The effect of matrix attachment regions (MARs) on foreign gene expression in transgenic plants was studied, The beta-glucuronidase (GUS) gene (uidA) was flanked by the MARs isolated from the genome of maize to form pl...The effect of matrix attachment regions (MARs) on foreign gene expression in transgenic plants was studied, The beta-glucuronidase (GUS) gene (uidA) was flanked by the MARs isolated from the genome of maize to form plant expression vector. The vectors with and without MARs were transferred into tobacco ( Nicotiana tabacum L.) through Agrobacterium-mediated transformation procedure. GUS activity assays indicated that MARs could increase expression level of uidA gene. The mean GUS activity could be increased twofold as compared to that of transformants without MARs, and the highest GUS activity of transformant could reach tenfold. The correspondence between GUS activity and mRNA accumulation was positive and indicated that MARs could improve transcription of foreign gene.展开更多
The paper introduce the measurement of some beam parameters for Hefei Light Source (HLS) by frequency domain technique, which include the betatron tune, average beta function, natural chromaticity, corrected chroinati...The paper introduce the measurement of some beam parameters for Hefei Light Source (HLS) by frequency domain technique, which include the betatron tune, average beta function, natural chromaticity, corrected chroinaticity, and center frequency. Additionally, the measurement of the influence of DC clearing electrodes on the betatron tune shift is also described. Some measurement results are given. The measurement results are compared with the theoretical values and shown to be in good agreement.展开更多
文摘The effect of matrix attachment regions (MARs) on foreign gene expression in transgenic plants was studied, The beta-glucuronidase (GUS) gene (uidA) was flanked by the MARs isolated from the genome of maize to form plant expression vector. The vectors with and without MARs were transferred into tobacco ( Nicotiana tabacum L.) through Agrobacterium-mediated transformation procedure. GUS activity assays indicated that MARs could increase expression level of uidA gene. The mean GUS activity could be increased twofold as compared to that of transformants without MARs, and the highest GUS activity of transformant could reach tenfold. The correspondence between GUS activity and mRNA accumulation was positive and indicated that MARs could improve transcription of foreign gene.
基金Supported by National Important Project on Science-Phase Ⅱ of National Synchrotron Radiation Laboratory
文摘The paper introduce the measurement of some beam parameters for Hefei Light Source (HLS) by frequency domain technique, which include the betatron tune, average beta function, natural chromaticity, corrected chroinaticity, and center frequency. Additionally, the measurement of the influence of DC clearing electrodes on the betatron tune shift is also described. Some measurement results are given. The measurement results are compared with the theoretical values and shown to be in good agreement.
