Utility of the pat gene as a selectable marker gene in production of transgenic Dunaliella salina

Background: The objective of this study was to develop an efficient selectable marker for transgenic Dunaliella salina. Results: Tests of the sensitivity of D. salina to the antibiotic chloramphenicol and the herbicide Basta® showed that cells (1.0 × 10 cells/ml) treated with 1000 or 1500 μg/ml chloramphenicol died in 8 or 6 days, respectively, whereas D. salina cells (1.0 × 10 cells/ml) treated with 5, 10, 20, or 40 μg/ml Basta® died in 2 days. Therefore, D. salina is more sensitive to Basta® than to chloramphenicol. To examine the possibility of using the phosphinothricin N-acetyltransferase (pat) gene as a selectable marker gene, we introduced the pat genes into D. salina with particle bombardment system under the condition of helium pressure of 900 psi from a distance of 3 cm. PCR analysis confirmed that the gene was stably inserted into the cells and that the cells survived in 5 μg/ml Basta®, the medium used to select the transformed cells. Conclusions: The findings of this study suggest that the pat gene can be used as an efficient selectable marker when producing transgenic D. salina.