Question

there is a mutation in a gene impairing fatty acid synthesis. what enzyme is most likely being affected? how will a defect in fatty acid synthesis affect embryonic development, if at all?!

Answer 1

Gene involved in de novo synthesis of fatty acid is Fatty acid synthases (FAS). Fatty acid synthases will convert acetyl-CoA to fatty acids in the cytoplasm of cells.

The importance of fatty acid synthases is best described in the publication 'Fatty acid synthesis is essential in embryonic development: Fatty acid synthase null mutants and most of the heterozygotes die in utero; PNAS May 27, 2003, 100 (11) 6358-6363.

In this paper, they have proven that FAS null mutant (Fasn-/-)mice were not produced or they died before implantation. FAS heterozygous (Fasn+/-)mutants were ostensibly normal but died in various stages of development. Around 70% of heterozygous individuals died before complete development. It infers the haploid inefficiency of FAS. Only normal FAS homozygous(Fasn+/+) were performed proper embryonic development. They have also worked with providing diet containing a high level of fatty acid to the heterozygous mutants. But it didn't seem to alleviate the problem of haploid inefficiency, highlights the importance of de novo fatty acid synthesizes during embryonic development.