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1.
In vitro spermatogenesis takes place when intact testes are cultured in blood plasma containing ecdysone or certain other steroids possessing ecdysone activity. The ecdysone requirement can be satisfied by culturing the testes in the presence of living, active prothoracic glands. The most likely explanation of these results is that the prothoracic glands constitute the principal source of ecdysone. 相似文献
2.
Although functions for the steroid hormone ecdysone during Drosophila metamorphosis have been well established, roles for the embryonic ecdysone pulse remain poorly understood. We show that the EcR-USP ecdysone receptor is first activated in the extraembryonic amnioserosa, implicating this tissue as a source of active ecdysteroids in the early embryo. Ecdysone signaling is required for germ band retraction and head involution, morphogenetic movements that shape the first instar larva. This mechanism for coordinating morphogenesis during Drosophila embryonic development parallels the role of ecdysone during metamorphosis. It also provides an intriguing parallel with the role of mammalian extraembryonic tissues as a critical source of steroid hormones during embryonic development. 相似文献
3.
K D Wing 《Science (New York, N.Y.)》1988,241(4864):467-469
The steroid molting hormone 20-hydroxyecdysone is the physiological inducer of molting and metamorphosis in insects. In ecdysone-sensitive Drosophila Kc cells, the insecticide RH 5849 (1,2-dibenzoyl-1-tert-butylhydrazine) mimics the action of 20-hydroxyecdysone by causing the formation of processes, an inhibition of cell proliferation, and induction of acetylcholinesterase. RH 5849 also competes with [3H]ponasterone A for high-affinity ecdysone receptor sites from Kc cell extracts. Resistant cell populations selected by growth in the continued presence of either RH 5849 or 20-hydroxyecdysone are insensitive to both compounds and exhibit a decreased titer of measurable ecdysone receptors. Although it is less potent than 20-hydroxyecdysone in both whole-cell and cell-free receptor assays, RH 5849 is the first nonsteroidal ecdysone agonist. 相似文献
4.
Larvae of the fly Calliphora erythrocephala (Meigen) were deprived surgically of their ring glands at an age prior to the appearance of ecdysone in the blood, and then injected with ecdysone. They contracted into the typical barrel-shaped puparium, before the onset of tanning. This proved that ecdysone controls the puparium contraction as well as tanning. 相似文献
5.
Beach R 《Science (New York, N.Y.)》1979,205(4408):829-831
Biting in Anopheles freeborni is inhibited during ovarian development. Biting inhibition is triggered by ecdysone, a hormone produced by the ovary during oogenesis. Biting inhibition does not occur in females after the removal of ovaries, but is restored by replacing ovaries or injecting ecdysone. Ecdysone also inhibits biting behavior when it is fed to females. This is the first example of ecdysone controlling a nonmolt-related behavior in insects. 相似文献
6.
The ecdysone agonist RH 5849 (1,2-dibenzoyl-1-tert-butylhydrazine) causes the premature initiation of molting at all stages of larval development of the tobacco hornworm, Manduca sexta. This phenomenon occurs without an increase in the endogenous ecdysone (20-hydroxyecdysone) titers. RH 5849 likewise provokes the initiation of molting in larval abdomens in the absence of a source of endogenous hormone. Although substantially less active than 20-hydroxyecdysone in vitro, RH 5849 was 30 to >670 times as active as the authentic molting hormone in bioassays with isolated larval abdomens or intact hornworms. This reversal in potency can be attributed to the superior transport properties and metabolic stability of RH 5849 relative to 20-hydroxyecdysone. Thus RH 5849 and its analogs are relatively persistent ecdysone agonists that halt feeding in larval lepidoptera by forcing an ultimately lethal, developmentally premature molt. 相似文献
7.
