title: Improvement of the fatty acid composition of an oil-producing filamentous fungus, Mortierella alpina 1S-4, through RNA interference with delta12-desaturase gene expression.
abstract: An oleaginous fungus, Mortierella alpina 1S-4, is used commercially for arachidonic acid production. Delta12-Desaturase, which desaturates oleic acid (18:1n-9) to linoleic acid (18:2n-6), is a key enzyme in the arachidonic acid biosynthetic pathway. To determine if RNA interference (RNAi) by double-stranded RNA occurs in M. alpina 1S-4, we silenced the Delta12-desaturase gene. The silenced strains accumulate 18:2n-9, 20:2n-9, and Mead acid (20:3n-9), which are not detected in either the control strain or wild type strain 1S-4. The fatty acid composition of stable transformants was similar to that of Delta12-desaturation-defective mutants previously identified. Thus, RNAi occurs in M. alpina and could be used to alter the types and relative amounts of fatty acids produced by commercial strains of this fungus without mutagenesis or other permanent changes in the genetic background of the producing strains.
authors.affiliation: Laboratory of Fermentation Physiology and Applied Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Seiki
authors.initials: S
authors.lastname: Takeno
authors.forename: Eiji
authors.initials: E
authors.lastname: Sakuradani
authors.forename: Akiko
authors.initials: A
authors.lastname: Tomi
authors.forename: Misa
authors.initials: M
authors.lastname: Inohara-Ochiai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawashima
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ashikari
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
mesh_terms: D016718:Arachidonic Acid / Q000096:biosynthesis; D003470:Culture Media; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000032:analysis* / Q000096:biosynthesis; D020868:Gene Silencing; D007218:Industrial Microbiology / Q000379:methods; D020094:Mortierella / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference; D012331:RNA, Fungal / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D012331:RNA, Fungal; D016718:Arachidonic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase