摘要:

AbstractIn adult femaleLocusta migratoria, at about day 8 after eclosion, when vitellogenin (Vg) is first produced as a result of induction by juvenile hormone (JH), the intensity of hemolymph protein electrophoretic bands at about 75 kDa and 20 kDa increases sharply, suggesting that JH may induce additional proteins. A major component of the elevated protein is persistent storage protein (PSP; subunit 74 kDa). Administration of the JH analog, methoprene, to precocene‐treated adult locusts was followed by a rise in hemolymph levels of PSP but not in apolipophorin III (19 kDa), identified immunochemically and electrophoretically. The synthesis of PSP in adult fat body was confirmed by incorporation of [3H]leucine. At 48 h after treatment with methoprene, Vg synthesis was induced in females (as previously observed) and synthesis of PSP in both sexes was elevated above controls, while synthesis of apolipophorin III was not stimulated. We conclude that in adult locust fat body the synthesis of several proteins responds in different ways to the JH analog: Vg (and a 21 kDa protein described elsewhere) is induced de novo solely in females; PSP (and a 19 kDa protein described elsewhere) is stimulated in both sexes but is not fully JH‐dependent; apolipophorin III is not stimulated. In these experiments, methoprene was administered both by injection in mineral oil and topically in acetone. After injection of mineral oil as a vector control, incorporation into secreted proteins was stimulated at 24 h, presumably due to a wound effect; topical application of acetone avoids this effect and is a preferred route for administration of JH analog. © 1992 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/arch.940200302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

Abstract3,4‐Dihydroxyphenylalanine, 5‐6‐dihydroxyindole, and N‐acetylarterenone were detected by electrochemical methods in the hemolymph of immune reactive larvae ofDrosophila melanogasterfollowing parasitization by the waspLeptopilina boulardi. Determinations of the catechols were made after separation by reverse phase, ion‐pairing high pressure liquid chromatography with electrochemical detection. The presence of 5,6‐dihydroxyindole unequivocally establishes the eumelanin pathway in the defense reponse ofDrosophila, and confirms previous investigations which have implicated certain catecholamine metabolizing enzymes in insect immunity. The occurrence of N‐acetylarterenone, a derivative of the principal sclerotizing agent N‐acetyldopamine, verifies the existence and proposed involvement of quinone methide isomerase in the regulation of catecholamine metabolism, and suggests that the cellular capsule formed byDrosphilain immune reactions against parasites is most likely a composite of both eumelanin and sclerotin. The absence of 3,4‐dihydroxyphenylacetic acid in hemolymph samples from immune reactive hosts suggests that during parasitization certain catecholamines and metabolic precursors may be re‐employed in alternate pathways, some of which may be used in defense reactions. ©

ISSN:0739-4462    

DOI:10.1002/arch.940200303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe protocerebral neurosecretory cells previously shown to be the source of the myotropin controlling ovulation inRhodnius prolixusreact in an immunocytochemical assay using an antiserum against FMRFamide. When the same antiserum was injected into fed mated females at the appropriate time the timing of oviposition was delayed, but the total number of eggs developed was unaffected compared to controls injected with pre‐immune rabbit serum. The titer of FMRFamide‐like peptide (assayed by RIA) in the hemolymph of mated and virgin females was found to fluctuate with the egg laying cycle, and to reflect earlier determinations of the titer of myotropic activity. Western blots of SDS‐PAGE revealed a FMRFamide‐immunoreactive peptide of approximately 8.5 kDa in both hemolymph and extracts of the ovulation hormone cells. © 1992 Wiley

