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81.
Twenty-five accessions belonging to the genus Cytisus and allies (Genisteae: Leguminosae), potentially useful for agrosylvopastoral systems in the Mediterranean basin, were analyzed using isoenzymes. The aim was to assess the taxonomic usefulness of these characters at the specific and generic levels, and its value as an aid for the taxonomy. A high level of infrageneric and infraspecific variability was detected. Numerical analysis showed that isoenzymes are useful for the characterization both at the specific and generic levels. The obtained dendrogram supports the generic arrangement proposed by Bisby [(1981) Advances in Legume Systematics, Vol. 1, pp. 409–425], therefore helping to elucidate the difficult taxonomy of the studied species. 相似文献
82.
Plasmid rolling circle replication and its control 总被引:10,自引:0,他引:10
Manuel Espinosa Gloria del Solar Fernando Rojo Juan C. Alonso 《FEMS microbiology letters》1995,130(2-3):111-120
Abstract This review summarises current information on rolling circle replicating plasmids originally isolated from Gram-positive bacteria with a low guanine and cytosine content in their DNA. It focuses on the peculiar biological features of these small, high copy number plasmids that replicate via an asymmetric RC mechanism. The regulation of plasmid copy number is also discussed. 相似文献
83.
Pili of Pasteurella multocida of porcine origin 总被引:1,自引:0,他引:1
Abstract Using electron microscopy, pili with at least two distinct morphologies were observed on strains of Pasteurella multocida isolated from pigs with atrophic rhinitis. Rigid pili were found on 60–80% of all cells observed. These pili had a strong tendency to lie flat along the side of the outer cell membrane of P. multocida and as a result frequently were difficult to see. After growth in vitro, piliated P. multocida cells produced few pili (approx. 3–5 per cell). Heavily piliated cells were occasionally observed. The second type of pili were curly and also were difficult to visualize. Cells from cultures containing piliated cells failed to attach to red blood cells and to immobilized mucus. 相似文献
84.
The energy-transducing ATPase and a low-molecular-weight fraction ofMicrococcus lysodeikticus membranes incorporated14C label fromd-[U-14C]glucose fed to the bacteria in synthetic medium. The specific radioactivity of the sugar portion of the ATPase and low-molecular-weight
fraction was, respectively, 2.65 and 2.88 times that of their amino acids. Glucose and mannose in approximately equimolar
amounts were identified as the main sugars of the glycoprotein ATPase, thus confirming previous structural studies. Glucose,
galactose, and mannose (1:1:2) were identified as the main sugars of the low-molecular-weight glycopeptides. These results
confirm and extend the notion that glycoprotein are constituents of prokaryotic membranes. 相似文献
85.
G. Lynis Dohm Gary R. Beecher Arthur L. Hecker Fernando R. Puente George J. Klain E. Wayne Askew 《Life sciences》1977,21(2):189-197
Experiments were conducted to investigate the influence of endurance exercise training on protein synthesis in skeletal muscle, heart, and liver. Training decreased incorporation of [14C]-leucine into proteins of the stromal fraction of muscle but there was no change in amino acid incorporation into proteins of the sarcoplasmic and myofibrillar fractions. Incorporation of [14C]-leucine into the protein of heart, liver, and plasma was depressed in trained rats compared to untrained rats. The specific radioactivity of [14C]-leucine was similar in tissues of trained and untrained rats and thus the depressed amino acid incorporation represents a decrease in the rate of protein synthesis. These observations demonstrate that the adaptation of muscle protein metabolism to endurance training is quite different than the alterations during work-induced hypertrophy of muscle. The difference in adaptation probably relates to the functional differences between the types of exercise. However depression of protein synthesis in trained rats is a general effect in several tissues and not an effect localized in muscle tissue. 相似文献
86.
