摘要:

AbstractTwo molecular forms of juvenile hormone binding proteins were identified in the larval hemolymph ofBombyx moriby photoaffinity labeling. One form having an Mr of 33 kDa was present constantly in the hemolymph of the third to the fifth instar larvae while the other form having an Mr of 35 kDa was detected in the hemolymph until in the early fifth instar larvae but not in the prewandering larvae and prepupae.A 33 kDa binding protein was purified by hydrophobic interaction chromatography, gel filtration, and native PAGE. Antiserum against 33 kDa binding protein cross‐reacted with 35 kDa binding protein on Western blots, suggesting that these binding proteins shared the same epitopes. From the results of saturation binding assays, it was inferred that 33 and 35 kDa binding proteins had a similar binding affinity for JH 1.It was revealed that one of these binding proteins, 35 kDa binding protein, was produced in the fat body in a stage‐specific manner: fat body of the early fifth instar larvae synthesized both 33 and 35 kDa binding proteins while that of prewandering larvae synthesized only 33 kDa binding protein. © 1996 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<83::AID-ARCH1>3.0.CO;2-Y

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

年代:1996

数据来源: WILEY

摘要:

AbstractThe ability of midgut extracts of the keratinophagous larva,Hofmannophila pseudospretella(Lepidoptera: Oecophoridae), to catalyse degradation of wool was studied in vitro. A high rate of degradation was observed under anaerobic conditions in the presence of a reducing agent at pH 9.2 and at an oxidation‐reduction potential of −200 to −350 mV, values comparable to those observed in vivo. Rates were sensitive to the oxidation‐reduction potential and the nature of the reductant, being higher for sulphydryl compounds than for other sulfur‐based reducing agents and inversely related to the oxidation‐reduction potential for both classes of compounds. Degradation was measured as a two‐step process involving reduction/solubilization of wool proteins followed by proteolysis. The initial step was shown to occur via two pathways, enzymic and non‐enzymic. The enzymic pathway was the major route in vitro and was characterized by a requirement for a heat‐unstable, high molecular weight fraction of the larval midgut extract as well as a reducing agent for maximum rates. The possible nature of this activity and its in vivo importance are discussed. © 19

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<99::AID-ARCH2>3.0.CO;2-S

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

年代:1996

数据来源: WILEY

摘要:

AbstractTo evaluate the ecdysteroid‐like mode of action of tebufenozide (RH‐5992), the effects on the fine structure of the integument in last‐ and third‐instar larvae of the beet armyworm,Spodoptera exigua, and on cuticle formation in cultured imaginal wing discs, were studied. After 3 h of treatment with tebufenozide, the first signs of a normal moult were observed in treated larvae. A few hours later, ecdysial space formation and secretion of a new epicuticle were started. Furthermore, the new cuticle was incomplete in treated larvae; the new procuticle was absent or contained only a very low number of lamellae. In addition, epidermal cells showed many vacuoles and symptoms of degeneration with increase in time. Only a few lamellae of the old procuticle were digested, and normal ecdysis was inhibited which led to the presence of a double cuticle within 24–48 h after treatment. Similarly, cultured discs were stimulated to deposit a new cuticle within 12 h after cultivation in a medium containing tebufenozide. Our observations in treatedS. exigualarvae on the one hand and in imaginal discs cultured with tebufenozide on the other hand are indicative of a hyperecdysteroid action, and confirm that the moult accelerating mode of action of tebufenozide resulted in a forced, untimely synthesis of cuticle by activation of epidermal or epithelial cells, and that its ecdysis inhibitory activity is mediated by its effect on post‐apolysis processes. © 1996 Wil

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<121::AID-ARCH3>3.0.CO;2-0

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

年代:1996

数据来源: WILEY

摘要:

