摘要:

AbstractSusceptibility of moths and larvae of cotton bollworm to ten different insecticides by topical application and their effect on enzymes involved in insecticide detoxification were determined. The moths were more susceptible than larvae to the insecticides tested, with the exception of pyrethroids and sulprofos. Combination of several insecticides with the synergists piperonyl butoxide (PB) and S,S,S‐tributylphosphorotrithioate (TBPT) showed that lower level of carbamate and organophosphate toxicity in larvae, as compared to moths, was the result of higher detoxification enzyme activities. Studies of the post‐treatment fate of14C‐labeled malathion and3H‐trans‐permethrin indicated that both the cuticular penetration, internal accumulation, and excretion of applied toxicants and their metabolites occurred more rapidly in larvae than in moths. The activities in vitro of esterases, glutathione S‐transferases, and monooxygenases were determined but there were no correlations with either toxicity of insecticides or synergistic effect for combination of insecticides with PB and TBPT in moths. © 1996 Wil

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<157::AID-ARCH1>3.0.CO;2-W

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

年代:1996

数据来源: WILEY

摘要:

AbstractHyperlipaemic response to adipokinetic hormone (AKH I) was demonstrated in both solitary and gregarious phases of the desert locust,Schistocerca gregaria gregaria.Time‐course studies showed that the gregarious locusts had a faster response to the hormone than their solitary counterparts. At peak response time (90 min), the gregarious locusts were more sensitive to AKH I doses below 2 pmol while the solitary locusts had a higher response above this dose. Upon injection of the hormone, lipoprotein conversion occurred, resulting in the formation of the low density lipoprotein (LDLp). The LDLp formed in the gregarious locusts was much larger than that of the solitary locusts. The fat body lipid reserve (expressed as % fat body dry weight) was significantly (P<0.01) higher in the gregarious (79.02 ± 2.77%) than in the solitary locusts (65.23 ± 2.55%). Triacylglycerol was the major lipid class representing 83.9 and 73.9% of the total lipids in gregarious and solitary locusts, respectively. The higher fat body lipid reserves and efficient LDLp formation in response to AKH in gregarious locusts compared to solitary locusts suggests a physiological adaptation for prolonged flights. © 1996 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<173::AID-ARCH2>3.0.CO;2-#

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

年代:1996

数据来源: WILEY

摘要:

AbstractExposure of insects and higher orders of animals to UVC radiation has been shown to result in toxicity with a delayed expression. We have observed an immediate writhing response in slowly wandering third instar larvae ofDrosophila melanogasterexposed to UVC radiation at doses that were not lethal. UVB and UVA radiation had no effect. Mutants for the visual and sensory systems appeared to respond normally, but CO2anesthesia resulted in reversible inhibition,ebonyandsilvermutants, which affect different pathways in catecholamine metabolism, showed an absent to reduced response. Using UVC lasers, we were able to demonstrate a response in different regions of the larval body. Furthermore, a 193 nm laser that penetrates only 2–5 μm was able to induce a response but unable to kill the larvae. These results suggest a photochemical reaction occurs in the cuticle which produces free radicals that stimulate the nerves and muscle which are present immediately below the epidermis. Possible targets for the UVC radiation are catecholic compounds secreted and processed into the cuticle of third instar larvae just prior to pupariation whose primary function is to crosslink the protein and carbohydrate components. © 1996 Wiley‐Liss

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<187::AID-ARCH3>3.0.CO;2-W

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

年代:1996

数据来源: WILEY

摘要:

AbstractWe describe a method for the purification of ferritin fromMusca domesticalarval hemolymph.Muscaferritin occurs in hemolymph predominantly as a native protein with molecular weight equal to 550,000 and subunits of 26,000. The average iron content of purified ferritin was determined to be 3,000 ± 600 iron atoms per molecule. The iron contents of ferritin was heterogeneous; both fully iron loaded molecules and apoferritin are probably present in theMuscahemolymph. The anti‐ferritin serum raised in rabbit was able to recognize native ferritin but was not reactive with the protein subunits isolated by SDS‐PAGE. The ferritin concentration in hemolymph attains a maximum of 0.28 mg/ml in the wandering stage larvae, decreasing to 0.13 mg/ml at the middle of pupal stadium. The ferritin contents of midgut and fat bodies were also determined. Fat body ferritin content is greatly reduced when the feeding larva passes into wandering stage. © 1996 Wiley‐Li

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<197::AID-ARCH4>3.0.CO;2-W

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

年代:1996

数据来源: WILEY

摘要:

AbstractAdenylyl cyclase activity in mealworm larval fat body and its dependence on external Ca2+concentrations and glucose catabolism pathways in vitro were analyzed for their response to intestinal insulin‐like peptide (ILP) and synthetic locust adipokinetic hormone I (AKH‐I). Dose‐response curve for cAMP accumulation was obtained with increasing doses of ILP. The effects of ILP were ten‐fold lower than those of AKH‐I. Forskolin and IBMX provoked very high levels of cAMP accumulation but IBMX did not potentiate the effects of ILP on cAMP accumulation. Accumulation of cAMP after a treatment with ILP involves a Ca2+influx via the opening of L‐type voltage gated channels. The cyclic AMP analogue chlorophenyl thio‐cAMP as well as AKH‐I induced a decrease in the utilization of the pentose cycle while the effects of ILP were totally opposite. Finally, the antagonism between ILP and AKH‐I on glucose metabolism results from a participation of different transduction pathways (Ca2+‐dependent and Ca2+‐independent, respectively), probably located in the same target cells, thus suggesting the involvement of mechanisms similar to those existing in mammals.

