Ohtsu T, Katagiri C, Kimura M T, Hori S H
Department of Zoology, Faculty of Science, Hokkaido University, Japan.
J Biol Chem. 1993 Jan 25;268(3):1830-4.
Triacylglycerols are the major fuel for basal metabolism during the winter in temperate species of the Drosophila melanogaster species group. Differential scanning calorimetry analysis revealed that the transition temperatures of triacylglycerols were lower in diapausing adults than in reproducing ones, and also lower in species or strains adapted to cooler climates than those adapted to warmer climates. These phenomena were correlated to the fatty acid compositions of the triacylglycerols; the proportion of unsaturated fatty acids in the triacylglycerols was higher in the diapausing individuals, and in the species or strains adapted to cooler climates. Furthermore, in the temperate species of the montium species subgroup (D. subauraria, D. biauraria, D. triauraria, and D. rufa), the amount of saturated triacylglycerols was smaller than the value expected on the assumption that fatty acids are randomly distributed in the triacylglycerols, suggesting the nonrandom distribution of unsaturated fatty acids among triacylglycerols. This may facilitate the lowering of the transition temperature of triacylglycerols, and hence may be related to the ability of Drosophila to cope with temperate climates.
在黑腹果蝇物种组的温带物种中，三酰甘油是冬季基础代谢的主要燃料。差示扫描量热分析表明，滞育成虫体内三酰甘油的转变温度低于繁殖期成虫，并且在适应较凉爽气候的物种或品系中也低于适应较温暖气候的物种或品系。这些现象与三酰甘油的脂肪酸组成相关；滞育个体以及适应较凉爽气候的物种或品系中，三酰甘油中不饱和脂肪酸的比例更高。此外，在山地物种亚组（南亚果蝇、双金果蝇、三金果蝇和赤腹果蝇）的温带物种中，饱和三酰甘油的含量低于脂肪酸在三酰甘油中随机分布时预期的值，这表明不饱和脂肪酸在三酰甘油中呈非随机分布。这可能有助于降低三酰甘油的转变温度，因此可能与果蝇应对温带气候的能力有关。
