Fatty acid auxotrophy in Drosophila larvae lacking SREBP.
SREBPs are membrane bound transcription factors that are crucial for normal lipid synthesis in animal cells. Here, we show that Drosophila lacking dSREBP die before the third larval instar. Mutant larvae exhibit pronounced growth defects prior to lethality, along with substantial deficits in the transcription of genes required for fatty acid synthesis. Compared to wild-type larvae, mutants contain markedly less fatty acid, although its composition is unaltered. Dietary supplementation with fatty acids rescues mutants to adulthood. The most effective fatty acid, oleate, rescues 80% of homozygotes. Rescue by dSREBP requires expression only in fat body and gut. Larvae expressing dSREBP prior to pupariation complete development and are viable as adults even when dSREBP expression is subsequently extinguished. The role, if any, of dSREBP in adults is not yet apparent. These data indicate that dSREBP deficiency renders Drosophila larvae auxotrophic for fatty acids.
Kunte
Amit S
AS
Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas 75390, USA.
Matthews
Krista A
KA
Rawson
Robert B
RB
D000818:Animals; D019587:Dietary Supplements; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D007814:Larva; D008297:Male; D009154:Mutation; D051779:Sterol Regulatory Element Binding Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*
D005227:Fatty Acids; D051779:Sterol Regulatory Element Binding Proteins