摘要:

AbstractProtein, nucleic acids, and nucleotide syntheses were studied in pea aphids,Acyrthosiphon pisum(Harris), by feeding them labeled14C‐amino acids and [5‐3H]‐orotic acid in sucrose. It was demonstrated that in the absence of dietary essential amino acids, aphids were capable of synthesizing nucleic acids, nucleotides, and proteins when provided with a single dietary amino acid in sucrose. It is suggested that other required amino acids were possibly supplied by the symbionts present in the pea aphid and/or were obtained from the amino acid pool in the hemolymph or glucose, one of the end products of sucrose digestion. Of the various amino acids tested, synthesis of measurable amounts of protein or other compounds occurred when alanine, aspartic acid, glutamic acid, glycine, proline, or serine were provided, but no synthesis occurred with cys

ISSN:0739-4462    

DOI:10.1002/arch.940040302

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe binding and accumulation of the chitin synthesis inhibitor diflubenzuron (DFB) by a cell line derived from embryonic tissue of the tobacco hornworm,Manduca sexta(L.), was analyzed. A rapid and reversible binding to viable and nonviable cells suspended in the culture medium was observed at soluble concentrations of DFB for short exposure periods. Scatchard analysis gave no indication of a saturable uptake mechanism. The DFB‐binding capacity of intact cells was found to be similar to that of a crude membrane preparation (70,000g pellet); however, plasma membrane‐enriched fractions bound almost three times as much DFB as the homogenate. Repetitive shorttime incubations (up to 3 h) of suspended cells with DFB resulted in a stepwise intracellular accumulation of DFB. Treatment of growing cells with DFB at high concentrations (50 μM) of DFB for longer periods (up to 7 days) resulted in elevated intracellular accumulation of DFB, which exceeded the binding capacity of the cell membranes and the aqueous solubility of DFB. These results indicate that the intracellular crystals detected by transmission electron microscopy are precipitated DFB. No metabolites or other chemically modified products of intracellular DFB were detected by high pressure liquid chromatography (HPLC) after a 7‐day incu

ISSN:0739-4462    

DOI:10.1002/arch.940040303

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

年代:1987

数据来源: WILEY

摘要:

AbstractMaturing eggs (48 to 64 h old) of the tobacco hornworm,Manduca sexta, contain at least three ecdysteroid conjugates, two of which have been previously identified as 26‐hydroxyecdysone 26‐phosphate (the major conjugate) and 26‐hydroxyecdysone 22‐glucoside. In this study we have isolated and identified the third conjugate as 26‐hydroxyecdysone 2‐phosphate by XAD‐2 chromatography, C18SEP‐PAK separation, ion suppression reversed‐phase high‐performance liquid chromatography, nuclear magnetic resonance, and fast atom bombardment mass spectrometry. This compound is the second most abundant conjugate of ovaries from 4‐day‐old adult females. The possible role for this ecdysteroid

ISSN:0739-4462    

DOI:10.1002/arch.940040304

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

年代:1987

数据来源: WILEY

摘要:

AbstractA high‐molecular‐weight protein, Mr500,000, has been isolated and characterized from the hemolymph of the migratory locust,Locusta migratoria. It is composed of six seemingly identical subunits of apparent Mr78,000. It contains low concentrations of carbohydrate and lipid, but high percentages of aspartate and glutamate as well as high proportions of hydrophobic amino acid residues. An antiserum, developed against this purified hemolymph protein, does not react in the double‐diffusion test or after immunoblotting with purified lipophorin or cyanoprotein, two other major proteins in locust hemolymph. The concentration of this larval specific protein in the hemolymph ofLocustawas examined during the last larval instar and in adult males by quantitative rocket immunoelectrophoresis. Its concentration increases in the second half of the fifth instar, concommitant with an increase in total protein. The protein is detectable by immunological techniques in adults, although its concentration is very low at this

ISSN:0739-4462    

DOI:10.1002/arch.940040305

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

年代:1987

数据来源: WILEY

摘要:

Abstract[14C]DDT was used as a probe to determine the subcellular localization of DDT in the ventral nerve cord (VNC) of the cockroach,Periplaneta americana(L.). Male cockroaches were injected intra‐abdominally with [14C]DDT and their VNCs removed at 1 h post‐injection. The VNCs were then subjected to homogenization and differential centrifugation to isolate plasma membrane, mitochondrial, and microsomal fractions. Results indicate that the plasma membrane fraction contained the greatest amount of [14C]DDT, with the mitochondrial and microsomal fractions containing significantly less. Calculations and a comparison with I50values for oligomycin‐sensitive (OS)Mg‐ATPase from the literature support the prediction that an insufficient amount of DDT reaches the ventral nerve cord mitochondria of a cockroach to effect an I50level of inhibition of the (OS)Mg

ISSN:0739-4462    

DOI:10.1002/arch.940040306

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

年代:1987

数据来源: WILEY

摘要:

AbstractMethanol extracts of locust brains, corpora cardiaca (CC), and suboesophageal ganglia (SOG) were separated by gradient and/or isocratic reverse‐phase high‐performance liquid chromatography (HPLC) and allatotropic activity monitored in the eluted fractions. A major peak of activity, separated by isocratic separation with 12% 2‐propanol, designated allatotropin I, exhibited identical retention times in the three tissue extracts. Doseresponse curves of allatotropin I indicate similar content in brain and CC‐equivalents, whereas optic lobes, similarly separated by isocratic HPLC, contain only one‐tenth of this amount of allatotropin. Allatotropin I is resistant to boiling and is susceptible to tryptic and chymotryptic digestion. Methanol extracts of thoracic muscle, Malpighian tubules, fat body or ovaries, similarly prepared and boiled, did not exhibit allatotropic activity at high doses of tissue eq

ISSN:0739-4462    

DOI:10.1002/arch.940040307

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

年代:1987

数据来源: WILEY

摘要:

AbstractHeat shock induced by an increase in temperature from 30°C to 47°C led to changes in protein synthesis in wing pads of the fifth larval instar ofLocusta migratoria. Synthesis of heat shock proteins in the molecular weight range of 85,000, 70,000 and 18,000–22,000 was first detected at a threshold temperature of 45°C and was found to be highest at 47°C. A marked decline in the synthesis of many other proteins was also evident at 47°C. Recovery of general protein synthesis was observed when wing pads were shifted back to 30°C after a 2‐h heat shock at 47°C. Heat shock protein patterns inLocustaandDrosophilawer

ISSN:0739-4462    

DOI:10.1002/arch.940040308

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

年代:1987

数据来源: WILEY

摘要:

AbstractAn insulin‐like peptide (ILP) extracted from midgut of 25‐day‐old male adultLocusta migratoriacan modify the relative activity of the two main pathways of glucose catabolism. The effect of ILP on the activity of the pentose cycle and the glycolytic‐citric acid cycle inLocusta migratoriawas evaluated by a radiorespirometric method by means of [1‐14C] glucose and [6‐14C]glucose as substrates. The time course of the ILP effect was determined. The insulin‐like peptide increases the relative activity of the pentose cycle. This effect is rapid and of short duration. Injected mammalian insulin has a s

ISSN:0739-4462    

DOI:10.1002/arch.940040309

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

年代:1987

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940040310

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

年代:1987

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940040301

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

年代:1987

数据来源: WILEY