Long-Term XXXX and Caloric Restriction Caused by Low- or High-Density Husbandry Have Differential Effects on @entity3392 Postembryonic Development, Somatic Growth, Fat Accumulation and Reproduction.

@entity28 @entity7298 @entity1184 @entity1373 @entity448 @entity209 @entity3392
UNASSIGNED: In recent years, the @entity3392 ( @entity3392 ) has emerged as an alternative vertebrate model for energy homeostasis and @entity209 , including @entity28 and @entity448 . It has been shown that @entity28 ( @entity28 ) in @entity3392 shares multiple pathophysiological features with @entity28 in mammals. However, a systematic and comprehensive analysis of the different pathways of energy expenditure in @entity28 and starved fish had been missing thus far. Here, we carry out long-term ad libitum feeding ( @entity7298 ) and caloric restriction studies induced by low- or high-density husbandry, respectively, to investigate the impact of caloric intake on the timing of scale formation, a crucial step of postembryonic development and metamorphosis, and on somatic growth, body weight, fat storage and female reproduction. We show that all of them are positively affected by increased caloric intake, that middle-aged fish develop severe @entity28 , and that the body mass index (BMI) displays a strict linear correlation with whole-body triglyceride levels in adult @entity3392 . Interestingly, juvenile fish are largely resistant to @entity28 , while BMI and triglyceride values drop in aged fish, pointing to aging-associated anorexic effects. Histological analyses further indicate that increased fat storage in white adipose tissue involves both @entity1373 and @entity1184 of adipocytes. Furthermore, in ovaries, caloric intake primarily affects the rate of oocyte growth, rather than total oocyte numbers. Finally, comparing the different pathways of energy expenditure with each other, we demonstrate that they are differentially affected by caloric restriction / high-density husbandry. In juvenile fish, scale formation is prioritized over somatic growth, while in sexually mature adults, female reproduction is prioritized over somatic growth, and somatic growth over fat storage. Our data will serve as a template for future functional studies to dissect the neuroendocrine regulators of energy homeostasis mediating differential energy allocation.
