Extension of life-span by loss of CHICO, a Drosophila insulin receptor substrate protein

The Drosophila melanogaster gene chico encodes an insulin receptor substrate that functions in an insulin/insulin-like growth factor (IGF) signaling pathway. In the nematode Caenorhabditis elegans, insulin/IGF signaling regulates adult longevity. We found that mutation of chico extends fruit fly median life-span by up to 48% in homozygotes and 36% in heterozygotes. Extension of life-span was not a result of impaired oogenesis in chico females, nor was it consistently correlated with increased stress resistance. The dwarf phenotype of chico homozygotes was also unnecessary for extension of life-span. The role of insulin/IGF signaling in regulating animal aging is therefore evolutionarily conserved.     

Antiallatotropins: inhibition of corpus allatum development

Treatment of newly eclosed adult milkweed bug (Oncopeltus fasciatus) females with precocene 2 prevents secretion of juvenile hormone by inhibition of postimaginal development of the corpus allatum. Ovarian development which is dependent upon juvenile hormone is prevented or reversed, depending upon the timing of precocene treatment. Juvenile hormone secretion is shown to be related to the development of the corpus allatum.     

Feedback control of juvenile hormone synthesis in cockroaches: possible role for ecdysterone

Inactive female corpora allata implanted into adult males become active and continue to synthesize juvenile hormone at high rates. However, when an ovary is implanted together with the corpora allata, rates of juvenile hormone synthesis decline as the oocytes complete maturation. Injections of ecdysterone mimic the effect of an implanted ovary.     

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.     

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.     

The endocrine regulation of aging by insulin-like signals

Reduced signaling of insulin-like peptides increases the life-span of nematodes, flies, and rodents. In the nematode and the fly, secondary hormones downstream of insulin-like signaling appear to regulate aging. In mammals, the order in which the hormones act is unresolved because insulin, insulin-like growth factor-1, growth hormone, and thyroid hormones are interdependent. In all species examined to date, endocrine manipulations can slow aging without concurrent costs in reproduction, but with inevitable increases in stress resistance. Despite the similarities among mammals and invertebrates in insulin-like peptides and their signal cascade, more research is needed to determine whether these signals control aging in the same way in all the species by the same mechanism.     

植物矮化基因相关研究进展

植物株型的矮化调控是遗传育种的一项热门研究。国内外学者对植物矮化机理、矮化基因、矮化遗传育种等均进行了较深入的研究,水稻、玉米、小麦等粮食作物和黄瓜、番茄、南瓜等园艺作物均已形成了较完善的矮化研究体系。矮化植株株型紧凑、冠幅小,能够有效提高抗倒伏能力,在生产实践中具有管理便利的优点,因此矮化育种是植物育种的发展趋势。激素调控是目前运用较为广泛的矮化调控手段,植物激素通过影响细胞的分裂和伸长来改变节间长度和数目,从而调节高度,达到矮化植株的效果,常用激素有赤霉素、油菜素内酯、生长素、乙烯等,这些激素促进或抑制植物的生长发育,与矮化突变体的形成有关,且各种激素信号通路之间存在相互作用。综述了禾本科、茄科、葫芦科等植物矮化基因的研究现状,激素调控下矮化突变体的形成,矮化基因的克隆及功能研究进展,探讨了植物矮生性状分子机理和分子遗传学研究进展,为后续研究植物矮化基因提供理论基础。     

温度和营养条件对管侧沟茧蜂成虫寿命的影响

在室内控温条件下,研究了不同温度和营养条件对管侧沟茧蜂成虫寿命的影响。结果表明：成虫寿命随温度的升高而缩短,不同温度条件下成虫寿命存在显著差异;补充水分对管侧沟茧蜂成虫寿命没有明显影响,补充蜂蜜水能明显延长成虫寿命。在18℃饲喂20%蜂蜜水条件下,成虫寿命最长（雌虫为24.6±3.0d,雄虫为13.8±2.5d）,且相同条件下雌成虫寿命长于雄成虫;在30℃不饲喂条件下,成虫寿命最短（雌成虫为1.4±0.1 d,雄成虫为1.2±0.1 d）。     

