DietaryS. maltophiliapromotes fat storage by enhancing lipogenesis and ER-LD contacts inC. elegans

Abstract

AbstractDietary and symbiotic bacteria can exert powerful influence on metazoan lipid metabolism. Here, we demonstrate that feedingCaenorhabditis elegans (C. elegans)with the opportunistic pathogenic bacteriaStenotrophomonas maltophilia (S. maltophilia)retards growth and promotes excessive fat storage. Gene expression analysis reveals that dietaryS. maltophiliainduces a lipogenic transcriptional response that includes the SREBP ortholog SBP-1, and fatty acid desaturases FAT-6 and FAT-7. Live imaging and ultrastructural analysis suggest that excess fat is stored in greatly expanded lipid droplets (LDs), as a result of enhanced endoplasmic reticulum-LD interaction. We also report that loss of function mutations incyp-35B1ordpy-9inC. elegansconfers resistance toS. maltophilia.Our work delineates a new model for understanding microbial regulation of metazoan physiology.