Reference - Detail
|Author||Rappleye CA, Tagawa A, Le Bot N, Ahringer J, Aroian RV.|
|Title||Involvement of fatty acid pathways and cortical interaction of the pronuclear complex in Caenorhabditis elegans embryonic polarity.|
|Journal||BMC Dev. Biol.|
BACKGROUND:Cell polarity is essential for many decisions made during development. While investigation of polarity-specific factors has yielded great insights into the polarization process, little is known on how these polarity-specific factors link to the basic cellular mechanisms that function in non-polarity aspects of the cell. To better understand the mechanisms that establish embryonic polarity, we investigated genes required for polarity in the one-cell C. elegans embryo that are also required for other non-polarity functions. This has led to the identification of the Pod-class of mutants that are characterized by osmosensitive embryos and defects in anterior-posterior polarity.
RESULTS:Mutation in either of two loci of this class, emb-8 and pod-2, disrupts embryonic polarization and results in osmotically-sensitive embryos. Loss of emb-8, a previously uncharacterized polarity gene, causes mislocalization of PAR-3 and PAR-2 that molecularly mark the anterior and posterior cortices. emb-8 encodes NADPH-cytochrome P450 reductase, a protein supplying electrons to cytochrome P450-family enzymes, some of which catalyze fatty acid modifications. Cloning of the previously characterized polarity gene pod-2 reveals it encodes acetyl-CoA carboxylase, an enzyme that catalyzes the first step in de novo fatty acid synthesis. Depletion of fatty acid synthase, the next enzyme in the biosynthetic pathway, by RNA-interference (RNAi) also causes similar loss of one-cell polarity. Furthermore, pod-2 polarity defects can be rescued by addition of exogenous fatty acids. By following the behavior of the pronucleus in emb-8 and pod-2 mutant embryos, we demonstrate that loss of polarity correlates with impaired interaction between the pronucleus-centrosome complex and the posterior cortex.
CONCLUSIONS:The characterization of emb-8 and pod-2 mutant embryos suggests that the pronucleus-centrosome complex interaction with the cortex plays a direct role in establishing polarity and that fatty acid pathways are important for this polarizing event.
|MeSH||Acetyl-CoA Carboxylase / genetics Acetyl-CoA Carboxylase / physiology Animals Body Patterning / physiology* Caenorhabditis elegans / embryology* Caenorhabditis elegans / enzymology Caenorhabditis elegans / genetics Caenorhabditis elegans / growth & development Cell Polarity / physiology* Embryo, Nonmammalian / embryology Embryo, Nonmammalian / physiology Fatty Acids / metabolism* Fatty Acids / physiology Gene Expression Regulation, Developmental / physiology Gene Expression Regulation, Enzymologic / physiology Genes, Helminth / physiology NADPH-Ferrihemoprotein Reductase / genetics NADPH-Ferrihemoprotein Reductase / physiology Osmotic Pressure|
|DNA material||cDNA library of mixed-stage C. elegans for yeast two-hybrid screening (RDB1864)|