FG 526: Nuclear Gene Targeting in Chlamydomonas

By means of a model gene we have shownfor Chlamydomonas reinhardtii that by application of single stranded DNA, targeted modification of nuclear genes is more efficient than with double stranded DNA. In addition, non-homologous DNA-Integration is greatly suppresses. These findings open the possibility of silencing or modification of any selected gene in green algae. During the next three years we intend to optimize this "Gene Targeting System" and make it applicable especially for weakly expressed genes. To make the rekombination process more efficient we will over-express some genes that are involved in recombination processes from Streptomyces rimosus, Ps. aeruginosa or Chlamydomonas itself or add purified recombination proteins to ssDNA during transformation.