Paper: A transgene expression system for the marine microalga <i>Aurantiochytrium</i> sp. KRS101 using a mutant allele of the gene encoding ribosomal protein L44 as a selectable transformation marker for cycloheximide resistance (2012 Annual Meeting and Exhibition (August 12-16, 2012))

Monday, August 13, 2012

Columbia Hall, Terrace Level (Washington Hilton)

Won-Kyung Hong, Sun-Yeon Heo, Chul Ho Kim, Jung-Hoon Sohn, Akihiko Kondo and Jeong-Woo Seo, Systems and Synthetic Biology Research Center,, Korea Research Institute of Bioscience and Biotechnology (KRIBB),, Jeongeup-si, South Korea

In the present study, the gene encoding ribosomal protein L44 (RPL44) of the oleaginous heterotrophic microalga Aurantiochytrium sp. KRS101 was first identified and characterized. RPL44 has proline as residue 56 imparting sensitivity to the antibiotic cycloheximide. A new genetic system for Aurantiochytrium sp. KRS101 was developed by replacing proline 56 of RPL44 with glutamine (the P56Q mutation), which was resistant to cycloheximide served as a selection marker. The gene encoding the 汁12-fatty acid desaturase of Mortierella alpina, used as a reporter, was successfully introduced into chromosomal DNA of Aurantiochytrium sp. KRS101 via 18S rDNA-targeted homologous recombination. Enzymatic activity converting oleic acid (C18:1) to linoleic acid (C18:2) was detected in the transformant but not in wild-type strain.

P108: A transgene expression system for the marine microalga Aurantiochytrium sp. KRS101 using a mutant allele of the gene encoding ribosomal protein L44 as a selectable transformation marker for cycloheximide resistance