Robbins WE Kaplanis JN Thompson MJ Shortino TJ Cohen CF Joyner SC 《Science (New York, N.Y.)》1968,161(3846):1158-1160
Ingestion of certain synthetic ecdysone analogs inhibited larval growth and development in several species of insects, whereas 20-hydroxyecdysone was inactive or considerably less active. Natural 20-hydroxyecdysone and ponasterone A, and a synthetic ecdysone analog inhibited ovarian maturation and egg production in the adult housefly. These effects appeared to be related to hormonal activity. 相似文献
8.
The two major molting hormones of insects, alpha ecdysone and 20-hydroxyecdysone, were isolated in crystalline form from dry pinnae of the bracken fern, Pteridium aquilinum (L.) Kuhn. Three unidentified substances with molting hormone activity were also detected. Bracken is the first plant found to contain both of the major insect ecdysones, and it is the first known plant source of alpha ecdysone. 相似文献
9.
Newly laid eggs of the insect Locusta migratoria contain high concentrations (50 nanomoles per gram) of an ecdysone conjugate of maternal origin; 3 milligrams of this conjugate were isolated by conventional techniques, and the structure was established by mass spectrometry and (1)H, (13)C, and (31)P nuclear magnetic resonance as the 22-N(6)-(isopentenyl)-adenosine monophosphoric ester of ecdysone. 相似文献
10.
Bracken contains ecdysone derivatives that are active when injected into locusts. However, when fed to the desert locust as its sole or chief diet, it does not affect molting, growth, or development. There is evidence that, in locusts, the active ecdysones are dehydroxylated to (alpha)-ecdysone and passed out through the gut in the feces. There is no evidence for any uptake of ecdysones from the gut. 相似文献
11.
Biosynthesis of agr and beta-Ecdysones from Cholesterol outside the Prothoracic Gland in Bombyx mori
Labeling experiments have established that cholesterol is converted into alpha-and beta-ecdysones in isolated abdomens of silkworm larvae. Since the isolated abdomens do not contain the prothoracic glands, a doubt is cast on the long-standing principle in insect endocrinology that the prothoracic glands are the source of ecdysone secretion. 相似文献
12.
Five fractions of the growth and differentiation hormone, ecdysone, separated from extracts of Bombyx have been detected by bioassay. Three of these have not been described heretofore. 相似文献
13.
蜕皮贯穿甲壳动物生长发育的始终。概述了调控甲壳动物蜕皮的主要内分泌腺(Y-器官、大颚器官、X-器官窦腺复合体等)以及外源性激素(高等动物性激素、脊椎动物生长激素、外源性蜕皮激素和外源性保幼激素拮抗物),其中保幼激素拮抗物作为甲壳动物促生长剂,高效、低成本、相对安全。 相似文献
14.
【目的】蜕皮激素（ecdysone）是昆虫体内一种重要的激素,参与调控昆虫的生长发育,并且能对环境胁迫进行响应。研究旨在明确橘小实蝇（Bactrocera dorsalis Hendel）蜕皮激素合成通路基因（ecdysone synthesis pathway gene）的分布和特定条件下的表达特性,为进一步开展橘小实蝇变态发育与抗逆胁迫机制的研究提供理论支持。【方法】采用RT-PCR和RACE技术克隆蜕皮激素合成通路基因BdCyp302a1、BdCyp315a1和BdCyp314a1,利用实时定量PCR（qPCR）技术检测该合成通路基因BdNvd、BdCyp306a1、BdCyp302a1、BdCyp315a1和BdCyp314a1在幼虫不同发育阶段（幼虫1-8日龄）、不同组织（前胸腺复合体、脂肪体、中肠、马氏管、表皮和气管）和饥饿条件下的表达模式,明确饥饿对幼虫发育的影响。【结果】克隆获得了3个蜕皮激素合成通路基因序列的开放阅读框,分别为BdCyp302a1（GenBank登录号：JQ027284）、BdCyp315a1（GenBank登录号：KC515377）和BdCyp314a1（GenBank登录号：JQ229645）,且上述序列均具备P450典型结构域：Helix-C/I/K、PERF基序、血红蛋白结合位点以及脯氨酸/甘氨酸富集区,其氨基酸序列较为保守。qPCR检测结果显示蜕皮激素合成通路基因BdNvd、BdCyp306a1和BdCyp314a1幼虫末龄阶段表达量显著升高,其最高表达量分别是最低点的7.33、10.89和7.82倍,但在幼虫前4 d表达量差异不显著。而BdCyp302a1和BdCyp315a1在整个幼虫阶段表达量保持相对稳定。对不同组织的研究发现,蜕皮激素合成通路基因在所选的6个组织中均有表达,其中BdNvd、BdCyp306a1和BdCyp315a1在幼虫前胸腺表达量最高,在其他组织中表达量差异不显著;BdCyp302a1在各组织中的表达量由高到低为脂肪体>前胸腺>表皮/马氏管>气管/中肠,该基因在脂肪体的表达量是中肠的30倍;BdCyp314a1在中肠、马氏管和脂肪体内的表达量依次降低,但均极显著高于其他3个组织。橘小实蝇幼虫在饥饿处理12 h后即出现化蛹现象,其化蛹比例随饥饿时间延长而上升。对蛹宽和蛹长的测量中发现,饥饿导致蛹个体显著缩小,但未影响其存活率。同时,饥饿导致蜕皮激素合成通路基因BdNvd、BdCyp302a1和BdCyp314a1表达量在饥饿处理6 h后出现显著上调,并在处理48 h后出现显著下调;但饥饿处理并未影响BdCyp315a1的表达水平。【结论】蜕皮激素合成通路基因在橘小实蝇幼虫组织的表达具有差异性,并参与介导幼虫-蛹的变态过程和对营养胁迫的响应。 相似文献
15.
【目的】昆虫变态发育的启动主要受前胸腺合成分泌的蜕皮激素所调控,而蜕皮激素的合成是由细胞色素P450基因催化完成。家蚕（Bombyx mori）是一种产丝昆虫,蚕业生产中如果能阻断或延迟家蚕蛹变态发育进程,将有利于改进蚕茧处理工艺,提高蚕丝品质。论文旨在鉴定参与家蚕蜕皮激素合成的细胞色素P450基因,从而为人为遗传调节家蚕变态发育提供靶基因。【方法】基于序列同源性比对,筛选家蚕及其他昆虫中参与蜕皮激素合成的P450基因。利用ClustalW软件,分析昆虫蜕皮激素合成相关P450基因的遗传发生关系。通过全基因组表达芯片数据分析及RT-PCR验证,调查家蚕蜕皮激素合成相关P450基因的时空表达特征。利用RNAi技术分析Cyp314a1表达下调对家蚕变态发育的影响。【结果】家蚕基因组中有4个参与家蚕蜕皮激素合成的P450基因,即Cyp306a1、Cyp302a1、Cyp315a1和Cyp314a1。比较分析显示,这4个蜕皮激素合成相关的P450基因在家蚕及其他昆虫中都是单拷贝,而且每个基因的同源体在遗传发生树上能很好地聚成一类,表明昆虫蜕皮激素合成相关的P450基因及其负责的蜕皮激素合成通路非常保守。时空表达谱分析显示,在家蚕幼虫5龄第3天,Cyp302a1、Cyp315a1和Cyp314a1主要在家蚕幼虫卵巢、精巢和头部等组织器官中高表达;在幼虫-蛹-成虫变态发育进程中,Cyp302a1、Cyp315a1和Cyp314a1主要在蛹变态发育后期表达,其中Cyp314a1分别在上簇、化蛹及羽化前高表达,这与蜕皮激素滴度高峰出现的时期基本一致。Cyp314a1的RNAi导致家蚕不能正常化蛹及雌蛾卵巢发育异常,且降低了蜕皮激素信号通路关键基因HR3及Ftz-f1的表达。【结论】家蚕蜕皮激素合成相关的P450基因在进化上非常保守,其表达水平降低能引起家蚕蛹变态发育受阻,暗示蜕皮激素合成相关P450基因可以用作家蚕变态发育控制的靶标基因之一。 相似文献
16.
中华绒螯蟹在“蟹龙宫”饲养环境中的个体蜕壳与生长 总被引：1，自引：1，他引：0
分析"蟹龙宫"饲养中华绒螯蟹(Eriocheir sinensis)在一个蜕壳周期的蜕壳与生长情况。结果发现:"蟹龙宫"饲养中华绒螯蟹蜕壳后体质量平均增长率为33.19%,头胸甲长、头胸甲宽和体高的平均增长率为12.12%～14.97%,平均蜕壳间期为59.35 d。蜕壳前平均肥满度达60.84%,头胸甲的色度值(RGB)平均为109.17,蜕皮激素(EH)含量达14.18 IU/mL。试验河蟹在蜕壳前生长性状、EH含量和蜕壳间期长短与蜕壳后的增长率不存在显著相关性(P0.05)。在"蟹龙宫"的个体养殖系统中,中华绒螯蟹的肥满度达60%,蜕皮激素含量升至14 IU/mL时会启动蜕壳。 相似文献
17.
Chino H Sakurai S Ohtaki T Ikekawa N Miyazaki H Ishibashi M Abuki H 《Science (New York, N.Y.)》1974,183(4124):529-530
An in vitro study in which isolated prothoracic glands of the Bombyx silkworm were cultured has provided definite evidence that the prothoracic gland is the site where molting hormone is synthesized. The hormone behaved very similarly to free ecdysone on thin-layer chromatography. Analysis by liquid chromatography and mass fragmentography revealed that the hormone is identical with alpha-ecdysone. 相似文献
18.
19.
野桑蚕不同组织细胞色素P450 CYP305B1V1基因的诱导表达特征研究 总被引：3，自引：0，他引：3
[目的]研究不同诱导物对野桑蚕各组织中细胞色素P450CYP30581V1基因表达的影响。[方法]参照GenBank中公布的野桑蚕CYP305B1V1基因的mRNA序列,设计1对引物,采用半定量RT-PCR方法分析经NaF、芸香苷、氯氰菊酯和蜕皮激素处理的野桑蚕各组织中CYP305B1V1基因的表达情况,并对该基因的氨基酸序列进行同源性比较和进化分析。[结果]氯氰菊酯、芸香苷和NaF影响野桑蚕6TP305B1V1基因在组织中的表达,蜕皮激素无明显影响。氨基酸的同源性分析表明该基因氨基酸序列与家蚕CYP305B1的氨基酸序列同源性最高（100％）;与赤拟谷盗推测的CYP305A1、蜜蜂推测的CYP305A1、果蝇CYP305A1、冈比亚按蚊CYP305A2及库蚊CYP2L1有较高的同源性。[结论]野桑蚕CYP30581V1基因可能主要参与外源性化舍物的代谢,对揭示细胞色素P450的功能和不同药物的代谢机理具有重要意义。 相似文献
20.
定虫脲(CFU)系苯酰基苯脲类系列药剂中有较高药效的一个品种,它对三龄粘虫幼虫的毒效作用较其第一代杀虫剂除出脲(Diflubenzuron)高约70倍,对六龄粘虫幼虫,用点滴、胃毒和注射方法处理,最终毒效相若。根据粘虫六龄幼虫表皮几丁质含量的动态变化,在不同时龄时用点滴法施药,发现试虫的死亡时间和受药时间有明显相关。以72时龄为界,在此以前受药者试虫多数不能变态,死亡于化蛹之前。而72时龄以后施药者,试虫则多数可变态,但在蛹期陆续死亡。因此,72时龄是表皮几丁质沉积的分界线,但并未发现施药后的原位反应(insi-tu)或几丁质厚度和药效之问的相关。 相似文献