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1.
《Journal of Asia》2002,5(1):43-48
This study was undertaken to clarify the suppression phenomenon of sex pheromone production after mating and its relationship to the physiological mechanism in adult females of Helicoverpa assulta, and determine the mating factor from males causing depletion of sex pheromonc production. Sex pheromone production of H. assulta females was mostly terminated in 3 hours after mating. Mated females maintained with a low titer of sex pheromone until 3 days when it started to increase again, which showed a characteristic of species mating more than once. The mated female again produced pheromone upon injection of pheromone biosynthesis activating neuropeptide (PBAN) or extracts of brain-suboesophageal ganglion complexes (Br-Sg) of mated female, which were shown similar pheromonotropic activities as compared with virgin females. These results indicated that the mating did not inhibit the receptivity of pheromone gland itself and PBAN biosynthesis in suboesophageal ganglion of the mated females. And it seems to support that the depletion of sex pheromone production is responsible for blocking of PBAN release from head. To investigate the mating factor from adult males, when extracts of reproductive organs of male were injected into hemocoel of virgin females evoking depletion of sex pheromone production as shown in mated female. The results suggest that a chemical substance(s) from the male reproductive organs could be responsible for the loss of sex pheromone biosynthesis in H. assulta.  相似文献   

2.
Mating results in a strong suppression of sex pheromone (bombykol) production in the female silkworm moth, Bombyx mori. The mechanical stimulation from the insertion of a penis, inflation of the bursa copulatrix (BC), or copulation with the sterile male whose penis was removed in order to prevent ejaculation (pr-male) induced only a partial decline in bombykol production. Artificial insemination stimulates oviposition of fertilized eggs as does normal mating. However, bombykol production did not decline in artificially inseminated females. When females were artificially inseminated before or after mating with pr-males, some females had a small amount of bombykol, similar to females mated with normal males, while other females had a large amount of bombykol similar to virgin females. The former usually laid fertilized eggs, while the latter laid only unfertilized eggs though semen filled their spermatophores and spermathecae. The mechanical stimulation caused by mating with a pr-male could be replaced by covering the abdominal tip with melted paraffin. Neither implantation of the BC obtained from mated females, nor injection of the spermatophore extract, into a female mated with a pr-male could inactivate bombykol production. Injection of hemolymph from a mated female into a virgin also failed to affect bombykol production These results indicate that a combination of both the tactile stimulation of the abdominal tip and the arrival of fertile spermatozoa in the vestibulum trigger a neural inactivation mechanism of bombykol production after mating.  相似文献   

3.
Sex pheromone titers in females of two tortricid moths, Epiphyas postvittana and Planotortrix octo, did not significantly vary between the scotophase and photophase. Pheromone production in these two species is controlled by a factor located in the head of the respective females, probably the pheromone biosynthesis-activating neuropeptide (PBAN). Unlike that reported for the related tortricid, Argyrotaenia velutinana, the bursa copulatrix in female E. postvittana and P. octo does not appear to contain a factor that stimulates pheromone production. After mating, female E. postvittana permanently shut down pheromone production. In contrast, pheromone titer in mated P. octo females is reduced to a level approximately half that of similar-age virgins. While the abdominal nervous system is involved in the inactivation of pheromone production in mated E. postvittana females and probably acts to stop release of PBAN from the corpora cardiaca, the abdominal nervous system is not involved in effecting the decreased pheromone titers of mated P. octo females. It is possible that in the latter species, a humoral factor(s) is responsible for effecting the decreased pheromone titers, possibly through affecting the release of PBAN from the corpora cardiaca. Bioassaying head extracts allowed changes in PBAN titer in female E. postvittana to be inferred. PBAN titers remain roughly constant in virgins but increase after mating. This suggests that PBAN is biosynthesized throughout the life of an adult virgin female at approximately the same rate as it is released. Furthermore, it appears that the decline in pheromone titer observed in older E. postvittana females is probably due to a decline in competency of the gland to produce pheromone rather than to a decrease in PBAN titer in older females. © 1994 Wiley-Liss, Inc.  相似文献   

4.
Mating in the redbanded leafroller moth, Argyrotaenia velutinana, causes a permanent decline in pheromone titers. Three hours following the termination of mating, phermone titers were significantly decreased from premating levels, and titers remained low for at least four days after mating. Pheromone titers were similar in females that had been decapitated or mated for twenty-four hours. In the redbanded leafroller moth, two peptides control pheromone production. The pheromone biosynthesis activating neuropeptide is produced in the brain and the pheromonotropic bursa peptide is produced in the corpus bursae. Both peptides stimulated pheromone biosynthesis in mated females and extracts prepared from brains and bursae of mated females contained pheromonotropic activity. However, severing the ventral nerve cord before mating prevented the decline in pheromone titer that occurred in mated females. Hemolymph collected during scotophase from mated females did not have pheromonotropic activity, whereas hemolymph collected during scotophase from virgin females contained activity. These results indicate that mating produces a signal sent by the ventral nerve cord to the brain to stop the release of pheromone biosynthesis activating neuropeptide. © 1993 Wiley-Liss, Inc.  相似文献   

5.
Pheromone biosynthesis in many species of moths requires a pheromonotropic neurosecretion, the pheromone biosynthesis activating neuropeptide (PBAN), from the brain-subesophageal ganglion-corpora cardiaca complex. Some investigators suggest that PBAN is released into the hemolymph and acts directly on sex pheromone glands (SPG) via a Ca++/calmodulin-dependent adenylate cyclase. Others suggest, however, that PBAN acts via octopamine that is released by nerves from the terminal abdominal ganglion innervating the SPG. These findings suggest that there are controversies on the mode of action of PBAN and other pheromonotropic factors, sometimes even within the same species. Mating in many insects results in temporary or permanent suppression of pheromone production and/or receptivity. Such a suppression may result from physical blockage of the gonopore or deposition of pheromonostatic factor(s) by the male during copulation that result in suppressed pheromone production and/or receptivity in females either directly or by a primer effect. In several species of insects, including moths, a pheromonostatic factor is transferred in the seminal fluid of males. Similar to the controversies associated with the pheromonotropic activity of PBAN, sometimes even within the same species, there appear to be controversies in pheromonostasis in heliothines as well. This paper reviews these conflicting findings and presents some data on pheromonostatic and pheromonotropic activity in Heliothis virescens that support and conflict with current information, raising further questions. Answers to some of the questions are partly available; however, they remain to be answered unequivocally. © 1994 Wiley-Liss, Inc.  相似文献   

6.
Nine-day-old decapitated females injected with different doses of Hez-PBAN produced significantly less pheromone than 1-day-old individuals, suggesting that the age-related decline in the pheromone titre of Choristoneura fumiferana and C. rosaceana virgin females was primarily the result of a reduced ability of the glands to produce pheromone. In C. fumiferana, lower pheromonotropic activity of the Br-SEG may also contribute to the pheromone decline with age but not in C. rosaceana, as the pheromonotropic activity of the Br-SEG remained constant throughout the females' life. In both Choristoneura species, mating also suppressed pheromone production (pheromonostasis) after 24 h. The Br-SEG of mated females contained PBAN but there was no indication that its concentration changed with time post-mating since Br-SEG homogenates obtained from different-aged mated females showed the same level of pheromonotropic activity in both Choristoneura species. However, as observed in virgins, pheromone glands of older mated females were less sensitive to PBAN than those of younger ones. This suggests that the probability of Choristoneura females to attract a second mate may decrease with an increase in the refractory period following the first mating.  相似文献   

