共查询到20条相似文献,搜索用时 31 毫秒
1.
Que Lan Anna Gerenday Ann Marie Fallon 《In vitro cellular & developmental biology. Animal》1993,29(10):813-818
Summary To provide a framework for biochemical investigation of ecdysteroid action inAedes albopictus mosquito cells, we examined the effect of 20-hydroxyecdysone on cell growth and morphology, synthesis of inducible proteins
(EIPs), and expression of a transfected gene regulated by a synthetic ecdysteroid response element. When cells were cultured
in the continuous presence of 10−6
M 20- hydroxyecdysone, the rate of growth decreased and subtle changes in cell morphology were observed. In bothAedes aegypti andA. albopictus cells, synthesis of a small number of radiolabeled proteins, which appeared as minor bands on sodium dodecyl sulfate-polyacrylamide
gels, was induced by treatment with 20-hydroxyecdysone. On two-dimensional polyacrylamide gels, 11 EIPs, ranging in size from
approximately 22 to 52 kDa, were identified inA. albopictus C7-10 cells. Ten inducible proteins were localized in the cytoplasmic fraction; EIP28 and EIP31 were detected in both cytoplasmic
and nuclear extracts, and EIP29 was detected only in the nucleus, at a very low level. None of these proteins corresponded
to small heat shock proteins, whose genes are 20-hydroxyecdysone-inducible in someDrosophila cell lines. The juvenile hormone analog, methoprene, induced expression of a 25 kDa protein in C7-10 cells. Although 20-hydroxyecdysone
sustained the synthesis of this methoprene-inducible protein, synthesis did not occur in the presence of 20-hydroxyecdysone
alone. In transfectedA. albopictus cells, expression of a recombinant DNA construct containing two tandem synthetic ecdysteroid regulatory elements based on
aD. melanogaster small heat shock protein gene was modestly induced by 20-hydroxyecdysone. 相似文献
2.
3.
The control of Malpighian tubule developmental physiology by 20-hydroxyecdysone and juvenile hormone
J.S. Ryerse 《Journal of insect physiology》1980,26(7):449-457
The control of developmental changes in Malpighian tubule cell structure and fluid secretion by 20-hydroxyecdysone and juvenile hormone in the skipper butterfly Calpodes ethlius were studied using (1) in vitro tissue culture, (2) in vivo injection and topical application and (3) tubule transplantation experiments. At pupation, 20-hydroxyecdysone initiates cell remodelling and switches off fluid secretion in the Malpighian tubules. Juvenile hormone inhibits these alterations provided that treatment is begun on the first day of the last larval stage. In the pupal stage, 20-hydroxyecdysone triggers the differentiation of adult cell structure which culminates in the renewal of fluid secretion. The results show that 20-hydroxyecdysone and juvenile hormone regulate Malpighian tubule function by altering cell structure and are discussed with respect to the hormonal reprogramming of the Malpighian tubule cells during development. 相似文献
4.
Xinmiao Fu Xiaodong Shi Linxuan Yan Hanlin Zhang Zengyi Chang 《The Journal of biological chemistry》2013,288(44):31646-31654
Small heat shock proteins (sHSPs), as ubiquitous molecular chaperones found in all forms of life, are known to be able to protect cells against stresses and suppress the aggregation of a variety of model substrate proteins under in vitro conditions. Nevertheless, it is poorly understood what natural substrate proteins are protected by sHSPs in living cells. Here, by using a genetically incorporated photo-cross-linker (p-benzoyl-l-phenylalanine), we identified a total of 95 and 54 natural substrate proteins of IbpB (an sHSP from Escherichia coli) in living cells with and without heat shock, respectively. Functional profiling of these proteins (110 in total) suggests that IbpB, although binding to a wide range of cellular proteins, has a remarkable substrate preference for translation-related proteins (e.g. ribosomal proteins and amino-acyl tRNA synthetases) and moderate preference for metabolic enzymes. Furthermore, these two classes of proteins were found to be more prone to aggregation and/or inactivation in cells lacking IbpB under stress conditions (e.g. heat shock). Together, our in vivo data offer novel insights into the chaperone function of IbpB, or sHSPs in general, and suggest that the preferential protection on the protein synthesis machine and metabolic enzymes may dominantly contribute to the well known protective effect of sHSPs on cell survival against stresses. 相似文献
5.
6.
