中国生物工程杂志

Abstract：The purpose of this study was to compare the difference between transgene expressions driven by homologous duplicated carbonic anhydrase(DCA)promoter and foreign CaMV35S promoter in the unicellular green alga, Dunaliella Salina. We introduced the CaMV35S promoter-bar construct and DCA promoter-bar construct into D.Salina by a Backon 2000 electroporation system. After the repeated selection with the PPT of 3mg/L, 3 PPT-resistant phenotype transformants were isolated from the CaMV-bar and DCA-bar pools of transformants of D. Salina, respectively. The results of PCR and sequencing showed that bar genes were stablely integrated into the genome of D.Salina, and Sorthern bolt showed the number of transgene copy had no significant difference between both promoters. Semi-quantitive RT-PCR indicated that the mRNA levels of bar gene were higher in DCA-bar transformants than the CaMV-bar transformants, and can be increased with the induction of high salt in DCA-bar transformants while the CaMV-bar transformants showed no change with the salt induction. The analysis of growth rate of transformants showed DCA-bar transformants achieved the log stage faster than the CaMV-bar transformants. It is concluded that the homologous promoters have more advantages than the foreign promoter in the transgenic D.Salina.