7.
Pheromone biosynthesis in the redbanded leafroller moth, Argyrotaenia velutinana, was stimulated by homogenates of the bursa copulatrix. Although pheromonotropic activity was also extractable from the ovary, the activity of pheromone biosynthesis activating neuropeptide (PBAN) or bursa extracts was not impaired in isolated abdomens by removal of the ovary. Response to the bursa extracts was dependent on the dose administered and the time of incubation. Amounts of pheromone present in adult females of different ages appeared to be correlated with the extractable amount of pheromonotropic activity from their bursa copulatrix. Decapitation did not result in the suppression of burse factor production. Homogenates of the bursa elicited similar effects in both isolated gland and isolated abdomen incubations, but the brain neuropeptide, PBAN, was less active in the former than in the latter. Bursa extracts stimulated pheromone production in isolated abdomen incubations deprived of the bursa copulatrix, but PBAN did not. Loss of activity of bursa homogenates after treatment with either pronase E or carboxypeptidase Y indicated that the pheromonotropic factor is a proteinaceous substance. The mechanism through which pheromone production is regulated in redbanded leafroller moths is discussed. © 1992 Wiley-Liss, Inc.  相似文献   

8.
In the spruce budworm, Choristoneura fumiferana, and the obliquebanded leafroller, C. rosaceana, mating significantly depressed pheromone production after 24 h. On subsequent days, the pheromone titre increased slightly in C. fumiferana, but not in C. rosaceana. No pheromonostatic activity was associated with male accessory sex gland (ASG) extracts, 20-hydroxy-ecdysone or hemolymph taken from mated females. However, pheromone production in mated females was not suppressed when the ventral nerve cord (VNC) was transected prior to mating, indicating that an intact VNC is required to permanently switch off pheromone production after mating. As suggested for other moth species, the presence of sperm in the spermatheca probably triggers the release of a signal, via the VNC, to inhibit pheromone production. The fact that in both species the brain-suboesophageal ganglion (Br-SEG) of mated females contains pheromonotropic activity and that their pheromone glands may be stimulated by the synthetic pheromone-biosynthesis-activating-neuropeptide (PBAN) or a brain extract supports the hypothesis that the neural signal prevents the release of PBAN into the hemolymph rather than inhibiting its biosynthesis. Therefore, we speculate that following the depletion of sperm in the spermatheca, the neural signal declines and is less effective in preventing the release of PBAN, thereby stimulating the resumption of pheromone production, as seen in mated C. fumiferana females. In a previous study, mating was shown to induce a significant rise in the juvenile hormone (JH) titre of both Choristoneura female moths, suggesting that post-mating pheromone inhibition may be under hormonal regulation. However, following topical applications or injections of the juvenile hormone analogue (JHA) and JH II into virgins, the pheromone only declined significantly 48 h after treatment in C. rosaceana. This suggests that the significant rise in the hemolymph JH titre after mating in C. rosaceana females plays a role in keeping the pheromone titre consistently low throughout their reproductive life. These findings will be discussed in relation to the different life histories of the two Choristoneura species.  相似文献   

9.
The sequence of an 18-amino acid residue peptide was deduced from the gene encoding PBAN and other peptides with common C-termini in Helicoverpa zea. The peptide caused melanization in larvae and pheromone production in females of H. zea, and was designated pheromonotropic melanizing peptide (Hez-PMP). The peptide has a 83% sequence homology with a pheromonotropic peptide isolated from Pseudaletia separata. PMP caused melanization and mortality when injected into larvae just before molting. Whereas intense melanization was caused with a dose of 1,000 pmol, peak mortality occurred at 100 pmol, with 50% of larvae dying within 48 h after injection. Pheromonotropic activity of PMP was dose dependent. Co-injection of Hez-PMP and Hez-PBAN into a female resulted in suppression of the pheromonotropic effect of PBAN. Whole-mount immunocytochemical studies revealed PMP-like immunoreactivity in frontal ganglion, subesophageal, thoracic, and abdominal ganglia as well as the esophageal nerve.  相似文献   

