Juvenile hormone induction of biting behavior in culex mosquitoes

Juvenile hormone deprivation caused by surgical removal of corpora allata shortly after adult emergence blocked the initiation of biting behavior in Culex. pipiens and Culex quinquefasciatus. Reimplantation of corpora allata or injection of a synthetic juvenile hormone (JH-I) corrected the juvenile hormone deficiency and restored biting behavior. Ovariectomy experiments demonstrated that this behavioral effect of juvenile hormone was independent of ovarian involvement.     

化学放射法测定蜜蜂保幼激素酯酶活性

蜜蜂保幼激素(JH)是由蜜蜂咽侧体(CA)合成和分泌的一种氧化物。保幼激素酯酶是对蜜蜂体内呈游离态或结合态的保幼激素进行专化性降解的特异性酯酶。采用放射化学法(RC)测定了西方蜜蜂(Apis mellifera L．)不同日龄工蜂体内保幼激素酯酶(JHE)的活性。结果表明，工蜂体内保幼激素酯酶活性随着日龄的增大而下降。     

Prevention of metamorphosis by exposure of insect eggs to juvenile hormone analogs

Metamorphosis of the bugs Pyrrhocoris apterus and Oncopeltus fasciatus is blocked by the application of juvenile hormone analogs to the eqgs 4 weeks earlier. One or more supernumerary larval molts occur to form "giant" larvae which routinely die without undergoing netamorphosis. When the corpora allatta were excised at the outset of the fifth larval stage, the entire phenomenon vanished and all individuals underwent normal metamorphosis. The inhibition of metamorphosis can therefoore be attributed to a continuation of the secretion of endogenous juvenile hormone by the corpora allata of mature larvae deried from eggs treated with juvenile hormone.     

Involvement of juvenile hormone in the regulation of pheromone release activities in a moth

Juvenile hormone has been implicated in the mediation of several reproduction-related events in adult insects, but had previously been found to play no role in the regulation of sex pheromone production and release behavior ("calling") in moths. In females of the true armyworm moth, Pseudaletia unipuncta, juvenile hormone is shown to be essential to the initiation of both calling behavior and pheromone production. Females without corpora allata, the source of juvenile hormone, do not call and do not produce pheromone, but injection of juvenile hormone into allatectomized females restored these activities. The armyworm's control system has likely evolved in response to the adults' migratory behavior which may necessitate that mating be restricted to the period following migration.     

Identification of an allatotropin from adult manduca sexta

A peptide that strongly stimulates the secretion of juvenile hormone from corpora allata in vitro (allatotropin) has been purified from extracts of heads of pharate adult Manduca sexta. The primary structure of this 13-residue peptide has been determined: H-Gly-Phe-Lys-Asn-Val-Glu-Met-Met-Thr-Ala-Arg-Gly-Phe-NH(2). This neurohormone has no sequence similarity with any known neuropeptide from other organisms. Synthetic allatotropin, as well as truncation fragments, including one with the five amino terminal residues deleted, showed in vitro activity indistinguishable from that of native allatotropin.     

Luteinizing hormone: action on the graafian follicle in vitro

Graafian follicles, dissected intact from the rabbit ovary and incubated for 40 minutes with luteinizing hormone, developed into corpora lutea when autotransplanted under the kidney capsule. Follicles incubated with follicle-stimulating hormone or without hormone degenerated and failed to luteinize. Direct exposure of the mammalian follicle to luteinizing hormone initiates luteinization and formation of the corpus luteum.     

THE ISOLATION IN PURE FORM OF THE INTERSTITIAL CELL-STIMULATING (LUTEINIZING) HORMONE OF THE ANTERIOR LOBE OF THE PITUITARY GLAND

Interstitial cell-stimulating (luteinizing) hormone was isolated from swine pituitary glands. This protein hormone, having a molecular weight of about 90,000 and an isoelectric point of pH 7.45, was shown to be pure by tests in the electrophoresis apparatus of Tiselius and in the ultracentrifuge as well as by its constant solubility. The hormone stimulated the interstitial tissue of the testis or ovary and caused the formation of corpora lutea provided that maturing follicles were present. Under the conditions described, its minimal effective total dose in hypophysectomized immature male rats was about 1 microgram of nitrogen or 6.7 micrograms of hormone. Extracts of swine pituitary with purely follicle-stimulating effects did not cause oestrus in immature hypophysectomized female rats unless luteinizing hormone was also administered.     

Control of Oocyte Development in Cockroaches

Development of ovarian eggs and secretory activity of colleterial glands are inhibited by the o?theca in the o?thecal chamber of Blattella germanica (L.) and by the o?theca in the uterus of Pycnoscelus surinamensis (L.). The inhibition is due to nervous stimuli from pressure of the o?theca. Removing the o?theca or severing the ventral nerve cord eliminates inhibition of the corpora allata and results in premature development of the o?cytes and resumption of activity of the colleterial glands.     

灭幼脲毒理学研究——Ⅳ.灭幼脲的激素效应模拟试验

以灭幼脲(Diflubenzuron,DFB)极高剂量(死亡剂量)处理6龄粘虫幼虫,对少数存活且外观健壮的试虫作组织学观察,发现对激素分泌器官咽侧体(CA)及前胸腺(PG)以及激素作用靶器官脂肪体(FB)都表现刺激效应。保幼激素(JH)类似物ZR-515,蜕皮激素(MH)和DFB单用或混用,以脂肪体合成蛋白质能力的高低作为比较指标,发现DFB和ZR-515有类似效应;MH则可促进蛋白质合成或吸收能力,但和DFB合用后,其能力下降。由此表明,DFB可能系通过类似JH效应,从而增加体内JH影响,引起内源性激素平衡失调作为其毒杀机制的重要方面。     

Juvenile hormone action mediated in male accessory glands of Drosophila by calcium and kinase C

In an in vitro system for the Drosophila melanogaster male accessory gland, it was found that 10(-9)M juvenile hormone III could accurately mimic the copulation-induced response of increased protein synthesis in glands from virgin flies. Stimulation by this hormone required calcium in the medium. Experiments with tumor-promoting phorbol esters indicated that activation of protein kinase C can also cause the glands to increase protein synthesis. Stimulation of protein synthesis by juvenile hormone did not occur in mutants deficient in kinase C activity. These results suggest a membrane-protein-mediated effect of juvenile hormone that involves calcium and kinase C.     

Induction of ovulation in immature hypophysectomized rats

Immature rats given minute doses of highly purified pituitary gonadotropins (follicle-stimulating hormone and luteinizing hormone) 7 to 100 days after hypophysectomy ovulated and formed corpora lutea. Neither hormone alone was effective. Luteinizing hormone repaired in part the atrophied theca interna and interstitial tissue, and follicle-stimulating hormone stimulated the development of the granulosa cells.     

Juvenile hormone mimics: effect on cirriped crustacean metamorphosis

A synthetic juvenile hormone mimic has been shown to cause premature metamorphosis of the cyprid larva of an acorn barnacle in concentrations as low as 10 parts per billion in filtered seawater. The effect of a juvenile hormone mimic on a crustacean has not previously been demonstrated.     

昆虫保幼激素及其类似物的应用研究进展

介绍了昆虫保幼激素及其类似物应用于杀虫剂和昆虫生长调节剂的研究情况,并展望了昆虫保幼激素及其类似物的应用前景。     

板栗子房内源激素含量与空苞形成关系的研究

采艇控制授粉方法分析了板栗授粉前后子房内源激素含量的变化。结果表明,授粉刺激了板栗子房内源ＧＡ１／３、ｉＰＡ８含量及（ＧＡ１／３＋ｉＰＡｓ）／ＡＢＡ值增加,并降低了子房内源ＡＢＡ含量。未授粉子房和正常授粉子房在授粉前后内源激素含量及变化趋势上的差异,与空苞栗子房和正常栗子房间同一时期的差异基本相似,且未授粉子房内激激素含量变化与空苞栗一致,因此可认为板栗子房授粉不良是空苞形成的重要原因。     