The freshwater Cladocera of Sri Lanka has been revised based on the study of over 700 zooplankton samples collected from all habitat types during 1965–1980. The cladoceran fauna is represented by six families; members of the families Polyphemidae, Leptodoridae and Holopedidae are absent. The common temperate genus Daphnia is rare.Sixty-two species have been recorded from Sri Lanka. Of these, five are new records. Remarks on a few species are given with illustrations. The distribution of Cladocera in different types of habitats is discussed. The greatest species diversity was found in ponds. The Sri Lankan fauna is numerically and in species diversity typical of tropical cladoceran fauna. It resembles the southern Indian fauna very closely except for the absence in Sri Lanka of the genera Acroperus and Camptocercus. 相似文献
87.
The F1-ATPase or BF1 factor was purified from Micrococcus lysodeikticus substrain B grown in a synthetic medium in the presence of tritiated amino acids. When analyzed in sodium dodecyl sulfate-7% polyacrylamide gels, the fresh purified preparation contained α, β, γ subunits (referred as the intrinsic subunits) and two other polypeptides (designated as X and component of relative mobility 1.0) whose status as subunits remains to be established. This overall polypeptide composition was similar to that of the F1-ATPase isolated from the same strain grown in complex medium (J. Carreira, J. M. Andreu, M. Nieto, and E. Muñoz., 1976 Mol. Cell. Biochem.10, 67–76). The distribution of 3H-labeled amino acids into purified F1-ATPase and its constituent polypeptides under different stages of growth was used to investigate the biosynthetic relationship between the different polypeptides. The incorporation of amino acids into purified BF1 factor was slower than that of cytoplasmic and other membrane proteins. In isotope-dilution and chase experiments, F1-ATPase showed one of the slowest rates of decay of the incorporated label. These results point out that F1-ATPase of M. lysodeikticus undergoes slower turnover than the overall cytoplasmic and membrane proteins. Pulse and chase experiments allowed us to conclude that the α, β, γ subunits and the components of relative mobility 1.0 are independent with differences in their turnover and therefore do not bear any apparent relation as precursors-products. The two major subunits represent seemingly the “core” of ATPase, the β subunit behaving like the most stable component. On the other hand, the γ subunit appears to be synthesized independently from this α + β complex. 相似文献
88.
Summary Cytogenetic studies on lymphocytes from a girl aged 3 years and 10 months revealed a ring chromosome 15. Several banding methods showed the r(15) chromosome not to have any apparent deletion of the long arm. The silver staining technique for nucleolar organizer regions showed an NOR positive region (band p12). In only a few cells was a chromosome 15 missing. The size of the r(15) was found to be constant. Comparison with 11 previous reported cases in the literature shows that the clinical manifestations in the different patients with ring chromosome 15 are constant although not clinically identifiable and it appears likely to attribute them to a significantly retarded intrauterine and postnatal growth instead of presumed deficiency in the long arm and mosaic configurations. 相似文献
89.
Summary A male patient with an interstitial deletion 13q14q31 is described. Our necropsy findings included a left retinoblastoma and several gross internal malformations. In this paper we reaffirm that band 13q14 is involved in cases of retinoblastoma and we propose, after studying accompanying cases of total or partial long arm trisomies 13, that the loss of specific 13q bands, from 13q14 to 13q31 is responsible for the congenital defects we are describing. 相似文献
90.
The membrane-bound ATPase activity from two substrains ofMicrococcus lysodeikticus, designated as A and B, was inhibited by antibodies raised against the two forms of purified F1-ATPase. Form B of the enzyme, which behaved as a poorer immunogen than form A, also showed less reactivity as an antigen, independent of the physical state of the F1-ATPase form. Antibodies were raised against the two major subunits ( and ) isolated fromM. lysodeikticus F1-ATPase form A, which was the most stable form of the enzyme. Anti-(-subunit) serum strongly inhibited the ATPase activity of membrane-bound ATPase but showed little inhibition of the purified, soluble F1-ATPase. The anti-(-subunit) serum inhibited the soluble F1-ATPase, but to a lesser extent than the membrane-bound enzyme. In any event, the effect of anti- antibodies on the membrane-bound ATPase was smaller than that of anti- antibodies. It was postulated that the subunit ofM. lysodeikticus F1-ATPase plays an essential and regulatory role in the expression of the immunochemical properties of the protein. 相似文献