10.
Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN-I and -II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN-I is a carboxyl-terminally amidated 33-residue peptide. Structure-activity relationship studies revealed that 1) its carboxyl-terminal pentapeptide is the smallest size showing activity, 2) the carboxyl-terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN-I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl-terminal hexapeptide showed that modification of the amino-terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl-terminal sequence, -Phe-Xaa-Pro-Arg-Leu-NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross-activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol. © 1994 Wiley-Liss, Inc.  相似文献   

11.
烟夜蛾雄蛾性附腺因子对雌蛾性信 息素合成的抑制作用   总被引:8,自引:0,他引:8  
烟夜蛾Helicoverpa assulta处女蛾在交配后1 h,其性信息素滴度即显著降低,72 h内未见恢复。生测结果表明,烟夜蛾性信息素合成抑制因子主要来源于雄蛾性附腺。不同日龄雄蛾性附腺提取物的抑制活性无显著差异。光暗期对其活性具显著影响,暗期中雄蛾的性附腺物质对雌蛾性信息素合成具有较强抑制作用,而光期中雄蛾的性附腺物质不具抑制活性。在暗期的不同时间处理,对处女蛾性信息素合成的抑制作用无显著差异。雄蛾性附腺提取物对雌蛾性信息素合成的抑制作用与注射剂量有明显的相关性,0.2 ME(雄蛾当量)是产生显著抑制作用的最小剂量。对交配雌蛾注射性信息素生物合成激活神经肽(PBAN)提取物后,其性信息素合成又可恢复,这说明雌蛾交配后,性信息素滴度降低的原因是由于缺少了PBAN的调控。  相似文献   

12.
The present study investigates the effects of age and mating status on the circadian variations of gland sex pheromone titre in female Spodoptera litura Fabricius. Similar to other nocturnal moths, S. litura females exhibit circadian variations of gland sex pheromone contents, with higher levels during scotophase and lower levels during photophase. The sex pheromone titre in the glands peaks during the first scotophase after eclosion and sharply declines afterwards. Higher pheromone contents during scotophase may facilitate female reproductive activities, and the negative relationship between pheromone titre and female calling is likely the result of pheromone release during female calling. Interestingly, the present study demonstrates that mated S. litura females have significantly higher sex pheromone titre in their pheromone glands (PGs) than virgin females. This finding contrasts with all previous studies of other insect species, in which mating generally reduces the sex pheromone titre in female PGs. In S. litura, mating and male accessory gland fluids can suppress female calling behaviours and re‐matings. These results suggest that the suppression of female calling behaviours by mating and male accessory gland fluids may significantly reduce the release of sex pheromones and thus result in higher sex pheromone titre in the PGs of mated females.  相似文献   

13.
Insect males produce accessory gland (MAG) factors that are transferred in the seminal fluid to females during copulation, and elicit changes in the mated female's behavior and physiology. Our previous studies showed that the injection of synthetic Drosophila melanogaster sex-peptide (DrmSP) into virgin females of the moth Helicoverpa armigera causes a significant inhibition of pheromone production. In this and other moth species, pheromone production, correlated with female receptivity, is under neuroendocrine control due to the circadian release of the neuropeptide PBAN. In this study, we show that PBAN, present in the hemolymph during the scotophase in females, is drastically reduced after mating. We also identify 4 DrmSP-like HPLC peaks (Peaks A, S1, S2, and B) in MAGs, with increasing levels of DrmSP immunoreactivity during the scotophase, when compared to their levels observed during the photophase. In H. armigera MAGs, a significant reduction in the pheromonostatic peak (Peak B) was already evident after 15 min of copulation, and depletion of an additional peak (Peak S2) was evident after complete mating. Peak A is also detected in female brains, increasing significantly 1 h after mating, at which time inhibition of pheromone biosynthesis also occurs. However, changes corresponding to the other MAG peaks were not detected in mated female tissues.  相似文献   

