title: A transgene expression system for the marine microalgae Aurantiochytrium sp. KRS101 using a mutant allele of the gene encoding ribosomal protein L44 as a selectable transformation marker for cycloheximide resistance.
abstract: In the present study, we established a genetic system for manipulating the oleaginous heterotrophic microalgae Aurantiochytrium sp. KRS101, using cycloheximide resistance as the selectable marker. The gene encoding ribosomal protein L44 (RPL44) of Aurantiochytrium sp. KRS101 was first identified and characterized. Proline 56 was replaced with glutamine, affording cycloheximide resistance to strains encoding the mutant protein. This resistance served as a novel selection marker. The gene encoding the Δ12-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 conversion of oleic acid (C18:1) to linoleic acid (C18:2) was detected in transformants but not in the wild-type strain.
authors.affiliation: Applied Microbiology Research Center, Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology KRIBB, Jeongeup, Jeonbuk 580-185, Korea.
authors.forename: Won-Kyung
authors.initials: WK
authors.lastname: Hong
authors.forename: Sun-Yeon
authors.initials: SY
authors.lastname: Heo
authors.forename: Baek-Rock
authors.initials: BR
authors.lastname: Oh
authors.forename: Chul Ho
authors.initials: CH
authors.lastname: Kim
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Sohn
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Yang
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Seo
mesh_terms: D000483:Alleles; D000935:Antifungal Agents / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology*; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics; D015870:Gene Expression; D005819:Genetic Markers; D009154:Mutation; D012269:Ribosomal Proteins / Q000096:biosynthesis* / Q000235:genetics; D058009:Stramenopiles / Q000235:genetics / Q000378:metabolism; D019076:Transgenes
chemical_list: D000935:Antifungal Agents; D005819:Genetic Markers; D012269:Ribosomal Proteins; D003513:Cycloheximide