Emilie Pondeville Jean-Philippe David Emilie Guittard Annick Maria Jean-Claude Jacques Hilary Ranson Catherine Bourgouin Chantal Dauphin-Villemant 《PloS one》2013,8(12)
In insects, the steroid hormone 20-hydroxyecdysone (20E) coordinates major developmental transitions. While the first and the final steps of 20E biosynthesis are characterized, the pathway from 7-dehydrocholesterol to 5β-ketodiol, commonly referred as the “black box”, remains hypothetical and whether there are still unidentified enzymes is unknown. The black box would include some oxidative steps, which are believed to be mediated by P450 enzymes. To identify new enzyme(s) involved in steroid synthesis, we analyzed by small-scale microarray the expression of all the genes encoding P450 enzymes of the malaria mosquito Anopheles gambiae in active steroidogenic organs of adults, ovaries from blood-fed females and male reproductive tracts, compared to inactive steroidogenic organs, ovaries from non-blood-fed females. Some genes encoding P450 enzymes were specifically overexpressed in female ovaries after a blood-meal or in male reproductive tracts but only three genes were found to be overexpressed in active steroidogenic organs of both females and males: cyp307a1, cyp4g16 and cyp6n1. Among these genes, only cyp307a1 has an expression pattern similar to other mosquito steroidogenic genes. Moreover, loss-of-function by transient RNAi targeting cyp307a1 disrupted ecdysteroid production demonstrating that this gene is required for ecdysteroid biosynthesis in Anopheles gambiae. 相似文献
7.
Continuous cell cultures were established from imaginal wing discs of 2 Lepidoptera, Spodoptera frugiperda and Plodia interpunctella. The S. frugiperda line (IAL-SFD1) grows as multicellular vesicles and responds morphologically and biochemically to the insect hormone, 20-hydroxyecdysone. In contrast, the P. interpunctella cells (IAL-PID2) grow as attached monolayers of small spindle-shaped cells and do not appear to have specific responses to 20-hydroxyecdysone, although growth rates are slowed in these cells upon exposure to the hormone. 相似文献
8.
《Insect Biochemistry》1986,16(1):33-40
Normal-phase and reversed-phase thin-layer chromatographic systems for the separation and analysis of [3H]metabolites of 20-hydroxyecdysone have been developed. These include separations involving multiple development (in one or more solvent systems), two dimensional techniques, reversed-phase and ion-pair chromatography. Using these systems, the resolution and identification of the major metabolites of 20-hydroxyecdysone, produced following the injection of tritiated hormone into adult male Locusta migratoria, have been demonstrated. 相似文献
9.
Anna T. Curtis Masahiro Hori Janell M. Green William J. Wolfgang Kiyoshi Hiruma Lynn M. Riddiford 《Journal of insect physiology》1984,30(8):597-606
The absence of juvenile hormone at the time of head cap slippage during the last-larval moult of the tabacco hornworm, Manduca sexta, causes deposition of premelanin granules into the outer regions of the newly forming endocuticle beginning 13 h later. These granules were found to contain an inactive phenoloxidase which becomes activated about 9 h later, 4 h before body melanization begins. The onset of melanization was not accelerated by melanization and reddish colouration hormone from Bombyx heads, extracts of pharate-adult corpora cardiaca or pharate-larval ventral nerve cords (sources of eclosion hormone), or extracts of pharate-larval suboesophageal ganglia or corpora cardiaca-corpora allata complexes. Instead the fall of the ecdysteroid titre to below 250 ng/ml 20-hydroxyecdysone equivalents appeared to be the cue that allowed melanization about 4.5 h later. Up to, but not after, this time both melanization and ecdysis could be delayed by exogenous 20-hydroxyecdysone in a dose-dependent fashion above 0.1 μg per larva. In vitro studies published elsewhere indicate that 20-hydroxyecdysone prevents the activation of the premelanin granules. Thus the granules can be deposited at the proper time in the newly forming endocuticle but their melanization is regulated by the declining ecdysteroid titre and it thus synchronized with other events occurring just before ecdysis. 相似文献
10.
G. Laganà S. Giacobbe C. Mannucci S. Ficarra U. Leuzzi 《Journal of experimental marine biology and ecology》2007,349(1):27-34
In Pontonia pinnophylax (Otto), a crustacean decapod inhabiting the mantle cavity of Pinna nobilis L. (Bivalvia: Pteriomorpha), the lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) activity, and their electrophoretic patterns, were compared in relation to heat and urea inactivation. Activity was higher in LDH than in MDH, and the electrophoretic patterns showed a predominance of LDH-A4 and the presence of both mitochondrial and cytosolic MDH. Heat incubation reduced both enzymatic activities, but more MDH. Also all isozymes showed different heat sensitivity, with anodic forms more heat-resistant than cathodic ones, either in LDH as in MDH. Urea treatment caused also a higher inactivation of the most cathodic isozymes, but MDH appeared more resistant than LDH at 2 M urea. The high polymorphism of these enzymes suggests an adaptation of Pontonia metabolism to hypoxic conditions; moreover, the different isozyme stability grade should be functional to contrast environmental variability. 相似文献
11.