Thymus and reproduction: sex-linked dysgenesia of the gonad after neonatal thymectomy in mice

Neonatal thymectomy of mice, when no ectopic thymus existed, constantly resulted in developmental arrest of the ovary but not of the testis; it also caused sterility in the female. The ovaries of thymectomized mice were extremely small and were characterized by absence of follicles and corpora lutea. Such an ovarian dysgenesia was observed when the mice were thymectomized at 3 days of age, but not at 7 days or later; it was prevented by thymus grafting.     

JH Zero: New Naturally Occurring Insect Juvenile Hormone from Developing Embryos of the Tobacco Hornworm

A new insect juvenile hormone was isolated from developing embryos of the tobacco hornworm moth, Manduca sexta. The new hormone was found with juvenile hormone I and is a 1-carbon homolog of this substance. The assigned structure is methyl (2E,6E,10-cis)-10,11-epoxy-3,7-diethyl-11-methyl-2,6-tridecadienoate, which constitutes a trishomosesquiterpenoid skeleton. This is the first chemical idetification of any juvenile hormone from insect eggs.     

A novel target for antidiuretic hormone in insects

Diuresis in insects is controlled by two antagonistic hormone groups: diuretic hormones, which promote water loss, and antidiuretic hormones, which inhibit it. All known antidiuretic factors act solely to promote fluid reabsorption by the hindgut and do not affect secretion by the Malpighian tubules. In the house cricket, Acheta domesticus, an antidiuretic hormone was found that inhibits fluid secretion by the Malpighian tubules but has no effect on the hindgut. Correlations were found between the density of neurosecretory granules and the presence of antidiuretic hormone in the corpora cardiaca, suggesting that the hormone is released from specific axons. Its release is triggered by dehydration; the hormone is detectable in the hemolymph of water-deprived crickets. These results imply that an unusual mechanism regulates water balance in these insects.     

Juvenile hormone is required to couple imaginal disc formation with nutrition in insects

In starved larvae of the tobacco hornworm moth Manduca sexta, larval and imaginal tissues stop growing, the former because they lack nutrient-dependent signals but the latter because of suppression by juvenile hormone. Without juvenile hormone, imaginal discs form and grow despite severe starvation. This hormone inhibits the intrinsic signaling needed for disc morphogenesis and does so independently of ecdysteroid action. Starvation and juvenile hormone treatments allowed the separation of intrinsic and nutrient-dependent aspects of disc growth and showed that both aspects must occur during the early phases of disc morphogenesis to ensure normal growth leading to typical-sized adults.     

Soldier determination in ants: new role for juvenile hormone

Topical application of juvenile hormone analog induces soldier development in the ant Pheidole bicarinata. Soldier induction takes place if the juvenile hormone analog is present during a period of sensitivity that occurs during the last larval instar. Control of worker dimorphism seems to be accomplished through control of timing of metamorphosis. The smallest size at which metamorphosis can be initiated is shifted upwardfrom 1.2 to 1.7 millimeters by exposure to the juvenile hormone analog during the sensitive period.     

灭幼脲毒理学研究——Ⅶ.灭幼脲对东方粘虫末龄幼虫保幼激素滴度的影响

以蜡螟生测法测定了72时龄以内的东方粘虫(Mythimna separata Walkcr)末龄幼虫的保幼激素动态及灭幼脲对其影响,发现在48时龄。保幼激素滴度下降到极低水平时,灭幼脲可使保幼激素滴度堆持在一个高于正常幼虫的水平。不同时龄滴加保幼激素类似物ZR-512,发现幼虫可因施药期不同而对ZR-512产生不同效应,其转换期也是在幼虫发育到48时龄的时候,由此讨论了由于灭幼脲对保幼激素滴度在转换期间不下降到规定阈值,可能干扰了激素序列的调控,导致蜕皮、变态异常的毒理学机制。