期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：50
页码：15378-15383
DOI：10.1073/pnas.1514012112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceFood availability in nature changes continually over an organisms lifetime. As such, animals must diligently assess resource availability and appropriately allocate reserves that have been stored during times of feast for reproduction, to abate evolutionary pressures during times of famine. Our findings functionally link the availability of somatic (survival-promoting) and germline (reproduction-promoting) lipids to SKN-1 responses to oxidative and nutrient stress. We have defined this physiological response at the molecular, genetic, and organismal levels and identified a specific signaling system for regulating this process within intact animals. These findings will inform not only laboratory-based studies, but also ecological studies that have long sought to functionally integrate oxidative stress responses (like the SKN-1 pathway) into life-history traits. Animals in nature are continually challenged by periods of feast and famine as resources inevitably fluctuate, and must allocate somatic reserves for reproduction to abate evolutionary pressures. We identify an age-dependent lipid homeostasis pathway in Caenorhabditis elegans that regulates the mobilization of lipids from the soma to the germline, which supports fecundity but at the cost of survival in nutrient-poor and oxidative stress environments. This trade-off is responsive to the levels of dietary carbohydrates and organismal oleic acid and is coupled to activation of the cytoprotective transcription factor SKN-1 in both laboratory-derived and natural isolates of C. elegans. The homeostatic balance of lipid stores between the somatic and germ cells is mediated by arachidonic acid (omega-6) and eicosapentaenoic acid (omega-3) precursors of eicosanoid signaling molecules. Our results describe a mechanism for resource reallocation within intact animals that influences reproductive fitness at the cost of somatic resilience.