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。     

Lethal effects of synthetic juvenile hormone on larvae of the yellow fever mosquito, Aedes aegypti

Emergence of adult mosquitoes is blocked after the addition of 1 part of crude synthetic juvenile hormone to 100,000 parts water. Development is arrested at stages ranging from pupae to fully formed pharate adults incapable of escaping from the pupal exuvium. Fourth-stage larvae just prior to metamorphosis are most sensitive: 40 percent were killed after being exposed for 1 dayto 1 part juvenile hormone in 2 million parts water. The active material also inhibits the hatching of mosquito eggs.     

Plant Biology. Hormones and the green revolution

The success of the green revolution largely resulted from the creation of dwarf cultivars of wheat and rice, which had much higher yields than conventional crops. Characterization of these dwarf cultivars showed that the mutant genes were involved in either the synthesis or signaling of gibberellin, a plant growth hormone. In his Perspective, Salamini highlights new work (Multani et al.) that identifies the cause of dwarfism in agronomically important varieties of maize and sorghum. In these cases, dwarfism is caused by defective transport of another growth hormone called auxin.     

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.     

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.     

Timing requirements for insulin/IGF-1 signaling in C. elegans

The insulin/IGF-1 (where IGF-1 is insulin-like growth factor-1) signaling pathway influences longevity, reproduction, and diapause in many organisms. Because of the fundamental importance of this system in animal physiology, we asked when during the animal's life it is required to regulate these different processes. We find that in Caenorhabditis elegans, the pathway acts during adulthood, to relatively advanced ages, to influence aging. In contrast, it regulates diapause during development. In addition, the pathway controls longevity and reproduction independently of one another. Together our findings show that life-span regulation can be dissociated temporally from phenotypes that might seem to decrease the quality of life.     

陆地棉半矮秆突变体sd株高对外源激素的敏感性

【目的】研究外源激素对棉花矮化突变体株高的影响,确定其对激素的敏感性,为利用其分析棉花株高遗传基础与激素调控关系提供依据。【方法】以棉花品种新陆早17号(CK)及其矮化突变体sd为材料,采用GA₃、IAA和BR激素分别处理后,研究不同激素和不同浓度处理对棉花株高的影响。【结果】突变体sd的株高约为新陆早17号的四分之三,突变体sd是一份典型的陆地棉半矮秆突变体。不同浓度GA₃处理后,新陆早17号的株高变化量高于突变体,50 mg/L的GA₃处理能使突变体sd的株高恢复到新陆早17号的株高水平,激素影响棉花株高的主次顺序为GA₃＞BR＞IAA,株高与GA₃具有显著的正相关性。【结论】突变体sd是一份典型的陆地棉半矮秆突变体,突变体sd的株高对GA₃敏感。     

Amino-terminal amino Acid sequence of the silkworm prothoracicotropic hormone: homology with insulin

Three molecular forms of prothoracicotropic hormone were isolated from the head of the adult silkworm, Bombyx mori, and the amino acid sequence of 19 amino acid residues in the amino terminus of these prothoracicotropic hormones was determined. These residues exhibit significant homology with insulin and insulin-like growth factors.     

2种矮化砧P22和SH3对富士苹果实生后代童期的影响

利用当年生富士苹果实生苗高位芽,嫁接到中间矮化砧木P22和SH3上,调查苹果实生苗度过童期的时间、始花部位和开花株数等,研究了2种矮化中间砧对富士实生苗童期的影响。结果表明：2种矮化砧均能明显缩短富士苹果实生苗的童期。用生长2 a的富士苹果实生苗嫁接在2种矮化砧木上,至少能够缩短童期2 a以上。但P22和SH3这2种矮化砧木缩短实生苗童期的效果存在较大差异,利用P22较利用SH3开花节数更少、开花高度更低、童期更短。利用2种矮化砧木的实生苗,开花平均高度均〉200 cm,平均节位数〉100节,且首次开花部位在侧枝顶花芽的占全部开花株数的50%以上。     

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。     

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.