title: Disruption of the fatty acid Delta6-desaturase gene in the oil-producing fungus Mortierella isabellina by homologous recombination.
abstract: The gamma-linolenic acid-producing fungus Mortierella isabellina 6-22 is an important industrial strain. To clarify the biosynthetic pathways for polyunsaturated fatty acids in this strain, a disruption vector pD4MI6, including 5' and 3' regions of the fatty acid Delta(6)-desaturase open reading frame as homologous recombination elements and the Escherichia coli hygromycin B (HmB) phosphotransferase gene (hph) as selectable marker, was successfully constructed. Following transformation of pD4MI6 into the hygromycin B-sensitive recipient strain M. isabellina 6-22-4, a Delta(6)-desaturase gene-defective mutant strain was selected that was unable to produce gamma-linolenic acid as determined by gas chromatography and molecular analysis. The morphology and physiology of the mutant, such as colony shape, color, and growth rate, were changed dramatically compared with that of strain M. isabellina 6-22-4.
authors.affiliation: College of Life Science, Nankai University, 300071, Tianjin, People's Republic of China.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Zhang
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wei
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
authors.forename: Xue
authors.initials: X
authors.lastname: Chen
authors.forename: Laijun
authors.initials: L
authors.lastname: Xing
mesh_terms: D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis; D005800:Genes, Fungal; D005822:Genetic Vectors; D050602:Linoleoyl-CoA Desaturase / Q000235:genetics*; D020094:Mortierella / Q000201:enzymology* / Q000235:genetics*; D016296:Mutagenesis; D010957:Plasmids / Q000235:genetics; D011995:Recombination, Genetic; D014170:Transformation, Genetic
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal; D005231:Fatty Acids, Unsaturated; D050602:Linoleoyl-CoA Desaturase