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101.
Héctor F. Terenzi João A. Jorge José E. Roselino Renato H. Migliorini 《Archives of microbiology》1979,123(3):251-258
The inability to synthesize cyclic AMP drastically affects the nutritional metabolism of Neurospora crassa. The adenylyl cyclase-less mutant cr-1 (crisp) did not utilize several carbon sources, including glycerol, mannitol, arabinose, and casaminoacids. However, in glucose or acetate it grew as well as the wild type. The following evidence suggested that these nutritional deficiencies were a direct result of the cr-1 mutation: (i), in crosses to wild type they segregated together with the crisp morphological marker; (ii), cyclic AMP added to the cr-1 mutant growth medium overcame the nutritional deficiencies; (iii), the cyclic AMP effect was specific for the crisp mutant, for it was not observed with the wild type, nor with a spontaneous glycerol-utilizing cr-1 strain. 相似文献
102.
Summary Chromosome 17ps was identified in the mother and daughter but not the father of a normal family with no history of congenital abnormality. In addition to G-band and Ag-NOR staining, previously used to study this abnormality, we applied N-band and C-band techniques. Our results showed that 17ps has no demonstrable ribosomal cistron or constitutive heterochromatin. 相似文献
103.
A benzene extract of the trunk of an Aniba species (Lauraceae) contained benzyl benzoate, benzyl salicylate, sitosterol and the neolignans (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran (burchellin); (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,3aR)-3a-allyl-5,7-dimethoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,5S)-5-allyl-5-methoxy-3-methyl-2-veratryl-2,3,5,6-tetrahydro-6-oxo-benzofuran; (2R,3R)-7-methoxy-3-methyl-5-propenyl-2-veratryl-2,3-dihydrobenzofuran; rel-(1R,5R,6R,7R,8S)-1-allyl-8-hydroxy-3-methoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene (guianin); rel-(1S,5S,6S,7R,8R)-1-allyl-8-hydroxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1S,5S,6S,7R,8R)-8-acetoxy-1-allyl-3-hydroxy-5-methoxy-7-methyl-4-oxo-6-piperonyl-bicyclo[3,2,1]oct-2-ene; rel-1S,5S,6S,7R,8R)-8-acetoxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1R,5S,6R,7R)-1-allyl-3-methoxy-7-methyl-4,8-dioxo-6-piperonylbicyclo[3,2,1]oct-2-ene. 相似文献
104.
Analysis of Dioscorea deltoidea tissue cultures grown in the presence of 2,4-D, indole-3-butyric acid, isopentenyladenine, benzyladenine and GA singly and in combination showed that the medium with 2,4-D most consistently favored diosgenin production. GA and high benzyladenine concentrations were toxic. 相似文献
105.
Summary A tri-lamellar body has been observed either near or adjacent to the crosswalls in 16 out of 20 different isolates ofAnabaena examined in thin sections. These bodies appear to consist of three discoid lamellae approximately 0.3 m in diameter. The outer lamella (closest to the plasma membrane) is separated from the middle lamella by a 12 nm space and is about 8 nm in thickness. The middle and inner lamellae, spaced about 8 nm apart, are approximately 8 nm in thickness. Electron dense granules, interpreted to be -granules, are associated with the inner lamella. In different species, osmiophilic lines 3 nm wide were observed. The osmiophilic lines run at right angles to the lamellae, either between the outer and middle lamellae, between the middle and inner lamellae or between all three lamellae. In some species, osmiophilic lines are absent. Up to six tri-lamellar bodies have been observed in median longitudinal sections. Pores 20 nm in diameter and 60 nm apart were observed in layer 2 of the cell wall of all the species ofAnabaena examined. All species which had tri-lamellar bodies also had wall pores closely associated with the bodies. Wall pores were also observed in four species lacking tri-lamellar bodies. The possible role of these structures is discussed. 相似文献
106.
