摘要:

AbstractA diapause associated protein (DAP) (Mr103,000) was isolated from the hemolymph and fat body of diapausing fourth instar larvae of the pink bollwormPectinophora gossypiella. The protein has been named Pectinophora diapause protein (PDP). The in vitro translation peptide patterns of total RNA from the fat body of actively feeding fourth instar, wandering, prediapause, early diapause, mid‐diapause, and late diapause larvae in rabbit reticulocyte lysates showed the presence of poly (A)+RNA sequence of PDP. The antigen was immuno‐precipitated by polyclonal antiserum. It was concluded that the transcription of the PDP gene in the fat body cells started in the late fourth instar larva and that the expression of this gene was regulated at the level of transcription in the fat body of diapausing larvae. Northern hybridization analysis revealed that wandering fourth instar larvae (diapause individuals) maintain a relatively low level of diapause message (mRNA/2.4 kb) in their fat body cells which may be necessary for the induction of diapause. © 1993 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/arch.940230103

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

年代:1993

数据来源: WILEY

摘要:

AbstractExposure of larval and pupal testes ofLymantria disparto diacyl glycerol mimics, phorbol, 12‐myristate, 13‐acetate, and 11, 12 dibutyryl phorbol ester, induced or augmented synthesis of immunodetectable ecdysteroids. The non‐esterified analog, 4α‐phorbol, had little effect. H‐7, a protein kinase C inhibitor, inhibited ecdysteroid synthesis. When testis ecdysiotropin and phorbol esters were administered together at the maximum effective dose of each, steroidogenesis was further enhanced. Therefore, diacyl glycerol may be a second messenger for testis ecdysiotropin in testes. In addition, testis ecdysiotropin induced a rapid rise and fall in cAMP titers in both larval and pupal testes. The cyclic AMP analog, dibutyryl cyclic AMP, induced ecdysteroid synthesis in larval testes, but had little steroidogenic effect in pupal testis sheaths. However, dibutyryl cyclic AMP inhibited the steroidogenic effect of testis ecdysiotropin in larval as well as pupal testes. Cyclic AMP may act to modulate the effects of testis ecdysiotropin in inducing ecdysteroid synthesis by testes ofL. dispar. © 1993 Wile

ISSN:0739-4462    

DOI:10.1002/arch.940230104

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe chemical nature of the major ecdysteroid from pupae of the leaf‐cutting antAcromyrmex octospinosushas been reinvestigated. On the basis of reversed phase high performance liquid chromatography and mass spectrometry, this compound was previously identified as makisterone A [Maurer et al., Arch Insect Biochem Physiol16, 1 (1991)] but a more careful examination has led to the conclusion that it is in fact 24‐epi‐makisterone A. This finding stresses the limits of criteria used for the identification of ecdysteroids and the possible need for reexamination of makisterone A identification in some other species feeding on a 24β‐methyl sterol source. © 1993 Wiley

ISSN:0739-4462    

DOI:10.1002/arch.940230105

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

年代:1993

数据来源: WILEY

摘要:

AbstractAnalysis of lipids in salivary glands of the lone star tick,Amblyomma americanum, demonstrated that arachidonic acid (20:4, n‐6) comprises 8% of all fatty acids identified by gas chromatography. The occurrence of arachidonic acid and other C20polyunsaturated fatty acids in tick salivary glands was confirmed by gas chromatography‐mass spectrometry. Arachidonate is located entirely in the phospholipid fraction and is associated exclusively with phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Salivary glands stored and frozen for several months had a similar lipid composition as freshly dissected salivary glands, with the exception of a small amount of free arachidonic acid and an increase in lysophosphatidylcholine. Incubation of salivary gland homogenates with snake venom phospholipase A2showed that most saturated fatty acids are esterified in the sn‐1 position of PC and PE, with the unsaturated fatty acids in the sn‐2 position. Approximately 75% of arachidonic acid is in the sn‐2 position of PC and PE, adding support to the hypothesis that arachidonic acid is released into the cytoplasm after activation of a phospholipase A2for subsequent metabolism to prostaglandins and/or other eicosanoids. © 1993 Wiley

ISSN:0739-4462    

DOI:10.1002/arch.940230106

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

年代:1993

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940230102

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

年代:1993

数据来源: WILEY