摘要:

AbstractJuvenile hormone (JH) III esterase and JH III epoxide hydrolase activity was found in the integument, midgut, fat body, and brain during last instar development of the tobacco hornworm,Manduca sexta. JH esterase activity was primarily located in the cytosol in these tissues while the majority of the JH epoxide hydrolase activity was found in the microsomes. A prewandering (on day 3) and postwandering (on day 8) peak in plasma JH III esterase activity occurs in the last instar of gate IM. sexta. The JH esterase activity profile in integument, midgut, fat body, and brain followed a similar pattern to that of the plasma. The only exception to this was the absence of the postwandering, prepupal (on day 8) JH esterase peak in the fat body. The topical application of the juvenoid, (RS)‐methoprene, failed to induce fat body JH esterase activity but increased activity in the plasma, integument, midgut, and brain inM. sextaprepupae. These results indicate that the source of plasma JH esterase activity is not always the fat body as previously hypothesized. The developmental profile of tissue JH epoxide hydrolase activity was also similar to that of JH esterase suggesting that both enzymes may be regulated partly by the same factors and that JH epoxide hydrolase may also have an important, previously unrecognized functional role in JH regulation and insect metamorphosis. Multiple isoelectric forms of tissue‐specific JH esterases and JH epoxide hydrolases were found in integument, midgut, fat body, and brain. The JH esterases in these tissues had isoelectric points more acidic than that for plasma. Tissue α‐naphthyl acetate esterase, developmental profiles, and inhibitor sensitivity to 3‐(octylthio)‐1,1,1‐trifluoropropan‐2‐one differed significantly from that for JH esterase, suggesting that they represent different enzymes. ©199

ISSN:0739-4462    

DOI:10.1002/arch.940200202

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe post‐diapause development (PDD) time for univoltine European corn borers (ECB) under diapause breaking conditions averages approximately 44 days, whereas the PDD time for bivoltine ECB under the same conditions is approximately 15 days. This difference is the principal component of the life cycle that determines the number of generations possible in a summer. Previous workers have demonstrated some genetic control of differences in voltinism among populations, including apparent control by sex‐linked (Z‐linked) genes.In the present study allozymes of the enzyme, triose phosphate isomerase (TPI), were used as markers of the Z chromosomes in crosses of a bivoltine colony (Tpi‐1) and a univoltine colony (Tpi‐2). The F1resulting from a cross of univoltine females (Z2W) and bivoltine males (Z1Z1) consisted of hemizygous Tpi‐1 females (Z1W) with a mean PDD time of 19 days and heterozygous Tpi‐1/Tpi‐2 males (Z1Z2) with a mean PDD time of 34 days. The F2progeny consisted of Tpi‐1 females (Z1W) (mean PDD time = 15 days), Tpi‐2 females (Z2W) (mean PDD time = 40 days), homozygous Tpi‐1 males (Z1Z1) (mean PDD time = 16 days), and heterozygous Tpi‐1/Tpi‐2 males (Z1Z2) (mean PDD time = 25 days). The close correlation of TPI phenotypes and PDD times in these crosses, along with similar results for the maternal and paternal backcrosses of the F1individuals, indicates that the PDD time is principally controlled by genes on the Z chromosome and that heterozygous males exhibit incomplete or partial dominance of these gene

ISSN:0739-4462    

DOI:10.1002/arch.940200203

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe protein composition of larval and adult hemolymph from the Colorado potato beetle,Leptinotarsa decemlineata, was investigated and some abundant, high molecular weight proteins were identified and characterized. Diapause protein 1, which occurs in the hemolymph of last instar larvae and short‐day adults, appeared to be a storage protein. This protein dissociated into two bands due to the high pH used in nondenaturing gels. Its quaternary structure was established by chemical crosslinking. It appeared to be a hexamer. Diapause protein 1 is composed of ≈82,000 subunits. The amino acid composition and N‐terminal sequence of this protein has been determined. Specific antibodies against diapause protein 1 have been developed. Topical application of 1 μg pyriproxyfen, a juvenile hormone analog, to last instar larvae and short‐day adults suppressed the appearance of this protein in the hemolymph. Pyriproxyfen prematurely induced vitellogenin, when applied to last instar larvae.A larval specific protein was also identified in the hemolymph. Its temporary appearance in the hemolymph of last instar larvae, its subunit composition (Mr≈82,000) and its suppression by pyriproxyfen suggests that this protein is a storage protein as well. © 1992 Wile

