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101.
Setsuzo Tada Katsuya Gomi Katsuhiko Kitamoto Kojiro Takahashi Gakuzo Tamura Shodo Hara 《Molecular & general genetics : MGG》1991,229(2):301-306
Summary Northern blot analysis of glucose-grown and starch-grown mycelia of Aspergillus oryzae R11340 was conducted using the cloned Taka-amylase A (TAA) gene as a probe. The amount of mRNA homologous to the TAA gene was increased when this fungus was grown with starch as a sole carbon source. In order to analyze the induction mechanism, we inserted the Escherichia coli uidA gene encoding -glucuronidase (GUS) downstream of the TAA promoter and introduced the resultant fusion gene into the A. oryzae genome. Production of a functional GUS protein was induced by starch, but not by glucose. When the effects of various sugars on expression of the fusion gene were examined, the results suggested that the expression of the fusion gene was under control of the TAA gene promoter. 相似文献
102.
E. J. Nücken R. B. Henschke F. R. J. Schmidt 《Molecular & general genetics : MGG》1991,229(1):137-146
Summary Tn21-related transposons are widespread among bacteria and carry various resistance determinants at preferential sites, hs1 and hs2. In an in vivo integrative recombination assay it was demonstrated that these hot spots direct the integration of aminoglycoside resistance genes like aadB from Klebsiella pneumoniae and aacAI from Serratia marcescens, in a recA
– background. The maximum required recognition sequence which must be present in both the donor and recipient plasmids is 5 CTAAAACAAAGTTA 3 (hs2). The double-site-specific recombination occurred with a frequency of 10–5–10–6. The resulting structures include not only replicon fusion products but also more complex structures carrying two copies of the donor plasmid or simply the donor gene flanked by hs elements. hs1 and hs2 are thought to act as recognition sites for a trans-acting site-specific recombinase. By the use of Tn21 deletion derivatives, it has been shown that the recombinase is not encoded by Tn21. This new integrative recombination system is involved in the acquisition of new genes by Tn21-related transposons and their spread among bacterial populations. 相似文献
103.
S. R. Malkhosyan Yu. A. Panchenko A. N. Rekesh 《Molecular & general genetics : MGG》1991,225(2):342-345
Summary The mechanism of anaerobic regulation of synthesis of colicins E1, E2, E3, K and D was studied. It was found that anaerobiosis significantly increases expression of the genes for colicins E1, E2, E3, K, and D. Experiments with novobiocin (a DNA gyrase inhibitor) showed that colicin synthesis in minicells and derepressed colicin synthesis in cells are dramatically reduced by relaxation of DNA supercoiling. A good correlation was observed between the levels of colicin synthesis and plasmid DNA supercoiling and the degree of aeration of the cultures. Thus, the regulation of colicin gene expression in response to a change in aeration appears to be mediated by environmentally induced variations in DNA supercoiling. 相似文献
104.
Sarah Jane Gurr Michael J. McPherson Claire Scollan Howard J. Atkinson Dianna J. Bowles 《Molecular & general genetics : MGG》1991,226(3):361-366
Summary A major pathogen of potato plants (Solanum tuberosum) is the potato cyst nematode (Globodera spp.), which induces localized redifferentiation of a limited number of host cells to form a specialized feeding-site termed the syncytium. A novel strategy utilizing the polymerase chain reaction (PCR) was employed to construct a cDNA library from dissected potato roots highly enriched in syncytial material. The library was differentially screened with cDNA probes derived from the infected root tissue from a compatible interaction and from healthy root tissue. Characterization of one gene identified by the library screen indicated an expression pattern that correlated with events in the immediate vicinity of the pathogen after syncytial establishment. The strategy for library construction and screening could be applicable to the study of gene expression in any plant-pathogen interaction in which the limited supply of cells at the interface of the two organisms precludes a more traditional approach. 相似文献
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