Low-temperature exposure prolongs lifespans and changes lipid metabolism but the relationship between longevity and lipids is largely unknown. Here, we examine the relationship between longevity and lipid metabolism at low temperatures (20 °C and 15 °C) compared with a 25 °C control. Life parameters, fatty acid composition, and transcriptome changes were analyzed in the monogonont rotifer Brachionus koreanus. In vivo life-parameter data indicate that lifespan and fecundity exhibit opposite correlations at low temperatures. The amount of total fatty acids decreased significantly at low temperatures but areas stained with Nile red increased at 15 °C compared with the control. From RNA-seq–based transcriptional analysis, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway-enrichment analysis were conducted. GO analysis shows that telomeres were positively regulated at low temperatures. KEGG pathway-enrichment results indicate that gene expression involved in lipid metabolism was activated with increased glycerol and/or choline synthesis at low temperatures. We suggest that reduced reproductive rates are associated with a decrease of lecithin, which is involved in the conversion of glycerol to triacylglycerol in response to low temperatures by lowering the temperature of body fluid.

低温暴露可延长寿命并改变脂质代谢，但寿命和脂质之间的关系尚不清楚。在这里，我们检查了与25°C对照相比，低温（20°C和15°C）下长寿和脂质代谢之间的关系。分析了生活在轮虫轮枝Brachionus koreanus中的生活参数，脂肪酸组成和转录组变化。体内寿命参数数据表明寿命和繁殖力在低温下表现出相反的相关性。与对照相比，在低温下总脂肪酸的含量显着降低，但在15°C时尼罗红染色的区域增加。通过基于RNA序列的转录分析，进行了基因本体论（GO）和《京都议定书基因与基因组百科全书》（KEGG）途径富集分析。GO分析表明，端粒在低温下受到正调控。KEGG途径富集的结果表明，在低温下，甘油和/或胆碱合成的增加激活了参与脂质代谢的基因表达。我们建议生育率降低与卵磷脂的减少有关，