ISSN:0739-4462    

DOI:10.1002/arch.940200304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe effects of diet and different constant temperatures on hemolymph cation concentrations (Na+, K+, Mg2+, Ca2+) have been studied inMorimus funereuslarvae collected from natural habitat, fed natural (oak or beech bark) or artificial diet, as well as in larvae reared from hatching on an artificial diet. In the hemolymph of larvae maintained under natural conditions Mg2+was dominant, whereas Na+concentration was very low. In their natural diets concentrations of Na+and K+were very low, while those of Ca2+and Mg2+were high. In larvae continuously reared on an artificial diet, hemolymph Mg2+concentration was significantly decreased and Na+concentration increased more than fourfold compared to the results obtained in oak‐fed larvae. Na+and K+are the dominant cations in the artificial diet. The concentrations of K+and Ca2+in the hemolymph of larvae fed natural or artificial diet are nearly identical, suggesting the existence of an internal regulatory mechanism in this insect for these cations. The hemolymph cation concentrations ofM. funereuslarvae are predominantly dependent upon the diet consumed, much less upon the environmental temperatures. The most stable concentrations of cations were observed in larvae continuously fed an artificial diet and exposed to different constant temperatures. There was much less stability in the hemolymph cation concentration in oak larvae fed either natural or artificial food after their transfer to constant temperatures. With respect to the response to the external factors studied, the most sensitive are the Na+concentrations, the most stable seems to be K+. © 1992 Wiley‐Liss,

ISSN:0739-4462    

DOI:10.1002/arch.940200305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe role of proctolin has been further investigated in the locust (Locusta migratoria) mandibular closer muscles. Radioactive calcium uptake measurements were made using protease‐dissociated muscle cells. Both the phorbol ester, phorbol‐12, 13‐dibutyrate, and proctolin produce tonic contractions which are associated with the influx of extracellular calcium. The thresholds for proctolin and the phorbol ester to contract the muscle were 1‐10 nM and 10‐100nM, respectively, while their respective thresholds for evoking measurable calcium influx into the muscle cells were 0.1‐1 nM for proctolin, and 0.1‐1 pM for phorbol‐12, 13‐dibutyrate. The effect of phorbol‐12, 13‐dibutyrate is blocked by a number of protein kinase inhibitors (at a concentration of 0.1 mM), suggesting that an activation of protein kinase can lead to calcium influx. These inhibitors, however, do not block the effect of proctolin, indicating that these two compounds work through different pathways, possibly coverging on the same final target. In light of this finding, a number of other compounds have been tested to try to ascertain how proctolin mediates an increased calcium influx.

ISSN:0739-4462    

DOI:10.1002/arch.940200306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractJuvenile hormone esterase (JHE) activity in the hemolymph of 5th‐instarHeliothis virescenslarvae injected withMicroplitis croceipesteratocytes was inversely related to the number of teratocytes injected. JHE activity in the hemolymph of larvae injected with 750 3‐day‐old teratocytes (the approximate number from one parasitoid embryo) was depressed to less than 5% of those levels found in control larvae. During the latter portion of the digging stage and in the burrowing‐digging (BD) stage JHE activity in larvae treated with 350 teratocytes was approximately 40% of control values. However, injection of 180 teratocytes did not significantly affect JHE titers. Two‐day‐old teratocytes caused the greatest reduction in JHE titer with decreasing effects observed with injections of 3‐ to 6‐day‐old teratocytes. Nevertheless, because 2‐day‐old teratocytes were difficult to separate from host hemocytes, 3‐day‐old teratocytes were used in most of these studies. Injections of nonparasitizedH. virescenshemolymph plasma,Micrococcus luteusbacterial cell walls, washedM. croceipeseggs, or teratocytes fromCotesia congregatadid not depress JHE titers. Teratocyte injections also significantly reduced growth of host fat body. Ecdysteroid titers in cell formation, day 2 (CF2) larvae injected as new 5th instars with 350 3‐day‐old teratocytes failed to increase, as compared to noninjected and saline‐injected controls. An injection of 1 μg/larva of 20‐hydroxyecdysone at the BD stage permitted normal pupation in 50% of the teratocyte‐treated larvae as compared to 0% pupation for teratocyte‐treated control larvae not treated with 20‐hydroxyecdysone. Teratocytes seem to be responsible for the inhibition of JHE release and thus indirectly impact on ec

ISSN:0739-4462    

DOI:10.1002/arch.940200307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940200301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY