Distribution of ovary ecdysteroidogenic hormone I in the nervous system and gut of mosquitoes
Distribution of ovary ecdysteroidogenic hormone I in the nervous system and gut of mosquitoes
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DOI：
10.1093/jis/1.1.3
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发表时间：
2001-01-01
期刊：
影响因子：
--
通讯作者：
Cao, Chun
中科院分区：
文献类型：
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作者：
Brown, Mark R.;Cao, Chun
取食天蛾五龄幼虫时，当保幼激素分泌停止时，保幼激素酯酶（JHE）活性随着幼虫体重的增加而逐渐增加。超过临界重量的天蛾幼虫饥饿会抑制 JHE 的峰值水平，但不会延迟幼虫离开植物寻找化蛹地点时进入游走阶段的时间。这表明 JHE 的峰值水平对于正常的变态时间可能并不重要。饥饿的幼虫正常化蛹，表明 JHE 峰值对于形态正常的化蛹来说不是必需的。在幼虫达到临界体重（对于我们的天蛾品系为6.0至6.5克）后立即开始用选择性JHE抑制剂O-乙基-S-苯基磷酰胺硫醇（EPPAT）对幼虫进行治疗，延迟了进入游荡阶段的时间。相比之下，对体重超过 8.0 克的幼虫进行 EPPAT 处理对随后开始游走的时间没有影响。因此，尽管正常的游走时间并不需要 JHE 达到峰值水平，但它需要低至中等水平的 JHE，直到幼虫达到约 8.0 克的重量。 卵巢蜕皮类固醇激素 I (OEH I) 是雌性埃及伊蚊体内的一种促性腺激素。使用 OEH I 抗血清进行的整体免疫细胞化学显示，这种蚊子的幼虫和成虫中免疫染色细胞的广泛分布与在非洲疟疾蚊子冈比亚按蚊中观察到的情况相当。对幼虫和成虫脑中的内侧神经分泌细胞进行染色。埃及伊蚊。在安.冈比亚的外侧神经分泌细胞染色更频繁。在这两个物种中，这些细胞的免疫染色轴突通过与主动脉相关的神经血管器官延伸出大脑，并沿着中肠广泛分支。在两个物种的幼虫和成虫中肠中观察到免疫染色的内分泌细胞。在成人中，腹部同色异质内脏周围器官被染色。染色的轴突将内脏周围器官和腹部神经节中的神经分泌细胞相互连接。在雌性白伊蚊中，这些器官中的 OEH I 间歇性释放是明显的。埃及伊蚊，染色在吸血后 12 小时消失，并在 48 小时恢复到吸血前和吸血后 2 小时观察到的水平。两个位点仅在 An 中被特异性染色。冈比亚：幼虫和成虫后肠幽门瓣周围的轴突网和幼虫中肠心脏瓣膜内的内分泌细胞环。两个远缘物种的幼虫和成虫中免疫染色细胞的定位明显相似，表明 OEH I 或同源物在这组双翅目中是保守的，并且可能具有阶段和性别特异性功能。
The activity of juvenile hormone esterase (JHE) in feeding fifth instar larvae of Manduca sexta increases gradually with larval weight when juvenile hormone secretion ceases. Starvation of larvae of Manduca sexta (L.) that had exceeded the critical weight inhibited peak levels of JHE, but did not delay entry into the wandering stage when larvae leave the plant in search of a pupation site. This suggests that peak levels of JHE may not be essential for the normal timing of metamorphosis. Starved larvae pupated normally, indicating the peak of JHE was not necessary for a morphologically normal pupation. Treatments of larvae with the selective JHE inhibitor O-ethyl-S-phenyl phosphoramidothiolate (EPPAT) that began immediately after larvae achieved the critical weight (6.0 to 6.5 grams for our strain of Manduca) delayed entry into the wandering stage. By contrast, EPPAT treatment of larvae at weights above 8.0g had no effect on the subsequent timing of the onset of wandering. Therefore, although the normal timing of the onset of wandering does not require peak levels of JHE, it requires low to moderate levels of JHE to be present until larvae reach a weight of about 8.0g.Ovary ecdysteroidogenic hormone I (OEH I) is a gonadotropin in the female mosquito, Aedes aegypti. Whole-mount immunocytochemistry using OEH I antisera revealed an extensive distribution of immunostained cells in larvae and adults of this mosquito comparable to that observed in the African malaria mosquito, Anopheles gambiae. Medial neurosecretory cells were stained in brains of larvae and adult Ae. aegypti. In An. gambiae the lateral neurosecretory cells were stained more often. In both species, immunostained axons from these cells extended out of the brain through the neurohemal organ associated with the aorta and branched extensively along the midgut. Immunostained endocrine cells were observed in larval and adult midguts of both species. In adults, abdominal metameric perivisceral organs were stained. Stained axons interconnected the perivisceral organs and neurosecretory cells in the abdominal ganglia. Episodic release of OEH I from these organs was evident in female Ae. aegypti, when staining disappeared at 12 hours after a blood meal and returned by 48 hours to levels observed before and up to 2 hours after the blood meal. Two sites were specifically stained only in An. gambiae: an axon net around the pyloric valve in the hindgut of larvae and adults and a ring of endocrine cells in the cardiac valve in the larval midgut. The markedly similar localizations of immunostained cells in larvae and adults of two distantly related species indicate that OEH I, or a homolog, is conserved within this group of Diptera and likely has stage- and sex-specific functions.