Abstract
The unicellular red alga Cyanidioschyzon merolae 10D shows simple cell structure, containing one nucleus, one mitochondrion and one plastid. In order to use this organism as a model cell, it is indispensable to develop transformation techniques to facilitate functional genomics.
URA5.3 gene of C. merolae is the fusion gene of orotate phosphoribosyltransferase (URA5) and orotidine-5'-phosphate decarboxylase (URA3). To use it as a selection marker, we previously constructed a fusion gene of URA5.3, whose URA3 region was substituted to that of Galdieria sulphuraria, other unicellular red alga. Adjacent regions of CfxQ gene, a regulator of RubisCO, were connected to the marker to construct a plasmid for disruption of CfxQ gene. Uracil prototroph strains were obtained by transformation using the linearized plasmid. PCR analyses showed the marker was inserted into genome of the transformants by the single-crossover.
