Improvement of the fatty acid composition of an oil-producing filamentous fungus, Mortierella alpina 1S-4, through RNA interference with delta12-desaturase gene expression.
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.
Takeno
Seiki
S
Laboratory of Fermentation Physiology and Applied Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Sakuradani
Eiji
E
Tomi
Akiko
A
Inohara-Ochiai
Misa
M
Kawashima
Hiroshi
H
Ashikari
Toshihiko
T
Shimizu
Sakayu
S
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
D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D012331:RNA, Fungal; D016718:Arachidonic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase