Venugopal K J, Kumar D
Department of Zoology, Banaras Hindu University, Varanasi, India.
Comp Biochem Physiol C Toxicol Pharmacol. 2000 Sep;127(2):153-63. doi: 10.1016/s0742-8413(00)00143-2.
Investigations were carried out to determine the role of juvenile hormone (JH) and 20-hydroxy ecdysone in the synthesis and uptake of vitellogenins, which were earlier identified, purified and characterised, in Dysdercus koenigii. The concentration(s) of vitellogenin(s) in fat body, haemolymph and that of vitellin(s) in ovary were significantly lower after chemical allatectomy at eclosion. In addition, at 70 h after emergence, chemical allatectomy reduced ovarian vitellin concentration, but vitellogenin levels remained normal in the fat body and haemolymph. The haemolymph vitellogenins were not incorporated into oocytes in such insects. Administration of JH-III at 20 h after allatectomy restored vitellogenin levels in the fat body and haemolymph, but the ovary failed to incorporate the available vitellogenins from haemolymph in such insects. However, when JH-III was administered twice, one at 20 h and then at 70 h after allatectomy, vitellogenin concentrations in fat body and haemolymph and also vitellin concentrations in ovary approached control levels. It is suggested that JH has two separate roles, one in vitellogenin synthesis and the other in uptake. 20-hydroxy ecdysone had no apparent role in either vitellogenin synthesis or uptake in D. koenigii.
开展了相关研究，以确定保幼激素（JH）和20-羟基蜕皮酮在红蝽（Dysdercus koenigii）中卵黄原蛋白合成与摄取过程中的作用，这些卵黄原蛋白此前已被鉴定、纯化和表征。羽化时进行化学去咽侧体手术后，脂肪体和血淋巴中卵黄原蛋白的浓度以及卵巢中卵黄磷蛋白的浓度显著降低。此外，羽化后70小时，化学去咽侧体手术降低了卵巢中卵黄磷蛋白的浓度，但脂肪体和血淋巴中的卵黄原蛋白水平仍保持正常。在这类昆虫中，血淋巴中的卵黄原蛋白不会被纳入卵母细胞。在去咽侧体手术后20小时施用JH-III可恢复脂肪体和血淋巴中卵黄原蛋白的水平，但在这类昆虫中，卵巢无法摄取血淋巴中可用的卵黄原蛋白。然而，当在去咽侧体手术后20小时和70小时分别施用一次JH-III时，脂肪体和血淋巴中卵黄原蛋白的浓度以及卵巢中卵黄磷蛋白的浓度接近对照水平。研究表明，JH有两个独立的作用，一个是在卵黄原蛋白合成中，另一个是在摄取中。20-羟基蜕皮酮在红蝽的卵黄原蛋白合成或摄取过程中均无明显作用。
