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41.
Congenic anti-Lyt-3.1 sera have recently been produced by immunizing B6-Lyt-2a mice with thymocytes from either B6-Lyt-2a, Lyt-3a or B6-Lyt-2a, Lyt-3a, H-2k mice (Boos et al. 1978). Surprisingly, mice of the congenic strain B6 failed to produce either anti-Lyt-2.1 or anti-Lyt-3.1 cytotoxic antibodies after identical immunizations. To determine the genetic basis for the difference in response to Lyt-3.1, (B6 × B6-Lyt-2a)Fa mice and progeny of the backcross, (B6 × B6-Lyt-2a)F1 × B6-Lyt-2a, were immunized with B6-Lyt-2a, Lyt-3a, H-2k thymocytes. In addition, thymic biopsies of backcross progeny were performed and thymocytes tested for the Lyt-2.2 antigenic specificity. Results indicate that gene(s) governing the immune response to Lyt-3.1 is (are) linked to theLyt-2 locus, and that the responder allele (linked toLyt-2 a ) shows very poor penetrance in Lyt-2a/Lyt-2b mice. 相似文献
42.
In the sequence of superorders Rutiflorae-Santaliflorae-Araliiflorae-Asteriflorae an increase in the mean oxidation state for each series of Cn-polyacetylenes and an extension in the range of the carbon atoms of these polyacetylenes in the direction of smaller numbers are observed. These trends of polyacetylene evolution also seem to be operative at lower hierarchic levels in the family Asteraceae. 相似文献
43.
Stanislaw Kowalczyk Anna Jakubowska Elbieta Zieliska Robert S. Bandurski 《Physiologia plantarum》2003,119(2):165-174
1- O -(indole-3-acetyl)- β - d -glucose: myo -inositol indoleacetyl transferase (IA- myo -inositol synthase) is an important enzyme in IAA metabolism. This enzyme catalyses the transfer of the indole acetyl (IA) moiety from 1- O -(indole-3-acetyl)- β - d -glucose to myo -inositol to form IA- myo- inositol and glucose. IA- myo -inositol synthase was purified to an electrophoretically homogenous state from maize liquid endosperm by fractionation with ammonium sulphate, anion-exchange, adsorption on hydroxylapatite, affinity chromatography on ConA-Sepharose, preparative PAGE and isoelectric focusing. We thus obtained two enzyme preparations which differ in their R f on 8% polyacrylamide gel. The preparation of R f 0.36 contained a single 56.4 kDa polypeptide, whereas the preparation of R f 0.39 consisted of two polypeptides of 56.4 and 53.5 kDa. Both purified preparations of IAInos synthase also exhibited the activity of an IAInos hydrolase, showing that the dual activity was associated with a single protein. Results of gel filtration and analytical SDS-PAGE suggest that the native enzyme exists as both a monomeric (65 kDa) and homo- or heterodimeric form (110–130 kDa). Analysis of peptide maps and amino acid sequences of two 21 amino-acid peptides showed that polypeptides of 56.4 and 53.5 kDa have the same primary structure and that the 3 kDa difference in molecular mass is probably caused by different glycosylation levels. Comparison of this partial and internal amino acid sequence with sequences of other plant acyltransferases indicated similarity to several proteins which belonged to the serine carboxypeptidase-like (SCPL) acyltransferase family. 相似文献
44.
45.
Anna Spalletti 《Photochemical & photobiological sciences》2004,3(7):695-699
Irradiation of the ZZ stereoisomer of 1,4-di-(2'-quinolylethenyl)-benzene was found to cause direct adiabatic (one photon-two bond) isomerization to a product having the same lifetime as the EE isomer but a rather different spectrum with respect to that obtained by direct excitation of the EE one. To clarify this unexpected behaviour, the conformational equilibria of the EE stereoisomer have been studied in non-polar solvent by fluorimetry. The most abundant conformers, formed by the hindered rotation of the condensed-ring groups around the quasi-single bond with the ethenic carbons, have been characterized by the selective effect of the excitation energy on the fluorescence spectrum. The combined application of the principal component analysis allowed the separation of the spectral properties of three conformers to be achieved. Information on their structures was obtained by theoretical calculations. The results of the present conformational study clearly indicated that the fluorescence spectrum of the photoproduct of ZZ belongs to a specific component of the conformer mixture of the EE isomer. 相似文献
46.
Anna Nowakowska-Waszczuk Andrzej Sokoŀowski 《Applied microbiology and biotechnology》1987,26(4):363-364
Summary In an air-lift fermenter, the following production was obtained from 125 g sucrose in mineral medium at pH 2.5 : 15.76 g mycelium dry wt, 107.2 g citric acid anhydrous and 0.594 mol CO2 within 138 h (run I) and 13.72 g mycelium dry wt, 114.28 g citric acid and 0.516 mol CO2 within 144 h (run II). Initially, the carbon content of consumed sugar and products did not balance. At the end of fermentation, the carbon content of the products was 0.9%–5.5% higher than that of the consumed sugar. For the purpose of the calculations the carbon content in mycelium was accepted as 0.462.The work was a part of Project No 04.11 CPBP, topic No 2.24 相似文献
47.
Halińska, A. and Lewak, St. 1987. Free and conjugated gibberellins in dormancy and germination of apple seeds.
The presence of gibberellin A4 (GA4 ) was confirmed in partly stratified seeds of apple ( Malus domestica Borb., cv. Antonówka) by mass spectrometry of the methyl ester. Levels of free and conjugated gibberellins A4+7 and A9 changed during drying of mature seeds, during cold and warm stratification, as well as during germination of dormant and non-dormant embryos. The temporary rise in GA4+7 during cold stratification and during the culture of dormant embryos as well as the lack of it under conditions of warm stratification, allowed us to postulate a role for GA4+7 in the removal of dormancy. In addition, GA9 was absent in dormant embryos and increased during cold stratification and during the culture of non-dormant embryos. This suggests the involvement of GA9 , in induction of normal development of the seedling. The equivalence between changes in free and conjugated GAs suggests that formation and hydrolysis of conjugates are involved in the control of the physiologically active levels of free GA4+7 and GA9 . 相似文献
The presence of gibberellin A
48.
49.
Anna Chrtková 《Plant Systematics and Evolution》1987,155(1-4):307-309
A new species,Lotus digii, has been found in Morocco growing on the coastal sandy soils. Further localities are from Algeria and Egypt. It should be expected also in Libya. 相似文献
50.