Hypoxia coordinates adipocyte hypertrophy andhyperplasia through HlF1aa-ATGL-PPARy pathway enablesrapid and healthy energy storage in grass carp

Animals often face food scarcity in nature. In order to survive, some animals store substantial fat when food is available. However, the physiological mechanism by which they store substantial fat and maintain metabolic health in the short term is poorly understood. Here, using the grass carp (Ctenopharyngodon idellus) as a model, which exhibits remarkable fat storage capacity, we found that adipose tissue responded to energy overload first and expanded through adipocyte hypertrophy and hyperplasia.To understand how successful adaptation to short-term high-energyintake is achieved, we turned to a unique model organism, theherbivorous fish grass carp (Ctenopharyngodon idellus), which exhibitslow lipid requirements yet demonstrates a pronounced capacity forintraperitoneal fat accumulation and shares similarities with mammals in adipose tissue expansion patterns and pathological responses to ovemutrition.