Characterization of Neurospora crassa mutants isolated following repeat-induced point mutation of the beta subunit of fatty acid synthase.
Neurospora crassa cel-2 mutants were isolated following repeat-induced point mutation using part of the gene encoding beta-fatty acid synthase. These mutants are phenotypically less leaky than cel-1, which has a defective alpha-fatty acid synthase. The cel-2 mutant had a strict fatty acid (16:0) requirement for growth, and synthesized less fatty acid de novo than cel-1. Unlike cel-1, cel-2 has impaired fertility, and homozygous crosses are infertile, suggesting a low but strict requirement for fatty acid synthesis during sexual development. Like cel-1, cel-2 synthesized unusually high levels of the polyunsaturate 18:3(Delta9,12,15), and elongated 18:2(Delta9,12 )and 18:3(Delta9,12,15 )to 20:2(Delta11,14) and 20:3(Delta11,14,17), respectively. These fatty acids are not synthesized by wild-type, except following treatment with cerulenin (a fatty acid synthase inhibitor), demonstrating that inhibition of fatty acid biosynthesis results in a relative increase in both fatty acid desaturation and elongation activity.
Goodrich-Tanrikulu
M
M
United States Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Albany, CA 94710, USA.
Jacobson
D J
DJ
Stafford
A E
AE
Lin
J T
JT
McKeon
T A
TA
D000483:Alleles; D064429:Fatty Acid Synthases / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism; D016296:Mutagenesis; D009492:Neurospora crassa / Q000235:genetics*; D010641:Phenotype; D017354:Point Mutation; D014170:Transformation, Genetic
D005227:Fatty Acids; D064429:Fatty Acid Synthases