ISSN:0739-4462    

DOI:10.1002/arch.940200204

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

年代:1992

数据来源: WILEY

摘要:

AbstractFine details of the infradian O2consumption cycles that characterize pupal diapause in flesh flies have been monitored by a newly designed microrespirographic method coupled with an electronically regulated O2generator. During the 4–5 days between the peaks of elevated O2consumption the diapausing pupae maintained a very low and fairly constant respiratory rate (13 μl O2· g−1· h−1). During the intercalated peaks of increased respiratory metabolism, which lasted an average of 33.6 h at 24–27°C, the average maximum rate of O2consumption was 86.9 μl · g−1· h−1, a value 6.7 times higher than the interpeak values. The respiratory peaks started abruptly in some cases, while the decline was consistently gradual. During the periods between the peaks there were no discontinuous bursts of CO2release, a feature common to diapause in many other insects. Diapause was characteristically terminated during a peak of the O2consumption cycle. At diapause termination O2consumption remained at the maximum values of the peak for many hours and then gradually increased to levels characteristic of nondiapause development. © 1

ISSN:0739-4462    

DOI:10.1002/arch.940200205

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

年代:1992

数据来源: WILEY

摘要:

AbstractAllatotropin (AT) is a 13 amino acid neuropeptide isolated from the tobacco hornworm,Manduca sexta, which stimulates the biosynthesis of juvenile hormone (JH) in adult females of this insect. In this paper we report that AT stimulates inositol phosphate formation in both female and male corpora allata (CA) of adultManduca sexta. Furthermore, thapsigargin, a potent Ca2+‐ATPase inhibitor, staurosporine, a potent inhibitor of protein kinases A and C, and 2,5‐di‐(tert‐butyl)‐1,4‐hydroquinone (DBHQ), a potent inhibitor of liver microsomal ATP‐dependent Ca2+sequestration, all stimulate JH biosynthesis without changing the basal level of inositol phosphates. These data suggest that AT activates an inositol 1,4,5‐trisphosphate (IP3) pathway. Furthermore, increases in the free intracellular Ca2+concentration in the CA stimulate JH biosynthesis. © 1992

ISSN:0739-4462    

DOI:10.1002/arch.940200206

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

年代:1992

数据来源: WILEY

摘要:

AbstractPolyclonal antibodies were produced against trypsin‐like enzyme TLE‐2, one of two trypsins isolated from the midgut cecae of the locustLocusta migratoria. Using those antibodies a heterologous RIA was developed. The specificity of the antibodies was demonstrated by immunoblot technique and cross‐reactivity experiments. Positive blot reaction with the antiserum was observed with locust trypsins and binding competition was obtained only with the second trypsin from the locust, TLE‐1. Trypsins from bovine and hog as well as trypsins fromTenebrio molitorandTribolium castaneumand locust chymotrypsin did not inhibit TLE‐2 binding to the antiserum even at concentrations 1,000‐fold greater than that of locust TLE‐2. The concentrations of TLE‐2 in cecal fluid, cecal wall, hemolymph, and fat‐body were 2,790, 60.4, 6.4, and 0.7 ng per mg tissue, respectively. © 19

ISSN:0739-4462    

DOI:10.1002/arch.940200207

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

年代:1992

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940200208

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

年代:1992

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940200201

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

年代:1992

数据来源: WILEY