The inserts of pBS–pds S or pBS–pds L with the ble added 5′ or 3′ to the mutated pds selection marker gene, were extracted using restriction endonucleases and these linear DNA fragments were used to successfully transform H. pluvialis at frequencies similar to circular plasmids (Table 2). Norflurazon-resistant colonies were isolated and analyzed. The mutated DNA genotype was confirmed by PCR and DNA sequencing (data not shown). The transgene inserted was confirmed by PCR of the full-length CDS (Fig. 3) and the full PsaD–ble cassette (data not shown).