Juvenile hormone titers in the hemolymph during late larval development of the tobacco hornworm, Manduca sexta (L.).
Juvenile hormone titers in the hemolymph during late larval development of the tobacco hornworm, Manduca sexta (L.).
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烟草天蛾 Manduca sexta (L.) 幼虫发育晚期血淋巴中保幼激素滴度。
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发表时间：
1975
期刊：
影响因子：
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通讯作者：
L. Riddiford
中科院分区：
文献类型：
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作者：
M. J. Fain;L. Riddiford
保幼激素（JH）和昆虫中的许多其他发育激素一样，必须通过血淋巴到达其靶组织。因此，血淋巴浓度与JH的作用有着重要的关系（见de Wilde，de Kort and de Loof，1971），尽管组织中保留的激素或维生素D的浓度与JH的作用有关。激素的“隐蔽效应”也可能具有重要意义（例如，Ohtaki，Milk man，and威廉姆斯，1968 ; Nijhout，1975）.人们普遍认为JH滴度是100？在大多数的premetamorphic发展，但JH的影响是只在离散的时间在这个发展过程中显现-当蜕皮激素诱导蜕皮。烟草天蛾幼虫的结扎研究表明，在幼虫蜕皮中，JH对表皮定型的影响与蜕皮激素启动蜕皮过程同时发生（Truman，1972 ; Truman和Riddiford，1974）。这些研究和其他研究（Wigglesworth，1934 ; Fukuda，1944）的观察结果间接表明，在变态前蜕皮中，促前胸腺激素（PTTH）释放时，即蜕皮激素分泌的关键期之前，JH滴度可能非常低。其他报告表明，即使在幼虫蜕皮中，蜕皮激素和JH的大量滴度也不会同时发生（Patel和Madhavan，1969）。通过间接测量咽侧体（CA）的细胞学、大小或活性变化，已经推断出了许多关于JH滴度的信息（参见Doane，1973），但这些方法存在困难（威廉姆斯，1961;约翰逊和Hill，1973 a），需要直接测定血淋巴滴度。烟草角虫特别适合于在幼虫发育期间对JH的血淋巴滴度进行这样的调查。你是谁？通过光周期对PTTH释放进行“门控”（Tru nian，1972），可以选择发育同步的动物组，从中获取血淋巴进行分析。观察到的滴度可以与相对于PTTH和蜕皮激素释放的发育事件精确相关。最后，血淋巴样品中的JH含量可以在生物测定系统中使用提供血淋巴的健全物种和阶段的测定动物进行分析。本报告描述了通过利用黑色突变体幼虫进行灵敏且定量的JH生物测定来测定野生型天蛾幼虫第四和第五龄期间甲淋巴中的JH滴度（Safranek和Riddi福特，1975年）。
The juvenile hormone (JH) , as with many other developmental hormones in insects, must reach its target tissues by way of the hemolymph. Thus, the hemolymph concentration bears an important relation to effects of JH ( see de Wilde, de Kort and de Loof, 1971 ) , although tissue retention of hormone or of “?�covert effectsâ€of hormone may be of significance as well (e.g., Ohtaki, Milk man, and Williams, 1968 ; Nijhout, 1975). It is generally accepted that the JH titer is “?�high†during most of premetamorphic development, yet the effects of JH are made manifest only at discrete times during this development—when ecdysone induces a molt. Ligation studies of larvae of the tobacco hornworm Manduca sexta suggest that in a larval molt, the effects of JH on epidermal commitment occur simultaneously with initiation of the molting process by ecdysone (Truman, 1972 ; Truman and Riddiford, 1974) . Observations in these studies and in others (Wigglesworth, 1934 ; Fukuda, 1944) suggest indirectly that in premetamorphic molts the JH titer, in fact, may be very low at the time of prothoracicotropic hormone (PTTH) release, just prior to the critical period for ecdysone secretion. Other reports suggest that substantial titers of ecdysone and of JH do not occur simultaneously even in a larval molt (Patel and Madhavan, 1969). Much has been deduced about JH titers from indirect measurements of cyto logical, size, or activity changes in the corpora allata (CA) (see Doane, 1973), but there are difficulties with such methods (Williams, 1961; Johnson and Hill, 1973a) and direct determination of hemolymph titers is desirable. The tobacco horn worm is especially suited for such an investigation of hemolymph titers of JH during larval development. The “?�gating†of PTTH release by photoperiod (Tru nian, 1972) allows one to select developmentally synchronous groups of animals from which to obtain hemolymph for analysis. Titers observed can be correlated precisely with developmental events relative to the release of PTTH and ecdysone. Finally, the JH content of hemolymph samples can be analyzed in a bioassay system using assay animals of the sanie species and stage as those which provided the hemolymph. This report describes the determination of JH titers in heniolymph during the fourth and fifth instars of wild-type Manduca larvae, by means of a sensitive and quantitative JH bioassay utilizing larvae of the black mutant (Safranek and Riddi ford, 1975).