AbstractBiosynthesis of the unusual sex pheromone component (Z)‐5‐tetradecenyl acetate (Z5‐14:OAc) was studied in the tortricid moth,Ctenopseustis herana(Felder&Rogenhofer), by fatty acid methyl ester (FAME) analysis of the pheromone gland, and topical application of various deuterium‐labelled acids to the gland. The only unusual unsaturated FAME found in base‐methanolyzed glands of females was the putative precursor of the pheromone, methyl (Z)‐5‐tetra‐decenoate (Z5‐14:Me). When deuterium‐labelled, myristic, palmitic, stearic, lauric, and oleic acids were applied to the gland, label was incorporated into the pheromone component only from the first three acids (i.e., Z5‐14:OAc could not be biosynthesized from lauric or oleic acids). Furthermore, the amount of label incorporated from the first three acids decreased in the order myristic>palmitic>stearic. Application of labelled myristic acid to the gland resulted in incorporation of label into Z5‐14:Me. These data are consistent with the biosynthesis of Z5‐14:OAc inC. heranaresulting from Δ5‐desaturation of myristic acid, a novel biosynthetic route for a moth sex pheromone component. Regulation of pheromone biosynthesis in this species was also investigated. Decapitation of femaleC. heranaresulted in a significant decline in sex pheromone titre. Injection of female head extract or syntheticBombyx moripheromone biosynthesis‐activating neuropeptide (PBAN) into decapitated femaleC. heranagave a significant increase in pheromone titre, suggesting that pheromone biosynthesis in this species is regulated by a PBAN or PBAN‐like s

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<135::AID-ARCH4>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:

AbstractThe storage proteins of Lepidoptera include a pair of methionine‐rich hexamerins (MtH) that are more abundant in female pupae than in males. Their inferred support of female reproduction could be achieved either by enhancing general pools of amino acids, or by hydrolyzing MtH at times and/or sites that direct its constituents to the synthesis of egg proteins. The two models were tested inActias luna, a saturniid moth that makes its eggs during adult development. MtH and arylphorin (ArH), the third major storage protein of this species, were labeled metabolically with [35S]‐methionine and [3H]‐leucine, and injected individually into wandering stage caterpillars. Isotope distributions at eclosion indicated that both hexamerins supported egg formation as well as adult tissue protein synthesis. In the absence of evidence for targeting, MtH appears to support egg formation inA. lunaby enhancing the amino acid pools derived from ArH. Analysis of35S labeling and of35S/3H ratios indicated, however, that ArH is consumed over a period that extends somewhat later in adult development than MtH. Differences in timing should prove to be much greater in Lepidoptera that delay egg formation until after eclosion. © 1996 Wiley‐L

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<149::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:

AbstractLarval midgut extracts from the noctuidSesamia nonagrioidesLef. were assayed for protease activity. Total proteolytic activity, as measured by azocasein hydrolysis, showed a pH optimum in the range 10.0 to 11.5, suggesting a digestive system based largely on serine‐like proteases. The ability of midgut extracts to hydrolyze specific synthetic substrates, the elucidation of the pH at which maximal hydrolysis occurs, and their sensitivity to protease inhibitors confirmed the presence of the serine endoproteases: trypsin, chymotrypsin, and elastase; and the exopeptidases: carboxypeptidase A, carboxypeptidase B, and leucine aminopeptidase. The distribution of these digestive proteases along the gut sections and among the different midgut regions was examined. All types of endoproteases and exopeptidases were mainly located in the midgut, with less than 5% of the activity in the foregut and hindgut. When the two halves of the midgut were compared, all proteolytic activities were higher in the anterior portion of the midgut. Trypsin, chymotrypsin, elastase, and carboxypeptidase B activities were mainly located in the endoperitrophic space of the midgut, with some activity in the ectoperitrophic space, whereas aminopeptidase and carboxypeptidase A activities were preferentially located in the midgut epithelium. © 1996 Wiley‐Liss,

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)33:2<163::AID-ARCH6>3.0.CO;2-Z

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)33:2<::AID-ARCH940330201>3.0.CO;2-W

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

年代:1996

数据来源: WILEY