摘要:

AbstractA wide spectrum of repetitive DNA amounts and interspersion patterns is seen in mosquitoes and other dipterans. Using a simple and rapid technique, we show that these range from a minimal amount in five species ofAnophelesthrough moderate amounts inCulex quinquefasciatusto large amounts inAedes aegyptiandStomoxys calcitrans.AlthoughCulexandAedesare closely related and both have a considerable amount of interspersed repetitive DNA, the repetitive sequences are different between the two genera. These results and previously published information show that the amount of repetitive DNA and sequences involved have changed many times during the evolution of the Diptera.

ISSN:0739-4462    

DOI:10.1002/arch.940100202

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

年代:1989

数据来源: WILEY

摘要:

AbstractTwo storage proteins, storage protein‐1 (SP1) and storage protein‐2 (SP2), were found in hemolymph and fat body during the development ofHyphantria cunea, the fall webworm. Both storage proteins show similiar quantitative changes during development in males and females; however, SP1 is more abundant. The hemolymph of last instar larvae contains high concentrations of the storage proteins. However, following pupation, the storage proteins accumulate in fat bodies. SP1 peaks in the hemolymph of males and females late in last instar larvae (8‐day‐old 7th instar larvae).SP1 has a native molecular weight of 460,000 and consists of six identical subunits (Mr = 76,700), while SP2 has a molecular weight of 450,000 and is composed of two different subunits (Mr = 74,100 and 72,400). Both SP1 and SP2 are hexamers and are phosphorylated glycolipoproteins. The pl values of SP1 and SP2 were determined to be 5.70 and 5.50, respectively.Antibodies raised against SP1 react positively with vitellogenin and ovary extract, as well as with proteins in the hemolymph from last instar larvae and proteins in pupal fat bodies. Storage protein synthesis starts in fat bodies of a 4‐day‐old 7th instar larvae and in female peaks at 6–8 days of t

ISSN:0739-4462    

DOI:10.1002/arch.940100203

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

年代:1989

数据来源: WILEY

摘要:

AbstractComplementary (c)DNA coding for an insect yolk protein, the egg‐specific protein of the silkwormBombyx moriwas cloned and the nucleotide sequence determined. The sequence covers the entire coding region of 1,677 base pairs with 5′ and 3′ noncoding regions (21 and 115 base pairs, respectively). The deduced amino acid sequence of the egg‐specific protein consists of 559 amino acid residues. The NH2‐terminal 18 amino acid sequence is enriched in hydrophobic amino acids and assumed to be a signal peptide. A sequence, Asn‐X‐Thr, a potential N‐linked glycosylation site, is found at positions 191 to 193. A serine‐rich domain is localized in the region from 63 to 90, in which phosphorylation takes place. Cys His motif in 405 to 415 is analogous to a proposed metal binding sequence. Lys132‐Asn133and Arg228‐Asp229are probably the sites cleaved by the egg‐specific protein protease that appears during embryogenesis. The derived amino acid sequence has no appreciable homology to o

ISSN:0739-4462    

DOI:10.1002/arch.940100204

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

年代:1989

数据来源: WILEY

摘要:

AbstractA rapid, efficient procedure for the isolation and purification of the vitellogenin binding protein from locust ovarian membranes is described. After solubilization with the nonionic detergent octyl‐β‐D‐glucoside and removal of the detergent, the binding protein is subjected to affinity chromatography on vitellogenin coupled covalently to Affi‐Gel 15. The binding protein is eluted with suramin and EDTA at low pH value. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis reveals a polypeptide with a molecular weight of 156,000 in the eluted fraction. By ligand blotting this polypeptide could be identified as the vitellogenin binding protein. It retains its high‐affinity binding properties. The specific binding of vitellogenin increases from 4.8 μg (intact ovarian membranes) to 170.9 μg (affinity purified binding protein) per mg membrane protein, which corresponds to a purification

ISSN:0739-4462    

DOI:10.1002/arch.940100205

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

年代:1989

数据来源: WILEY

摘要:

