Expression of foreign genes in Dunaliella by electroporation.

An electroporation procedure has been described for introducing plasmid DNA into Dunaliella salina cells. By this procedure, a bulk of plasmid DNA was delivered into the cells and retained for at least 3 d. Reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing analyses indicated that the transcription and pre-mRNA splicing of ble gene (contributing the Zeocin resistance) were detected in the cells as early as 1 h after the electroporation. Individual colonies could retain the resistance to 10 mg/L Zeocin for at least 6 mo. Subsequent Southern blot analysis showed the existence of introduced plasmid DNA inside these colonies. However, most of the cells (approx 90%) lost the resistance in the presence of 5 mg/L Zeocin during subculturing, which was consistent with the observations of both rearranged and episomal plasmid DNA existed in the cells. Nevertheless, the electroporation procedure allows introducing a gene of interest and studying its expression and function in D. salina cells.