14.
In most female moths, pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production by stimulating an influx of extracellular Ca(2+). Little is known about the plasma membrane channel or how the PBAN stimulus is communicated to the channel. Fluorescent Ca(2+) imaging techniques confirmed PBAN-induced Ca(2+) influx in the silkworm, Bombyx mori, and showed that the PBAN response is reduced with repeated stimulation. Compounds known to impact Ca(2+) signaling were examined for their effects on sex pheromone production. These experiments demonstrated that the PBAN signal is likely mediated by a store-operated channel (SOC). SOC blockers, SKF-96365 and 2-aminoethoxydiphenyl borate, abolished sex pheromone production, as did flufenamic acid, a blocker of transient receptor potential (TRP) channels. Thapsigargin mimicked the pheromonotropic effects of PBAN. Similar results were seen when PBAN-induced lipase activity was assayed. Conversely, 1-oleoyl-2-acetyl-sn-glycerol and arachidonic acid, activators of diacylglycerol-dependent Ca(2+) channels, had no effect on bombykol production.  相似文献   

15.
In a previous study we showed that juvenile hormone (JH) or its analog, fenoxycarb (FX), is involved in the up-regulation of pheromone biosynthesis-activating neuropeptide (PBAN) competence. JH causes induction of binding to a putative PBAN-receptor (PBAN-R) and the subsequent pheromone production by pheromone glands of pharate females. The present study demonstrates that pheromone production by the adult female is age-dependent. The pheromonotropic response increased to reach a maximum at 4 days, after which a decreased response was observed. Binding of the PBAN-R was also age-dependent. Treatment with FX inhibited both binding of PBAN to the PBAN-R and the pheromonotropic response as reflected by the production of the main pheromone component, Z-11-hexadecenal. Thus, in contrast to its up-regulatory role in pharate females, FX treatment of adult females causes down-regulation of both pheromone production and specific binding to the PBAN-R. In addition, behavioural observations showed that calling behaviour, mating success and subsequent egg-fertility are affected by treating females with FX.  相似文献   

16.
The correlation between triacylglycerols containing conjugated diene fatty acyl moieties and pheromone aldehydes in the sex pheromone glands of females of Manduca sexta was investigated. Females decapitated 15 h after adult emergence neither called nor produced pheromone during the natural period of pheromone production on the subsequent two nights. However, these females could be stimulated to produce sex pheromone for prolonged periods by repeated injection of synthetic pheromone biosynthesis activating neuropeptide (PBAN). Gas chromatographic analysis of methanolysis products of lipids extracted from the pheromone glands of decapitated and intact females showed no differences in the amounts of fatty acyl precursors of pheromone. High performance liquid chromatographic analysis of the triacylglycerols containing conjugated diene analogues of the pheromone components (diene TG), obtained 24 and 48 h after decapitation, showed that the total amounts of these components were not affected by decapitation. The amounts of all diene TG peaks declined significantly when decapitated females were stimulated to produce pheromone during a 7 h period by repeated injection of PBAN at 3 h intervals but recovered when pheromone production subsided. These results indicate that PBAN induces liberation of pheromone precursors from the triacylglycerols during pheromone biosynthesis but does not induce replenishment of this storage pool. © 1996 Wiley-Liss, Inc.
  • 1 This article is a US Government work and, as such, is in the public domain in the United States of America
  •   相似文献   

    17.
    The adrenergic agonists octopamine, tyramine and clonidine inhibited the normal pheromonotropic action due to PBAN (pheromone biosynthesis activating neuropeptide) in incubations of intersegmental tissues that are situated between the 8th and 9th abdominal segments of the moth ovipositor tip. This inhibition was reversed in the presence of the adrenergic antagonists phentolamine, yohimbine and chlorpromazine. Incubations of 8th segments alone, which do not produce pheromone, resulted in elevated levels of intracellular cAMP in the presence of octopamine. The physiological significance of this phenomenon is unclear. However, clonidine (an alpha(2) selective agonist) did not duplicate octopamine stimulation of intracellular cAMP in 8th segment cultures. In intersegmental membrane cultures clonidine successfully duplicated the octopamine inhibition of both pheromone and intracellular cAMP production. The physiological significance of octopaminergic receptors mediating the inhibitory response of intersegments was investigated by experiments in vivo. When PBAN was injected into photophase females the normal pheromonotropic activity due to the injected PBAN dropped after 2h. In the presence of clonidine, normal peak stimulatory levels were never attained and a faster decline was observed. Clonidine also inhibited the pheromonotropic response of 24h-decapitated females to PBAN. Adrenergic antagonists successfully reversed the inhibitory effect of clonidine in decapitated females, but did not reverse the effect of clonidine in photophase females. In addition, when clonidine was injected into female moths during the scotophase normal peak pheromone titers were reduced although no effect on calling behavior was observed. Copyright 1997 Elsevier Science Ltd. All rights reserved  相似文献   