AbstractEffects of two biosynthetically distinct plant phototoxins—xanthototoxin, a furanocoumarin, and harmine, a β‐carboline alkaloid, which are known to produce toxic oxygen species—on the food utilization efficiencies and enzymatic detoxification systems of the polyphagous cabbage looper.Trichoplusia ni(Lepidoptera: Noctuidae), were studied. Newly molted fifth‐instar larvae were allowed 36 h to ingest diets containing these two phototoxins at 0.15% wet weight in the presence of near ultraviolet (UVA). The growth and development of the larvae, as well as the corresponding activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX), and glutathione reductase (GR) and the detoxification enzyme cytochrome P‐450, were measured. Xanthotoxin reduced rates of relative growth and consumption and efficiencies of conversion of ingested and digested food to biomass. Harmine reduced rates of growth and consumption without affecting efficiencies of conversion. Specific activities of SOD, CAT, GPOX, and GR of whole‐body homogenates in the absence of compounds were 0.88 units, 153μmol H2O2decomposed·mg protein−1·min—1, 38.3 nmol NADPH oxidized·mg protein−1·min−1, and 0.56 nmol NADPH oxidized·mg protein−1·min−1, respectively. SOD activity was induced 2.9‐fold and 3.8‐fold by dietary xanthotoxin and harmine, respectively. CAT and GPOX activities were induced 1.2‐fold by harmine only, and GR activity was not changed by either chemical. The P‐450 activity toward xanthotoxin in the microsomal fraction of midguts was low (0.15 nmol xanthotoxin metabolized·mg protein−1·min−1) and was not induced by xanthotoxin ingestion. These studies indicate that P‐450 and antioxidant enzyme systems may be independent but consequential, the induction of antioxidant enzymes by phototoxins occurring when low P‐450 activity toward the phototoxin permits the accumulation of oxidative stress from unmetabolized phot

ISSN:0739-4462    

DOI:10.1002/arch.940100206

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe α‐methylated derivatives of tryptophan, tyrosine, and dihydroxyphenylalanine were injected into cockroaches (Periplaneta americana). The levels of these compounds and those of dopamine, 5‐hydroxytryptamine, tyrosine, and tryptophan in the nervous tissue, hemolymph, and fat body were measured at various times after drug administration. Levels of 5‐hydroxytryptamine and tryptophan in the nervous tissue are significantly reduced by α‐methyltryptophan administration. Concentrations of dopamine in nervous tissue are reduced by α‐methyltyrosine administration. This effect also persists for several weeks, and α‐methyltyrosine is observed in the nervous tissue 3 weeks after injection. Levels of dopamine and 5‐hydroxytryptamine in the nervous tissue are unaffected by α‐methyldihydroxyphenylalanine, and this compound is less persistent in nervous tissue than α‐methyltyrosine or α‐methyltryptophan demonstrates that these compounds can be absorbed and affect amine levels in the nervous tissue when included in the diet. Inhibition of tryptophan hydroxylation by crude enzyme preparations of cockroach nervous tissue was demonstrated with both α‐methyltryptophan and α‐methyltyrosine, with α‐methyltryptophan being the more effective inhibitor. Aromatic amino acid decarboxylase activity toward dihydroxyphenylalanine in crude enzyme preparations of cockroach nervous tissue was strongly inhibited by α‐methyldihydroxyphenylalanine and monofluoromethyldihydroxyphenylalanine, slightly inhibited by α‐methyltyrosine and unaffected by α‐methyltryptophan at concentrations up to 10−3M. The results indicate that α‐methyltyrosine and α‐methyltryptophan, but not α‐methyldihydroxyphenylalanine, can selectively alter amine concentrations in insect nervous tissue and that insects are only poorly able to metabolize or excrete these compounds. The selective and long‐lasting depletion of dopamine or 5‐hydroxytryptamine by some of these compounds suggest that they may be useful in behavioral studies

ISSN:0739-4462    

DOI:10.1002/arch.940100207

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

年代:1989

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940100208

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

年代:1989

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940100201

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

年代:1989

数据来源: WILEY