Carol M. Warner Ruth M. Graves Carla M. Tollefson Mary Jo F. Schmerr Thomas J. Stephens Carmen F. Merryman Paul H. Maurer 《Immunogenetics》1976,3(1):337-348
The immune response of allophenic mice of type C57BL/6(A × SJL) F1 to GL administered in complete Freund's adjuvant was tested. Control mice of the three strains C57BL/6, A, and SJL are all nonresponders to this antigen. However, the F1 generations of C57BL/6 × A, C57BL/6 × SJL, and A × SJL were all responders to the antigen, so that the complementarity of at least two genes is confirmed. The allophenic mice showed no further complementation beyond the F1 generation, a result which may argue against the possibility that more than two genes control the response to GL in these mouse strains. Characterization of the allophenic mice over several months showed that they exhibit chimeric drift, both in their coat color and in peripheral white blood cell population. There is no apparent correlation of coat color to the lymphocyte composition of the mice at any one time. The mice are true chimeras, since killing of the two populations of white blood cells with two different anti-H-2 sera produced a 100 percent killing. The immune response of individual allophenic mice to GL showed a good correlation to the number of A × SJL lympho-cytes in the animal.Abbreviations used in this paper are GL
an amino acid polymer of 57 %l-glutamic acid, 38%l-lysine, and 5%l-phenylalanine
- GLT15
an amino acid polymer ofl-glutamic acid,l-lysine, and 15 %l-tyrosine
- (T,G)-A-L
an amino acid polymer having a polylysine backbone with side chains of polyd-l-alanine, terminating in short sequences of tyrosine and glutamic acid
- GAT10
an amino acid polymer of 60%l-glutamic acid, 30%l-alanine, and 10%l-tyrosine
- GLA5
an amino acid polymer of 57%l-glutamic acid, 38%l-lysine, and 5%l-alanine
- DNP
2,4 dinitrophenyl
- BGG
bovine gamma globulin
- FCS
fetal calf serum
- PWBC
peripheral white blood cell
- SWBC
spleen white blood cell
- T cell
thymus-derived lymphocyte
- B cell
bone marrow-derived lymphocyte 相似文献
107.
A microplate-microtubule array was observed in Anabaena sp. (B-378). This structure consists of an arched plate, about 8 nm thick, and various microtubules, 12 nm in diameter and 50 nm long, arranged in rows. The microtubules project at right angles from one side of the plate into the cytoplasm or towards the plasma membrane. Up to twelve microplate-microtubule arrays were observed in a single section of a cell.Microfilaments, about 2.8 nm in diameter and of undetermined length, were observed in four isolates of Anabaena. The microfilaments were always found in bundles, which varied in size, up to 0.63 m across and 0.91 long.Microtubules, 10 nm in diameter and about 150 nm in length, were observed associated with one facet of polyhedral bodies in 8 out of 20 isolates of Anabaena. The microtubules occurred in groups of up to 20 or more, and were always oriented with the long axis parallel to a facet of a polyhedral body. In cross section, the microtubules had an electron transparent lumen 5 nm wide and a wall 2.5 nm thick.These structures are compared to previously deseribed microtubules and microfilaments. 相似文献
108.
109.
Fitness of Allozyme Variants in DROSOPHILA PSEUDOOBSCURA. I. Selection at the PGM-1 and ME-2 Loci 总被引:4,自引:3,他引:1 下载免费PDF全文
We have studied in Drosophila pseudoobscura the effect of allozyme variation on seven fitness components: female fecundity, egg hatchability, egg-to-adult survival under near-optimal and under competitive conditions, rate of development under near-optimal and under competitive conditions, and mating capacity of males. Three genotypes at each of two loci, Pgm-1 and Me-2, have been studied in various combinations. These two loci are highly polymorphic in natural populations of D. pseudoobscura. Statistically significant differences involving one or more genotypes exist for all components of fitness. No single genotype is best for all fitness components; rather the relative fitnesses of genotypes are reversed when different parameters are considered, or when they are studied in different environmental conditions. Also, the average egg-to-adult survival and rate of development are better when different genotypes are reared together than when they occur in pure culture. Four different modes of selection have been uncovered by our experiments. These forms of selection may account for the persistence of the two allozyme polymorphisms in nature, and for previously observed seasonal fluctuations of the allelic frequencies in natural populations. 相似文献
110.