    18.
    In many moth species regulation of pheromone production has been attributed to the timely release of a pheromone biosynthesis activating neuropeptide (PBAN). The gene encoding PBAN has been sequenced in two moth species. Immunochemical studies as well asin situ hybridization and Northern analysis of PBAN encoding mRNA have localized the neuroendocrine cells responsible for the production of PBAN and have traced the neuronal network of PBAN immunoreactivity. Release into the bloodstream has been demonstrated, the target tissue delineated, and the signal transduction pathway and its modulation analyzed. This paper reviews the current status of research concerning the neuroendocrine control of pheromone production in Lepidopterans and presents some recent developments concerning the receptors involved in the pheromonotropic activity. In this study, we report on the use of a biologically active photoaffinity-biotin-labeled derivative of PBAN N-[N-(4-azido-tetrafluorobenzoyl-biocytinyloxyl-succinimide) and show the presence of a protein (estimated molecular weight of 50 kDa) which specifically binds to PBAN in membrane preparations of pheromone glands. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No.2279-E, 1997 series  相似文献   

    19.
    20.
    The direct neurohormonal control of pheromone biosynthesis by pheromone biosynthesis activating neuropeptide (PBAN) was demonstrated in Helicoverpa (Heliothis) spp. using pheromone gland cultures in vitro. Pheromone gland activation involved the de novo production of the main pheromone component (Z)-11-hexadecenal as revealed by radio-TLC, radio-HPLC, and radio-GC. Activation was found to be a specific response attributed to pheromone gland cultures alone. Specificity of pheromonotropic activation was demonstrated to be limited to nervous tissue extracts. A sensitive and specific radioimmunoassay was developed using [3H]-PBAN, and the spatial and temporal distribution of PBAN-immunore-activity was studied. PBAN-immunoreactivity in brain complexes was found throughout the photoperiod and in all ages. From the distribution of PBAN-immunoreactivity it appears that PBAN release is affected by photoperiod. Pheromone gland cultures were found to be competent to pheromone production irrespective of age and photoperiod. Therefore, the neuroendocrine control of pheromone production operates at the level of neuropeptide synthesis and/or release and not at the level of the target tissue itself. The involvement of cyclic-AMP as a second messenger system was demonstrated. Brain extracts and PBAN were shown to stimulate dose- and time-dependent changes in intracellular cyclic-AMP levels. The role of cyclic-AMP in this mechanism was further verified by the ability of cyclic-AMP mimetics to mimic the pheromonotropic effect of brain extracts and PBAN. However, dose-response studies using PBAN and a hexapeptide C-terminal fragment of PBAN suggested that PBAN induces a two mechanism response, one occurring at low PBAN concentrations (high affinity receptor) and another at higher PBAN concentrations (low affinity receptor). Further evidence indicating a dual receptor system was obtained with the observation that the active phorbol ester (phorbol-12-myristate 13-acetate), the diacyl-glycerol analog (1,2-dioleolyl-sn-glycerol), and the intracellular calcium ionophore (ionomycin) mimicked the physiological action of PBAN and that lithium chloride had a pheromonostatic effect. The results indicate that pheromone glands also possess receptors that are linked to inositol phosphate hydolysis. © 1994 Wiley-Liss, Inc.  相似文献   

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