摘要:

AbstractThe mandibular closer muscles of the cricket,Gryllus domestica, contain a 5‐hydroxytryptamine (5‐HT)‐sensitive receptor that is coupled to adenylate cyclase. A structure‐activity study of the 5‐HT molecule indicates that the integrity of the ethylamine sidegroup and the presence of a negatively charged moiety at the 5 position (‐OH, ‐OCH3) are essential for activity. A pharmacological profile is presented for this receptor. The receptor differs from any reported mammalian 5‐HT receptor in that none of the mammalian agonists tested were effective. However, the mammalian antogonists for 5‐HT receptors, spiperone, mianserin, and ketanserin as well as the anti‐histaminic cyproheptadine were all effective antagonists in this preparation. Preliminary analysis of antagonism, particularly by spiperone, shows that these antagonists are probably acting non‐competitively.On the basis of the pharmacological data, and comparisons with other insect systems, the 5‐HT receptor present in the cricket mandibular muscles has been tentatively c

ISSN:0739-4462    

DOI:10.1002/arch.940160302

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

年代:1991

数据来源: WILEY

摘要:

AbstractComparison of the presence and quantities of cuticular hydrocarbons has been used successfully for identifying sibling species and races of several groups of insects. This approach has been extended to four species of moths previously regarded as belonging to the same genus,Heliothis.Gas chromatography was used to quantify the numerous high‐molecular weight alkanes found on the cuticle of two pairs of closely related species:Helicoverpa zeaandHelicoverpa armigera, andHeliothis virescensandHeliothis subflexa.Both sexes ofH. zeaandH. armigeracontained different quantities of several alkanes that could be used for unambiguous identification. Similar comparisons ofH. subflexaandH. virescensshowed four peak ratios that were different for each species. Sexual dimorphism was minor inH. subflexaandH. virescen

ISSN:0739-4462    

DOI:10.1002/arch.940160303

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe objective of this study was to partially characterize and follow the temporal expression of the enzyme ornithine decarboxylase (ODC) throughout embryonic and early larval development ofMusca domestica.Enzymatically active ODC was shown to be present at detectable levels in the embryos only during the latter stages of embryogenesis. This temporally expressed enzyme displayed maximum activity at the time of hatching, and the activity rapidly declined in the newly hatched larvae. The half‐life of ODC activity in extracts at the time of hatching and 30 min after hatching was 57 min and 12 min, respectively. The subunit molecular weight of the embryonic ODC was determined to be 46,000, and the apparent native molecular weight was determined to be 276,000. The concentrations of the polyamines putrescine, spermidine, and spermine also were determined throughout embryogenesis. Spermidine was found to be present in the embryos at about 10‐fold higher concentrations than spermine and at about 100‐fold higher concentrations than putrescine. These polyamines did not undergo major changes in concentration throughout development of the em

ISSN:0739-4462    

DOI:10.1002/arch.940160304

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

年代:1991

数据来源: WILEY

摘要:

AbstractTrnsient expression of a heat‐shock protein‐chloramphenicol acteyltrans‐Perase (hsp‐CAT) recombinant plasmid was used to define the parameters that influence transfection of cultured mosquito cells using DNA‐calcium phosphate coprecipitates. The efficiency of the calcium phosphate procedure was strongly influenced by the growth state of recipient cells, and by the temperature at which the coprecipitate was prepared. Under optimal conditions, which included formation of the DNA‐calcium phosphate coprecipitate at 50°C, transfection frequencies were up to tenfold higher than those obtained using the previously described polybre

ISSN:0739-4462    

DOI:10.1002/arch.940160305

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

年代:1991

数据来源: WILEY

摘要:

AbstractProteinases and peptidases from the intestinal tract of fifth‐instar larvae ofHeliothis ( = Helicoverpa) zea(Boddie) (Lepidoptera:Noctuidae) were characterized based on their substrate specificity, tissue of origin, and pH optimum. Activity corresponding to trypsin, chymotrypsin, carboxypeptidases A and B, and leucine aminopeptidase was detected in regurgitated fluids, midgut contents, and midgut wall. High levels of proteinase activity were detected in whole midgut homogenates, with much lower levels being observed in foregut and salivary gland homogenates. In addition, enzyme levels were determined from midgut lumen contents, midgut wall homogenates, and regurgitated fluids. Proteinase activites were highest in the regurgitated fluids and midgut lumen contents, with the exception of leucine aminopeptidase activity, which was found primarily in the midgut wall. Larvae fed their natural diet of soybean leaves had digestive proteinase levels that were similar to those of larvae fed artificial diet. No major differences in midgut proteinase activity were detected between larvae reared under axenic or xenic conditions, indication that the larvae are capable of digesting proteins in the absence of gut microorganisms. The effect of pH on the activity of each proteinase was studied. The pH optima for the major proteinases were determined to be pH 8.0‐8.5 for trypsin, when tosyl‐L‐arginine methyl ester was used as the substrate; and pH 7.5‐8.0 for chymotrypsin, when benzoyl‐L‐tyrosine ethyl ester was used as

ISSN:0739-4462    

DOI:10.1002/arch.940160306

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

年代:1991

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940160307

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

年代:1991

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940160308

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

年代:1991

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940160309

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

年代:1991

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940160301

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

年代:1991

数据来源: WILEY