文献
995.
Reetta Haapala Susan Linko Elke Parkkinen Pirkko Suominen 《Biotechnology Techniques》1994,8(6):401-406
Summary Endo-1,4--glucanase and xylanase were produced by Trichoderma reesei immobilized on polyurethane foam using lactose as the main carbon source. The most porous carrier was found to be the best of those tested. The nitrogen source and KH2PO4 concentration of the production medium had a marked effect on culture pH during the course of fermentation and, consequently, on xylanase activity. An increase in lactose concentration from 7 to 27 g/l resulted in an increase in endoglucanase activity (max. 730 U/ml), xylanase activity (max. 3350 U/ml) and filter paper activity (max. 3.0 FPU/ml). 相似文献
996.
Houe H. Baker J.C. Maes R.K. Lloyd J.W. Enevoldsen C. 《Acta veterinaria Scandinavica》1995,36(4):521-531
Based on 2 previous surveys on the occurrence of infection with bovine virus diarrhoea virus (BVDV) in Danish and Michigan dairy herds, the prevalence and incidence of the infection were compared. The presence of certain possible risk factors for the occurrence of infection in the 2 areas were summarized and it was investigated if any of these risk factors had significant effect on the presence of animals persistently infected (PI) with BVDV in the dairy herds. Information on the cattle population density in the 2 areas was obtained from statistical yearbooks. Further information for the individual farms on age distribution, housing of animals, herd size, pasturing and purchasing policy was gathered. The prevalence of PI animals was more than 10 times higher in Denmark as compared to Michigan. In herds without PI animals, the annual incidence of seroconversion as calculated from the age specific prevalence of antibody carriers varied in most age groups between 20–25% in Denmark and between 5–10% in Michigan. All investigated risk factors except for herd size were in favour of a lower prevalence of infection in Michigan. The use of having animals on pasture and at the same time having purchased more than 40 animals within recent 31/2–4 years were significantly associated with presence of PI animals in the dairy herds (p = 0.01) when tested by the Mantel-Haenszel χ2. Using mul-tivariable logistic regression, the occurrence of PI animals was found to be significantly related to the study area (Michigan and Denmark) as well as to herd size and purchase intensity. 相似文献
997.
Gene activation by UV light, fungal elicitor or fungal infection in Petroselinum crispum is correlated with repression of cell cycle-related genes 总被引:11,自引:4,他引:7
998.
Arja E. I. Vainio Raija Lantto Elke E. M. Parkkinen Helena T. Torkkeli 《Applied microbiology and biotechnology》1994,41(1):53-57
A stable strain of Saccharomyces cerevisiae secreting glucoamylase (EC 3.2.1.3) with high debranching activity was constructed using recombinant DNA technology. An expression cassette without bacterial sequences, containing Hormoconis resinae glucoamylase P cDNA and the dominant selection marker MEL1 was integrated into the yeast chromosome using ARS1 homology. The glucoamylase expression level of the integrant yeast strain was increased by chemical mutagenesis. The yeast strains secreting glucoamylase were able to grow on soluble starch (5%, w/v) and ferment it to ethanol.Correspondence to: A. Vainio 相似文献
999.
Summary Two representative cultivars ofCicer arietinum, the desi-type cv.Annigeri and the kabuli-type cv.ICCV6, were regenerated in vitro and clonally propagated from cotyledonary
nodes and meristem tips. The explants were dissected from 1-wk-old seedlings aseptically germinated on WH medium. In both
cultivars, all nodes cultured on B5 medium supplemented with 4.4μM 6-benzylaminopurine developed up to seven shoots per node within 3 wk. Meristem tips were much better suited for multiple
shoot formation. Cultured on DKW-C-a medium supplemented with 4.4μM 6-benzylaminopurine and 0.05μM indole-3-butyric acid, 96% of the meristem tips produced up to 10 shoots per explant. A new method in improving clonal propagation
was subdividing the meristem tips. Doing so, multiple shoot formation was considerably enhanced: up to 90 shoots per original
explant could be obtained with cv.Annigeri, and up to 50 with cv.ICCV6. Indole-3-butyric acid proved to be the best rooting
factor. From several media tested, the best root induction and development was achieved on WH medium supplemented with 2.5μ M indole-3-butyric acid: 72% rooting with cv.Annigeri and 68% rooting with cv.ICCV6. With both cultivars there were no differences
in rooting capacity between shoots of nodal origin and those derived from meristem tips. The plantlets obtained were transferred
into soil and kept under greenhouse conditions. The survival frequency was 28% with cv.Annigeri and 23% with cv.ICCV6. R0 plants remained smaller than seed-grown controls and produced only a few fertile seeds. There was no difference between R1 plants and controls in growth, development, and seed set. 相似文献