Implanting ovaries or injecting 20-hydroxyecdysone into male houseflies induced sex pheromone production, including (Z)-9-tricosene (muscalure), 9,10-epoxytricosane and (Z)-14-tricosen-10-one, which normally occurs only in vitellogenic females. Control males did not produce detectable amounts of these compounds. Injection of 20-hydroxyecdysone (5 μg/insect per day) for 3 days resulted in the accumulation of 1.81 μg/insect of (Z)-9-tricosene, 0.97 μg/insect of 9,10-epoxytricosane and 0.12 μg/insect (Z)-14-tricosen-10-one. Multiple injections of 20-hydroxyecdysone at doses as low as 50 ng resulted in the accumulation of 23:1, C23 epoxide and C23 ketone; shifted the distribution of label within the alkenes from 27:1 to 23:1 and decreased the amount of label in the hydrocarbon fractions as alkenes. Structures of the C23 alkene and epoxide produced by the males were verified by gas chromatography-mass spectrometry. Radioactivity from [1-14C] acetate was incorporated into the C23 alkene, epoxide and ketone in male insects after ovaries were implanted or they were injected with 20-hydroxyecdysone. Synthesis of the C23 pheromone components decreased rapidly within several days after the administration of 20-hydroxyecdysone ceased, indicating that the enzymes involved in sex pheromone production were not permanently induced by hormone treatment. Ecdysone was also effective in initianing pheromone production in males, whereas inokosterone and cholesterol were not effective. Data presented demonstrate that male houseflies possess the metabolic capability to produce the sex pheromone components, and this suggests that 20-hydroxyecdysone alters the production of cuticular hydrocarbons such that the C23 sex pheromone components become major products. 相似文献
12.
The effect of various duration of heat stress (38°C) on the activity of ecdysone 20-monooxygenase converting ecdysone into 20-hydroxyecdysone has been studied in D. virilis of wild type and mutant strain females, which differ by the mode of heat stress response of ecdysone and 20-hydroxyecdysone. We are the first to show that heat stress induces activity of ecdysone 20-monooxygenase in Drosophila females and enzyme activity correlates with the level of 20-hydroxyecdysone. 相似文献
13.
《Insect Biochemistry》1984,14(6):691-695
Intracellular and extracellular concentrations of cyclic GMP were measured under different conditions in cultures of two 20-hydroxyecdysone sensitive clones of Drosophila melanogaster. Exponentially growing cells maintained a concentration of 0.15 pmol/106 cells inside the cells (about 10−6 M) and 5 pmol/106 cells in the medium. When the medium was changed equilibrium was restored in the cells in about 15 hr. Addition of 20-hydroxyecdysone arrested growth and induced several enzymes and morphological modifications. It also increased (up to 10-fold) both intracellular and extracellular cyclic GMP levels depending on the amount of hormone. The ratio of the two levels remained constant. 相似文献
14.
Moulting hormone levels for all stages of the life cycle of the desert locust, Schistocerca gregaria, have been determined using gas chromatography with electron capture detection of the trimethylsilylated hormones. During larval development, the major hormone detected is 20-hydroxyecdysone with smaller quantities of ecdysone present. In mature adult females the major ecdysteroid observed is a polar conjugate of ecdysone, with smaller quantities of conjugated 20-hydroxyecdysone also present. During embryonic development the pattern changes from a high proportion of conjugated ecdysone in the early stages to give more free hormone and a higher proportion of 20-hydroxyecdysone in later stages. The highest titre of 20-hydroxyecdysone found in this insect is during the 5th larval instar. Maximal levels of ecdysteroid per insect are found in mature females just before oviposition, while the highest level of ecdysteroid per g of tissue is found in the eggs. 相似文献
15.
Moulting hormone levels in whole bodies of 5th instar S. gregaria were determined throughout the 5th larval instar using gas chromatography with electron capture detection of the derivatized hormone. No differences were found between hormone levels in insects in the gregarious and solitary phase. No evidence for the existence of polar ecdysteroid conjugates used for storage or transport of these hormones was found. Approximately one tenth of the 20-hydroxyecdysone observed in the gregarious insects was detected in the faeces, almost equally divided between free hormone and polar conjugates of it. 相似文献
16.
