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31.
The genetic stability of plants regenerated from either mesophyll protoplasts or leaf slices of the F1 hybrid between Lycopersicon esculentum and L. pennellii was assayed by comparing the ploidy level, leaf morphology and isozyme patterns of the regenerants with their somatic parents. Regenerants from protoplasts were predominantly tetraploid, regenerants from leaf slices were predominantly diploid; both classes of regenerants had isozyme patterns identical to those of the parent plant. Callus was analyzed that grew up from cultures containing fused protoplasts from either irradiated or untreated protoplasts of L. esculentum and L. pennellii. The L. pennellii cell line used was 18 months old and could no longer regenerate. Out of 75 calli scored at 3 isozyme loci, 51 were heterozygous at only one or two of the loci. Irradiation of the two parental lines was not necessary to produce fusion products exhibiting asymmetric expression of parental genes.Abbreviations Got-2
glutamate oxaloacetate transaminase-2
- Pgi-1
phosphoglucoisomerase-1
- Pgm-2
phosphoglucomutase-2 相似文献
32.
33.
Experimentally induced lesions of cutaneous leishmaniasis and the effect of concurrent bacterial infection on the development of these lesions were studied in the golden hamster. Male outbred golden hamsters received intradermal injections at the base of the tail with approximately 10(7) promastigotes of Leishmania braziliensis panamensis, or promastigotes combined with Staphylococcus aureus or Pasteurella multocida or both, bacteria only, or sterile Eagle's minimal essential medium (MEME). The size of the resulting lesions was measured at least twice each week. Hamsters were killed at postinoculation Days 6, 13, 20, 27, 41, or 48, and each lesion was measured, aseptically excised, and bisected; half was used for bacteriologic culture and the other half was prepared for light microscopic examination. Lesions resulting from L. b. panamensis alone progressed from initial erythema to a granulomatous nodule and finally to a necrotic granuloma, often capped by a crateriform ulcer. Lesions resulting from a suspension of L. b. panamensis with added S. aureus or S. aureus and P. multocida, were initially larger, more erythemic and contained a greater proportion of neutrophils up to postinoculation Days 14-21 than did lesions resulting from L. b. panamensis alone. Concurrent infections with bacteria such as S. aureus and P. multocida had little effect on the development of ulcerating characteristics of lesions, but when S. aureus was present it appeared to enhance the severity of the early lesions. Between postinoculation Days 14-28, lesions produced by L. b. panamensis, with or without added bacteria had similar developmental progression of sufficient size for optimal testing of antileishmanial compounds. 相似文献
34.
35.
The method of moments, as presented by Isenberg and Dyson (1969; Biophys. J. 9:1337) has been shown to be a reliable way of obtaining the amplitudes and time constants of several simultaneously emitting species, even in the presence of an overlapping excitation. Recent improvements in the method include (a) a component incrementation test for determining the number of relaxations, (b) a procedure, which we call exponential depression, for dramatically improving convergence, and (c) a new algorithm for implementing the method of moments on a digital computer with a high degree of flexibility and efficiency. These improvements, as well as new general theory, are described and tested using both synthetic and real experimental data. Component incrementation consists of examining models with increasing numbers of exponential terms. Given adequate precision, we find that an analysis for N + 1 components, of data that are actually represented by N components, provides the correct amplitudes and time constants plus an N + 1 term with an insignificant amplitude. Exponential depression is a transformation in which the original excitation and fluorescence, E(t) and F(t), are multiplied by exp (-λt), where λ is an arbitrary parameter. While the convolution is invariant to this transformation, the proper choice of λ greatly reduces the number of iterations necessary to obtain the amplitudes and time constants and may even improve their accuracy. In addition, an appendix by John P. Mullooly presents a statistical analysis of the effect of counting error on the method of moments estimates of fluorescence decay parameters, applicable when data are obtained by the monophoton technique. Formulas are derived that give the approximate precision of the decay parameters for the general case of N exponential components, with calculational details for one and two component systems. 相似文献
36.
37.
Hanson GP 《Genetics》1969,63(3):601-609
38.
Metabolism of D-fructose in Aerobacter aerogenes: analysis of mutants lacking D-fructose 6-phosphate kinase and D-fructose 1,6-diphosphatase 总被引:3,自引:1,他引:2
The relative significance of the pathways for the conversion of d-fructose to d-fructose 1,6-diphosphate via d-fructose 1-phosphate or d-fructose 6-phosphate in Aerobacter aerogenes PRL-R3 was assessed by observing growth patterns of mutants lacking either d-fructose 6-phosphate kinase or d-fructose 1,6-diphosphatase. The mutant lacking d-fructose 6-phosphate kinase grew well on d-fructose or glycerol but not on d-glucose, whereas the mutant lacking d-fructose 1,6-diphosphatase grew on d-glucose but not on d-fructose or glycerol. The data indicate that the pathway of d-fructose metabolism is primarily through d-fructose 1-phosphate rather than d-fructose 6-phosphate. 相似文献
39.
Fatty acid synthesis via the citrate cleavage pathway requires the continual replenishment of oxaloacetate within the mitochondria, probably by carboxylation of pyruvate. Malic enzyme, although present in adipose tissue, is completely localized in the cytoplasm and has insufficient activity to support lipogenesis. Pyruvate carboxylase was found to be active in both the mitochondria and cytoplasm of epididymal adipose tissue cells; it was dependent on both ATP and biotin. Alteractions in dietary conditions induced no significant changes in mitochondrial pyruvate carboxylase activity, but the soluble activity was depressed in fat-fed animals. The possible importance of the soluble activity in lipogenesis lies in its participation in a soluble malate transhydrogenation cycle with NAD malate dehydrogenase and malic enzyme, whereby a continual supply of NADPH is produced. Consequently, the pyruvate carboxylase in adipose tissue both generates mitochondrial oxaloacetate for the citrate cleavage pathway and supplies soluble NADPH for the conversion of acetyl-CoA to fatty acid. 相似文献
40.
E. Günther K. Skiebe W. Mante Hagemann P. Metzner K. Gröber Ramshorn Nover F. Scholz Hanson Keppler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1964,34(6-7):292-296
Ohne Zusammenfassung 相似文献