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101.
Essential oils were eamined in nine clones of Mentha arvensis, four clones of M. spicata, and 20 clones of M. gracilis. An F1 hybrid of M. arvensis M. spicata, selected on the basis of morphology and chromosome number, was matched with one clone of M. Gracilis. Genes for the inheritance of limonene, 1,8-cineole, linalool, isomenthone, carvone, and piperitenone oide were identified in one clone of M. arvensis and two clones of M. spicata. The range of essential oil compounds detected indicates that no one character can be used to identify M. gracilis, but the critical compounds of the oil of M. gracilis can be derived from crosses of M. arvensis M. spicata. 相似文献
102.
J R Merwin A Tucker L Madisen A Purchio J Madri 《Biochemical and biophysical research communications》1991,175(2):589-595
Functional biological assays were performed using a hybrid molecule of Transforming Growth Factor-Beta (TGF-5 beta) where nine amino acids near the cleavage site of TGF-beta 1 were substituted with nine amino acids located in the identical position of TGF-beta 2. Bovine aortic endothelial and smooth muscle cells as well as rat epididymal fat pad microvascular endothelia were studied in three distinct bioassays examining proliferation, migration and angiogenesis. The data suggested TGF-5 beta elicited results that do not differ significantly from the TGF-beta 1 isoform, while TGF-beta 2 expressed unique characteristics. We have also shown that these amino acid substitutions to TGF-beta 1 do not, in fact, alter the biological functions of the growth factor. 相似文献
103.
Graeme D. Coles D. J. Abernethy Mary C. Christey A. J. Conner B. K. Sinclair 《Plant Molecular Biology Reporter》1991,9(1):13-20
Hairy roots, incited byAgrobacterium rhizogenes, form a useful system for analysing the expression and phenotypic effects of foreign genes in plant root tissue. Image analysis
offers a non-invasive method of describing their growth in culture. Images of pea (coarse) andBrassica (fine) hairy roots were captured, processed and analysed without difficulty using a commercially available image analysis
system. The value of this method in monitoring intermediate changes in growth pattern was illustrated by following the changes
in five putatively chlorsulfuron-resistantBrassicc hairy-root lines cultured with and without a selective level of chlorsulfuron. Areas of hairy-root research where this technique
will be particularly useful are discussed. 相似文献
104.
Employing nine clones ofMentha arvensis and four clones ofM. spicata, 932 F, hybrids were synthesized and compared to 20 clones ofM. x gracilis. Two clones ofM. x gracilis with 60 somatic chromosomes were matched to a selected F1 hybrid. The other 18 clones ofM. x gracilis had somatic chromosome numbers of 60, 72, 84, and 96, and while these chromosome numbers appeared in the F1 progeny, morphological matches correlated with their correct chromosome numbers were not synthesized. The range of pollen and seed fertility, as well as the inheritance of male-sterility, leaf pubescence, and crispness, indicates that no one character can be used to identifyM. x gracilis, but all characters can be explained fromM. arvensis x M. spicata. 相似文献
105.
Anthony V. Capuco Pamela A. Feldhoff R.Michael Akers James L. Wittliff H.Allen Tucker 《Steroids》1982,40(5):503-517
Binding of [3H]R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3, 20-dione) to bovine mammary cytosol indicated the presence of progestin binding sites of high-affinity and low-capacity in tissue from prepartum, nonlactating and from postpartum, lactating cows. To prevent binding of [3H]R5020 to glucocorticoid binding sites, a 200-fold molar excess of nonradioactive cortisol was included during all incubations, thus specific binding was limited to progestin binding sites. Nonradioactive R5020 and progesterone effectively inhibited [3H]R5020 binding to progestin binding sites, while estradiol-17β, dihydrotestosterone (17β-hydroxy-5α-androstan-3-one), dexamethasone (9-fluoro-11β, 17, 21-trihydroxy-16α-methyl-1,4-pregnadiene-3,20-dione) or additional cortisol were ineffective. Dissociation constants for specifically bound [3H]R5020 in cytosol from mammary tissue of nonlactating and lactating cows were nearly identical, averaging 1.9 ( ± 0.3) and 0.8( ± 0.2) × 10?9M, respectively. However, binding capacities (fmol/mg cytosolic protein) were greater in cytosol from prepartum, nonlactating (179 ± 53) than postpartum, lactating (41 ± 15) cows. Specific binding components in cytosol from lactating cows sedimented in the 6-7S region on linear sucrose density gradients. When subjected to isoelectric focusing, specific binders with isoelectric points (pI) of approximately 6.1, 7.9 and 8.3 were resolved. The decrease in number of binding sites during lactation was due to the virtual absence of the anionic binding species, suggesting that their presence is necessary for progesterone to inhibit milk secretion. 相似文献
106.
107.
Craig S. Tucker 《Hydrobiologia》1981,85(1):73-76
Eichhornia crassipes (Mart.) Solms, Pistia stratiotes (L.), and Lemna minor (L.) were cultured at four different densities each and analyzed for cell-wall fraction, crude protein, total available carbohydrate and ash. Cell-wall fraction increased and crude protein content decreased as density increased in Eichhornia and Pistia cultures. The cell-wall and crude protein content of Lemna did not change with increasing culture density. Differences in the trends of cell-wall and crude protein content of the three plants at increasing culture densities appear to be related to differences in growth form. There was no difference in the total available carbohydrate or ash content of the three species at different culture densities. 相似文献
108.
Transformation of Rhodopseudomonas sphaeroides with deoxyribonucleic acid isolated from bacteriophage R phi 6P. 总被引:2,自引:2,他引:0
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The transformation of the photosynthetic bacterium Rhodopseudomonas sphaeroides with the circular genome of the penicillinase-encoding, temperate bacteriophage R phi 6P was demonstrated. The transformation was dependent on the infection of the recipient by another, apparently closely related, temperature bacteriophage, R phi 9. Optimum transformation occurred in the recipient cells already lysogenic for R phi 9 when superinfected with that bacteriophage at multiplicities of infection between 1 and 10 R phi 9 particles per recipient cell. 相似文献
109.
Pritam Singh Graeme B. Russell Yuji Hayashi Rex T. Gallagher Susan Fredericksen 《Entomologia Experimentalis et Applicata》1979,25(2):121-127
The effects on housefly (Musca domestica) of six norditerpene lactones (nagilactones B, D, E, podolide, hallactone B and 14-epi-ponalactone A) in a defined diet were tested. Nagilactone D was the most active, with an LD50 of 0.7 ppm. Nagilactones C and D were also toxic to light-brown apple moth (Epiphyas postvittana) and codling moth (Laspeyresia pomonella).The relationship between lactone structure and toxicity to housefly is discussed.
Zusammenfassung Viele aus Podocarpus-Arten isolierte Norditerpenlactone sind für Stubenfliegen toxisch. Es wird über die Resultate der Fütterung von sechs Lactonen an die Stubenfliege in einem definierten Nährboden berichtet und die LD50 von zwölf Verbindungen werden verglichen. Der aktivste Stoff ist Nagilacton mit einer LD50 von 0,7 ppm. Nagilacton C und D sind auch toxisch für Epiphyas postvittana und für den Apfelwickler. Die wirksamsten Verbindungen haben eine kurze nichtpolare Seitenkette und eine elektronenreiche, funktionelle Gruppe bei C-8, ferner sind sie Epoxyalkohole in Ring-A. Diese in der Natur vorkommenden Lactone spielen wahrscheinlich eine Schutzrolle in der Pflanze.相似文献
110.