Siu Sylvia Lee

Abstract The nuclear hormone receptor NHR-49, a homolog of mammalian PPARα and HNF4α, is a key transcriptional regulator of nutrition sensing and fatty acid metabolism in Caenorhabditis elegans. Here, we examine the role of NHR-49 in reproduction, including oocyte activation and ovulation. Loss of NHR-49 causes inappropriate oocyte activation and laying of unfertilized oocytes in the absence of sperm, resulting in rapid loss of yolk and stored fat, and drastic shortening of lifespan.

Abstract Fatty acid desaturation is central to metazoan lipid metabolism and provides building blocks of membrane lipids and precursors of diverse signaling molecules. Nutritional conditions and associated microbiota regulate desaturase expression, but the underlying mechanisms have remained unclear. Here, we show that endogenous and microbiota-dependent small molecule signals promote lipid desaturation via the nuclear receptor NHR-49/PPARα in C. elegans.