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<209::AID-ARCH5>3.0.CO;2-T

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

年代:1996

数据来源: WILEY

摘要:

AbstractProphenoloxidase (proPO) was purified from plasma of the locust,Locusta migratoria.This was achieved in three steps (gel filtration on 5300, anion exchange on QMA Memsep, and affinity chromatography on blue Trisacryl) without the use of anticoagulant buffer or inhibitors. The native protein had an apparent molecular mass of 250 kDa as determined by gel filtration and was likely composed of three non‐covalently associated subunits of 81 kDa. Its amino acid composition was found to be very similar to that ofBombyx moriproPO. Purified locust proPO could be converted into phenoloxidase (PO) by α‐chymotrypsin. Using L‐dopa as substrate, Kinand Vmaxwere determined to be 1.5 mM and 5 μM/s, respectively. © 1996 Wiley

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<225::AID-ARCH6>3.0.CO;2-X

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

年代:1996

数据来源: WILEY

摘要:

AbstractPrevious studies have shown that juvenile hormone esterase (JHE) activity and arylphorin titer were dramatically reduced in the hemolymph ofHeliothis virescenslarvae parasitized byMicroplitis croceipes. Similar changes were observed in calyx fluid‐injected or tetratocyte‐injected larvae. In this study, we showed that the mRNA levels of both JHE and arylphorin transcripts were reduced significantly in fat body of parasitized larvae compared to those in nonparasitized larvae. The reduction of mRNA level appears to be fat body‐specific, because no reduction of arylphorin mRNA level was observed in testes of the same parasitized larvae. Significantly, the mRNA levels of JHE and arylphorin in calyx fluid‐injected or teratocyte‐injected larvae were not different from those in control larvae, although the activity of JHE and the protein level of arylphorin were substantially lower in the treated larvae. Thus, our data suggest that both suppressed transcription of JHE‐ and arylphorin‐encoding genes and post‐transcriptional/translational modification(s) of JHE and arylphorin mRNAs or proteins may be involved in the reduction of JHE and arylphorin levels in parasitizedH. virescenslarvae. Calyx fluid and teratocytes may negatively regulate JHE and arylphorin levels via a transcriptional/translational mechanism. The factor(s) responsible for the reduction of JHE and arylphorin transcript levels by parasitization appears to be distinct from those induced by injection of calyx fluid or teratocytes. © 1996

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<237::AID-ARCH7>3.0.CO;2-V

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe correlation between triacylglycerols containing conjugated diene fatty acyl moieties and pheromone aldehydes in the sex pheromone glands of females ofManduca sextawas investigated. Females decapitated 15 h after adult emergence neither called nor produced pheromone during the natural period of pheromone production on the subsequent two nights. However, these females could be stimulated to produce sex pheromone for prolonged periods by repeated injection of synthetic pheromone biosynthesis activating neuropeptide (PBAN). Gas chromatographic analysis of methanolysis products of lipids extracted from the pheromone glands of decapitated and intact females showed no differences in the amounts of fatty acyl precursors of pheromone. High performance liquid chromatographic analysis of the triacylglycerols containing conjugated diene analogues of the pheromone components (diene TG), obtained 24 and 48 h after decapitation, showed that the total amounts of these components were not affected by decapitation. The amounts of all diene TG peaks declined significantly when decapitated females were stimulated to produce pheromone during a 7 h period by repeated injection of PBAN at 3 h intervals but recovered when pheromone production subsided. These results indicate that PBAN induces liberation of pheromone precursors from the triacylglycerols during pheromone biosynthesis but does not induce replenishment of this storage pool. © 1996 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of Amer

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<249::AID-ARCH8>3.0.CO;2-T

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe high molecular weight (680 KDa) glycolipoprotein from the haemolymph of male larvae ofAntheraea mylittaDrury (Lepidoptera: Saturniidae) was identified as lipophorin by gradient KBr ultracentrifugation and SDS‐PAGE. This lipophorin is composed of two subunits: apolipoprotein 1 (234 KDa) and apoprotein II (80 KDa). The density of the native molecule is 1.1941 g/ml. By weight, it contains 53.7% protein, 3.7% carbohydrate, and 42.6% lipid. Neutral lipids and phospholipids are 66.2 and 33.8% of the total lipids, respectively. Mannose and N‐acetylglucosamine are the only sugars detected by gas liquid chromatography. The amino acid composition of both the native molecule and its two subunits was determined, and yielded similar amino acid compositions. © 1996 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)32:2<261::AID-ARCH9>3.0.CO;2-0

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

年代:1996

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/1520-6327(1996)32:2<::AID-ARCH940320201>3.0.CO;2-1

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

年代:1996

数据来源: WILEY