The allatostatic effect of 20-hydroxyecdysone on the adult viviparous cockroach, Diploptera punctata
Thomas Friedel René Feyereisen Eric C. Mundall Stephen S. Tobe 《Journal of insect physiology》1980,26(10):665-670
The effect of 20-hydroxyecdysone upon the activity of corpora allata (CA) from female Diploptera punctata has been investigated. This ecdysteroid inhibits juvenile hormone (JH) biosynthesis by the CA, whether they have been implanted into a male, or remained in situ within the female. In the female, this inhibition is reflected in reduced oöcyte growth and vitellin content. The allatostatic effect of 20-hydroxyecdysone becomes apparent in vivo within 24 hr. However, no inhibition was observed when the CA were maintained in vitro for 42 hr in medium containing up to 1·10?5 M 20-hydroxyecdysone. This suggests that the effect of the hormone upon the CA is indirect. These experiments raise the possibility that ecdysteroids play an allatostatic role during the normal gonotrophic cycle in Diploptera. 相似文献
17.
Larvae of the tobacco budworm,Heliothis virescens, are resistant to high levels of ingested 20-hydroxyecdysone which could cause potential inhibition to the development of
many other lepidopteran species. This resistance is attributed to the ability of the larvae to metabolize this molting hormone
to its 22-acyl ester forms. When tobacco budworm larvae were fed large quantities of 20-hydroxyecdyone, the hormonal metabolites
were found in gut and fat body tissues. When incubated with 20-hydroxyecdysone gut tissue converted 20-hydroxyecdysone into
its 22-acyl ester metabolites. Lumen site of the midgut was found to be the major location of this bio-transformation. In
contrast, fat body tissue failed to convert 20-hydroxyecdysone to 22-acyl ester metabolitesin vitro. After the oral injection of3H-ecdysone, the major metabolites formed were ecdysone 22-acyl esters whereas the majority of3H-ecdysone was transformed to polar metabolites after it was injected into the hemocoel of the larvae. Similar distributions
of ecdysteroid 22-O-acyltransferase and alkaline phosphatase activity in subcellular fractions demonstrates the co-localization of these enzymes
in plasma membrane of the gut epithelial cells. These results suggest that gut brush border membrane is the major site of
ecdysteroid 22-acyl ester formation inH. virescens larvae. 相似文献
18.
19.
Heat shock is a routine method used for inducible gene expression in animal models including zebrafish. Environmental temperature plays an important role in the immune system and infection progression of ectotherms. In this study, we analyzed the impact of short-term heat shock on neutrophil function using zebrafish (Danio rerio) as an animal model. Short-term heat shock decreased neutrophil recruitment to localized Streptococcus iniae infection and tail fin wounding. Heat shock also increased random neutrophil motility transiently and increased the number of circulating neutrophils. With the use of the translating ribosome affinity purification (TRAP) method for RNA isolation from specific cell types such as neutrophils, macrophages and epithelial cells, we found that heat shock induced the immediate expression of heat shock protein 70 (hsp70) and a prolonged expression of heat shock protein 27 (hsp27). Heat shock also induced cell stress as detected by the splicing of X-box binding protein 1 (xbp1) mRNA, a marker for endoplasmic reticulum (ER) stress. Exogenous expression of Hsp70, Hsp27 and spliced Xbp1 in neutrophils or epithelial cells did not reproduce the heat shock induced effects on neutrophil recruitment. The effect of heat shock on neutrophils is likely due to a combination of complex changes, including, but not limited to changes in gene expression. Our results indicate that routine heat shock can alter neutrophil function in zebrafish. The findings suggest that caution should be taken when employing a heat shock-dependent inducible system to study the innate immune response. 相似文献
20.
《Insect Biochemistry》1986,16(1):255-262
Vitellogenin (yolk protein) gene expression in the mosquito was investigated at the level of mRNA using a subcloned fragment (403-1c) of the vitellogenin DNA derived from an Aedes aegypti genomic library. Message appeared 1–3 hr after a blood meal, peaked at 36 hr and was rapidly degraded thereafter. Fluctuations in levels of 20-hydroxyecdysone after a blood meal coincided with accumulation of vitellogenin message. Blood-fed, decapitated females injected with 5 μg of 20-hydroxyecdysone accumulated up to 75% of the message found in blood-fed controls. Fat bodies from non-blood-fed females incubated with physiological levels of 20-hydroxyecdysone and the juvenile hormone analog methoprene contained twice as much vitellogenin message as those incubated with 20-hydroxyecdysone alone. Methoprene alone had no effect. 相似文献