Lorenz Matthias W, Anand Anurag N
Department of Animal Ecology I, University of Bayreuth, Bayreuth, Germany.
Arch Insect Biochem Physiol. 2004 Jul;56(3):110-9. doi: 10.1002/arch.20002.
Age-dependent changes in the fat body composition and aspects of lipogenesis in the free abdominal fat body of female crickets, Gryllus bimaculatus, were studied. Lipid, protein, glycogen, and free carbohydrate content of the fat body, and fat body wet weight increased simultaneously and sharply from day 0 onwards and were doubled/almost doubled by day 2 after adult emergence. Lipogenic activity of the fat body, fat body weight, and the energy stores in the fat body peaked on day 2, except for free carbohydrate, which peaked on day 3. On day 2, the fat body was mainly comprised of lipid (53.8%) and protein (6.6%), while glycogen and free carbohydrate together contributed less than 1% of the fat body wet weight. After peaking, both lipogenesis and energy stores decreased in a synchronous manner. The depletion of the fat body energy stores and the consequent decrease in the fat body weight were concomitant with a fast and massive gain in ovary weight (day 2: 19.5 +/- 1.5 mg; day 4: 332.8 +/- 31.5 mg) due to the vitellogenic oocyte growth that started on day 2. Our data clearly underline the importance of the free abdominal fat body as a source of energy for reproduction in the cricket. Fat body fatty acid synthase activity coincided with lipogenic activity. Adipokinetic hormone inhibits lipid synthesis in the fat body, but treatment of the fat body with adipokinetic hormone in vitro showed no consistent effect on fatty acid synthase activity.
研究了双斑蟋雌性成虫游离腹部脂肪体中脂肪体组成的年龄依赖性变化以及脂肪生成的相关方面。从成虫羽化第0天起，脂肪体的脂质、蛋白质、糖原和游离碳水化合物含量以及脂肪体湿重同时急剧增加，到羽化后第2天增加了一倍/几乎增加了一倍。脂肪体的脂肪生成活性、脂肪体重量以及脂肪体中的能量储存于第2天达到峰值，但游离碳水化合物除外，其在第3天达到峰值。在第2天，脂肪体主要由脂质（53.8%）和蛋白质（6.6%）组成，而糖原和游离碳水化合物合起来占脂肪体湿重的比例不到1%。达到峰值后，脂肪生成和能量储存均同步下降。脂肪体能量储存的消耗以及随之而来的脂肪体重量的减少，与卵巢重量的快速大量增加（第2天：19.5±1.5毫克；第4天：332.8±31.5毫克）同时发生，这是由于从第2天开始的卵黄生成期卵母细胞生长所致。我们的数据清楚地强调了游离腹部脂肪体作为蟋蟀繁殖能量来源的重要性。脂肪体脂肪酸合酶活性与脂肪生成活性一致。脂肪动素抑制脂肪体中的脂质合成，但体外使用脂肪动素处理脂肪体对脂肪酸合酶活性没有一致的影响。
