Abstract
The unicellular red alga Cyanidioschyzon merolae 10D has simple cell structure, which contains one nucleus, one mitochondrion and one plastid. C. merolae is considered to be a model organism to analyze the basic construction of eukaryotic cells, and it is indispensable to develop transformation techniques to facilitate functional genomics.
Previously we demonstrated that a lesion in the URA5.3 gene was repaired by the introduction of wild type URA5.3 gene in a homologous recombination dependent manner. In this study, we constructed a URA5.3 gene in which the URA3 portion was substituted by the URA3 of Galdieria sulphuraria, a related red alga, which prevents the recombinational transformation. Using plasmids containing this marker gene, plasmid constructs were stably retained in C. merolae in some cases, which may indicate the plasmid DNA replication in C. merolae cells.
