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Pulsed-field gel electrophoresis analysis of the genome of Streptomyces ambofaciens strains 总被引:12,自引:0,他引:12
The genome of four Streptomyces ambofaciens strains from different geographical origins (ATCC15154, DSM40697, ETH9247 and ETH 11317) was analysed by pulsed-field gel electrophoresis (PFGE). The PFGE technique has allowed the study of the extrachromosomal content of these strains and the characterization of their genomic DNA by restriction analyses. Electrophoretic migration of undigested DNA allowed us to detect a 80 kb-length linear molecule with concatemeric forms in S. ambofaciens ATCC15154. These extrachromosomal molecules were shown to be homologous to the circular plasmid pSAM1 (80 kb) suggesting that pSAM1 could exist not only in circular form but also in linear form. In the same way a 45 kb-length linear molecule was detected in S. ambofaciens ETH9427 and ETH11317. In contrast, no extrachromosomal DNA could be detected in S. ambofaciens DSM40697. The analysis of the macrorestriction patterns using the rate-cutting enzymes AseI and DraI indicated a close relationship between the DSM- and ETH- strains. Indeed, three types of restriction patterns were distinguished: while S. ambofaciens ETH9427 and ETH11317 were characterized by the same pattern and share more than 75% of comigrating fragments with the strain DSM40697, S. ambofaciens ATCC15154 exhibited a restriction pattern different from the other three. The total genome sizes of S. ambofaciens ATCC15154, DSM40697, ETH9427 and ETH11317 were estimated to be about 6500, 8000, 8200 and 8200 kb, respectively. 相似文献
115.
传入C纤维的兴奋在中电针“足三里”激活中缝大核中的作用 总被引:6,自引:0,他引:6
The purpose of the present work is to study whether the analgesia of "Zusanli" EA was mainly produced by its noxious effect. The antidromic C waves on N. peroneus communis innervating the area of "Zusanli" point were recorded. When "Zusanli" point was stimulated by trains of stimuli, the amplitude of the antidromic C wave was obviously decreased due to collision with the orthodromic stimulation. It was suggested that EA of "Zusanli" could excite some C fibers. It was observed that when the stimulation intensity reached the threshold of C fiber, the NRM neurons were obviously activated, and when it reached or exceeded the intensity for producing the maximal C wave, the NRM neurons were highly activated. Therefore, EA analgesia is probably produced mainly by its noxious stimulus component, especially carried by C fibers, via a negative feedback mechanism in modulating pain. 相似文献
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R Molina X Filella P Mengual M Prats G Zanon M Daniels A M Ballesta 《The International journal of biological markers》1990,5(1):14-21
MCA serum levels were determined in 27 healthy subjects, 136 with benign pathology (42 breast) and in 289 patients with cancer (247 active). The last group includes 223 patients with breast cancer (96 without metastases, 89 with metastases and 38 no-evidence of disease). CEA and CA15-3 serum levels were determined in all the patients with breast diseases. The mean levels of MCA were 4.7 + 2.4 U/ml in the control group, considering less than 11 U/ml as normal. MCA values were abnormal in 15.4% of patients with benign pathology, mainly in those with liver cirrhosis (8/20) and lung diseases (4/20). In the majority of these cases, the rise was only moderate, lower than 15 U/ml in 97.5% of patients. In malignant diseases, important increments were found in breast cancer (19.8% Mo, 77.5% M1) and ovarian cancer stages III-IV (44.4%). When we compared MCA serum levels with CA15-3 and CEA in breast pathology, a similar specificity was observed: 92.3%, 92.3% and 100% in cases with benign pathology and 92.1%, 94.7%, and 97.4% in NED patients, respectively. MCA and CA15-3 sensitivity was similar in breast cancer without metastases (19.8%) and lower for CEA (16.7%). In patients with breast cancer without metastases, we found a relation between positivity of these tumor markers and prognostic factors (tumor size, nodal involvement). The disease free interval in patients with locoregional breast cancer was shorter in cases with abnormal presurgical levels of some of the tumor markers, but only the difference from MCA was significant (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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This paper examines the principal classes of repetitive DNA of the Toulouse goose (Anser anser) genome. There are four major classes and they are tandem repeats of less than 200 base pairs (bp). The longest repeat (class A) is 190 bp long and starts with a HinfI site. Class B is 43 bp long, commencing with a FokI site. Classes A and B show no extensive homology to DNA sequences held on a current data base (Genbank) but were confirmed to exist as major repeats in another strain of goose, the Emden goose (Anser anser) genome. Classes C and D are 5-bp repeats of 5' GAGAG 3' and 5' GGGAA 3', respectively. The macrosatellites C and D were compared with a current data base (Genbank) and were found to exist in a variety of other organisms as satellites. 相似文献
119.
Plants contain highly divergent actin isovariants 总被引:5,自引:0,他引:5
B G McLean S R Huang E C McKinney R B Meagher 《Cell motility and the cytoskeleton》1990,17(4):276-290
Actin protein isovariants have been identified in animals with distinct cytoplasmic or muscle specific patterns of expression. Analysis of vascular plant actin gene sequences suggests that an even greater diversity should exist within the plant actin protein families, but previous studies on plant proteins have not demonstrated the presence of multiple actin isovariants. Antibodies recognizing a conserved amino-terminal plant actin peptide, a family of plant actin peptides from a variable region, and two monoclonal antibodies to conserved epitopes within animal actins were used to identify isovariants of soybean actin resolved by two-dimensional isoelectric focusing (IEF) sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Approximately six to eight actin isovariants with pI values ranging from 5.1 to 5.8 have been identified from soybean hypocotyls, stems, leaves, and roots with varying amounts of most isovariants present in all four organs. Acidic isovariants were present in much higher levels in leaves and stems. Antisera with lambda-class actin specificity detected a subset of three isovariants in all organs examined. One monoclonal and one antipeptide antisera are shown to react well with a wide variety of plant actin isovariants. Similar patterns of actin isovariants were detected in the distant angiosperms, Arabidopsis, petunia, and maize. It is likely that many of these diverse classes of isovariants have been preserved throughout vascular plant evolution and reflect the ancient diversity within plant actin gene families. The extreme difference among isovariants implies the presence of a complex actin-based cytoskeletal system in plants. 相似文献
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