Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara 06110, Türkiye.
Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen 37077, Germany.
Proc Natl Acad Sci U S A. 2024 Jul 16;121(29):e2406194121. doi: 10.1073/pnas.2406194121. Epub 2024 Jul 11.
Animals can alter their body compositions in anticipation of dormancy to endure seasons with limited food availability. Accumulation of lipid reserves, mostly in the form of triglycerides (TAGs), is observed during the preparation for dormancy in diverse animals, including insects (diapause) and mammals (hibernation). However, the mechanisms involved in the regulation of lipid accumulation and the ecological consequences of failure to accumulate adequate lipid stores in preparation for animal dormancy remain understudied. In the broadest sense, lipid reserves can be accumulated in two ways: the animal either receives lipids directly from the environment or converts the sugars and amino acids present in food to fatty acids through de novo lipogenesis and then to TAGs. Here, we show that preparation for diapause in the Colorado potato beetle () involves orchestrated upregulation of genes involved in lipid metabolism with a transcript peak in 8- and 10-d-old diapause-destined insects. Regulation at the transcript abundance level was associated with the accumulation of substantial fat stores. Furthermore, the knockdown of de novo lipogenesis enzymes ( and ) prolonged the preparatory phase, while the knockdown of fatty acid transportation genes shortened the preparatory phase. Our findings suggest a model in which the insects dynamically decide when to transition from the preparation phase into diapause, depending on the progress in lipid accumulation through de novo lipogenesis.
动物可以改变自身的身体组成，以适应食物有限的休眠期，从而度过缺乏食物的季节。在各种动物（包括昆虫[休眠]和哺乳动物[冬眠]）为休眠做准备时，都会观察到脂类储备的积累，主要以三酰甘油(TAG)的形式存在。然而，调节脂类积累的机制以及动物休眠前未能积累足够脂类储备的生态后果仍研究不足。从最广泛的意义上讲，脂类储备可以通过两种方式积累：动物要么直接从环境中获取脂类，要么通过从头合成作用将食物中存在的糖和氨基酸转化为脂肪酸，然后再转化为 TAG。在这里，我们表明，科罗拉多马铃薯甲虫()进入休眠的准备过程涉及到与脂类代谢相关的基因的协调上调，在 8 至 10 日龄的休眠注定的昆虫中达到转录峰。在转录丰度水平上的调节与大量脂肪储存的积累有关。此外，从头合成作用酶（和）的敲低延长了预备阶段，而脂肪酸转运基因的敲低则缩短了预备阶段。我们的研究结果表明，昆虫可以根据从头合成作用积累脂类的进展情况，动态地决定何时从准备阶段过渡到休眠阶段。
