Journal of Aquaculture Research & Development

Abstract

Identification and Efficient Utilization of Antibiotics for the Development of a Stable Transformation System in Porphyra yezoensis (Bangiales, Rhodophyta)

Megumu Takahashi, Koji Mikami, Hiroyuki Mizuta and Naotsune Saga

Despite the development of transient gene expression in red algae Porphyra species, a stable transformation system has not been stablished in these algae yet. One reason for the difficulty in the transformation is the lack of a way to select transformed cells from the algae. Thus, to identify antibiotics suitable for the selection of stably transformed cells, we tested the gametophyte for sensitivity to 6 antibiotics, ampicillin (Am), kanamycin (Km), hygromycin (Hm), geneticin (G418), chloramphenicol (Cm) and paromomycin (Pm), which are frequently employed as selection agents in the transformation of land plants and microalgae. Sensitivity tests, which were carried out with different concentrations (0-10 mg mL-1) of antibiotics, showed that Hm, G418, Cm and Pm exhibited a lethal effect at more than 1.0 mg mL-1, suggesting the suitability of these four antibiotics for the selection of genetically transformed cells from P. yezoensis gametophytes, while P. yezoensis gametophytes were highly resistant to Am and Km. We also succeeded in reducing the antibiotic concentrations by lowering the pH value and salt concentration using an artificial synthetic medium. Increasing the sensitivity of gametophytic cells to Hm, G418, Cm and Pm in the modified synthetic medium will contribute to establishing a genetic transformation system in P. yezoensis.