Establishment of a Transient Gene Expression System in the Marine Red Alga Porphyra yezoensis

Abstract

The progress of the molecular biological studies on development and environmental response in marine multicellular algae is hindered by the lack of reverse genetic techniques. To overcome this situation, we developed a transient gene expression system in sea red algae Porphyra yezoensis. For the efficient expression, we found the importance of the making an artificial β-glucuronidase (GUS) coding region (PyGUS) whose codon usage had been adapted to that in P. yezoensis and the employing promoters of endogenous genes. We also found a very weak activity of the cauliflower mosaic virus (CaMV) 35S promoter in P. yezoensis cells. Since the efficiency of promoters on the PyGUS expression resembled the mRNA abundance analyzed by RT-PCR, the transient gene expression system established in the present study is useful for promoter analyses in P. yezoensis.