Changes in fatty acid composition of phospholipids and triacylglycerols after cold-acclimation of an aestivating insect prepupa
Changes in fatty acid composition of phospholipids and triacylglycerols after cold-acclimation of an aestivating insect prepupa
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DOI：
10.1007/s003600050165
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发表时间：
1998-08-01
期刊：
影响因子：
--
通讯作者：
Simek, P
中科院分区：
文献类型：
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作者：
Kostal, V;Simek, P
地中海北极星蛾Cymbalophora pudica在夏季滞育（夏眠）中度过炎热的春季和夏季。虽然他们的耐寒性（1天暴露于零度以下的温度后的生存）是相对较低的，它可能会适度增强先前的冷驯化在零度以上的温度下降。在这项研究中，磷脂和三酰甘油的脂肪酸进行了分析，在五个不同的组织（体壁，中肠，脂肪体，丝腺和脑）解剖从冷驯化和控制夏眠包皮。五种最丰富的脂肪酸（油酸、棕榈酸、硬脂酸、亚油酸和α-亚麻酸），通常存在于两种脂肪组分和所有五种组织中，代表了鳞翅目昆虫典型的脂肪补充。各组织的脂肪酸谱各不相同，对冷驯化的反应也具有组织特异性。在体壁、脂肪体和丝腺中，不饱和脂肪酸的比例在冷驯化后有中度但显著的增加。此外，在中肠和大脑的三酰甘油中发现了脂肪酸谱的显著重排，而不改变不饱和/饱和比。脂肪体甘油三酯的不饱和度增加所引起的流动性增强的适应价值尚不清楚，因为这种昆虫在夏眠期间不利用脂肪能量库。最小的能力，改变膜结合脂肪酸被发现在所有组织中，除了中肠，其中的不饱和/饱和比的磷脂略有增加后，冷驯化。C.在低温下改变膜脂组成的能力较低，这与C.在冷驯化过程中，提高其抗寒性。这可能是昆虫冷适应过程中膜脂结构变化的间接支持。
Prepupae of the Mediterranean arctiid moth Cymbalophora pudica spend hot spring and summer months in a summer diapause (aestivation). Although their cold-hardiness (survival after 1-day exposure to subzero temperatures) is relatively low, it may be moderately enhanced by prior cold acclimation at decreasing above-zero temperatures. In this study, fatty acids of phospholipids and triacylglycerols were analysed in five different tissues (body wall, midgut, fat body, silk glands and brain) dissected from both cold-acclimated and control aestivating prepupae. The five most abundant fatty acids (oleic, palmitic, stearic, linoleic and alpha-linolenic), found generally in both lipidic fractions and all five tissues, represent a typical fatty complement of Lepidoptera. The fatty acid profiles of individual tissues differed from each other and the response to cold acclimation was also tissue-specific. Moderate but significant increases in the proportion of unsaturated fatty acids after cold acclimation were observed in triacylglycerols of the body wall, fat body and silk glands. Additionally, significant rearrangements of fatty acid profiles were found in triacylglycerols of midgut and brain, without changing the unsaturation/saturation ratio. The adaptational value of enhanced fluidity of fat body triacylglycerols caused by their increased unsaturation remains unclear, because the lipidic energy depots are not utilized during aestivation of this insect. Minimal capacity to alter the membrane-bound fatty acids was found in all tissues except midgut, where the unsaturation/saturation ratio of phospholipids slightly increased after cold acclimation. A low ability to alter the composition of membrane lipids in response to low temperature, correlates well with the low capacity of C. pudica prepupae to enhance their cold-hardiness during cold-acclimation. This may be regarded as indirect support for the membrane lipid restructuring in insect cold adaptation.