ISSN:0739-4462    

DOI:10.1002/arch.940250402

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

年代:1994

数据来源: WILEY

摘要:

AbstractTwo 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. InB. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesi

ISSN:0739-4462    

DOI:10.1002/arch.940250403

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

年代:1994

数据来源: WILEY

摘要:

AbstractSex pheromone titers in females of two tortricid moths,Epiphyas postvittanaandPlanotortrix 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 femaleE. postvittanaandP. octodoes not appear to contain a factor that stimulates pheromone production. After mating, femaleE. postvittanapermanently shut down pheromone production. In contrast, pheromone titer in matedP. octofemales 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 matedE. postvittanafemales 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 matedP. octofemales. 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 femaleE. postvittanato 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 olderE. postvittanafemales 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‐Lis

ISSN:0739-4462    

DOI:10.1002/arch.940250404

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe direct neurohormonal control of pheromone biosynthesis by pheromone biosynthesis activating neuropeptide (PBAN) was demonstrated inHelicoverpa (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 ino

ISSN:0739-4462    

DOI:10.1002/arch.940250405

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

年代:1994

数据来源: WILEY

摘要:

AbstractPheromone 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 inHeliothis virescensthat 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‐L

ISSN:0739-4462    

DOI:10.1002/arch.940250406

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

年代:1994

数据来源: WILEY

摘要:

AbstractMating in most species of insects leads to a transient or permanent loss in sexual receptivity of the females. Among moths, this loss of receptivity is often accompanied with a loss of the sex pheromone in the absence of calling, which also could be temporary or permanent. Most of the earlier work on changes in reproductive behavior after mating was done with Diptera in which sperm and/or male accessory gland secretions were shown to be responsible for termination of receptivity. In the corn earworm moth,Helicoverpa zea, mated females become depleted of pheromone and become nonreceptive to further mating attempts, but only for the remainder of the night of mating. A pheromonostatic peptide isolated from the accessory glands of males may be responsible for the depletion of pheromone, while the termination of receptivity is independently controlled. In the gypsy moth,Lymantria dispar, the changes in behavior following mating are permanent. In this species, the switch from virgin to mated behavior involves three steps: a physical stimulation associated with mating, transfer of viable sperm to the spermatheca, and commencement of oviposition. Signals generated by these factors operate through neural pathways and, unlike inH. zea, accessory gland factors seem not to be involved. © 1994 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of Ameri

ISSN:0739-4462    

DOI:10.1002/arch.940250407

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

年代:1994

数据来源: WILEY

摘要:

AbstractRecently, much effort has been devoted to the elucidation of the neuro‐endocrine mechanisms regulating the biosynthesis and emission of sex pheromones in the Lepidoptera. The available data indicate that the hormonal mechanisms involved vary considerably among species. For example, compelling evidence that juvenile hormones (JH) play a role in the control of sex pheromone production has been presented only for the armyworm moth,Pseudaletia unipuncta. In this species, females that are allatectomized at emergence neither produce nor release pheromone, but both activities are restored following replacement therapy with synthetic JH. However, injection of synthetic JH into neck‐ligated females does not induce pheromone biosynthesis, whereas treatment with either a brain homogenate or synthetic PBAN results in a rise in the pheromone titer. These results indicate that the role played by JH is an indirect one and that the tropic factor is a PBAN‐like substance.Studies on in vitro JH biosynthesis by isolated corpora allata ofP. unipunctahave shown that the low JH output observed early in the life of adult females coincides with the absence of both calling behavior and pheromone production. The subsequent increase in the rates of JH biosynthesis correlates with the onset of pheromone production and release. We have therefore proposed that JH titers must pass a threshold level before the circadian release of PBAN and calling behavior can begin. Furthermore, recent experiments suggest that the continuous presence of JH is necessary for calling behavior to be maintained once initiated. Lastly, we present data suggesting a role for JH or JH acids in the receptivity ofP. unipunctamales to the female sex pheromone. © 1994 Wiley‐L

ISSN:0739-4462    

DOI:10.1002/arch.940250408

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

年代:1994

数据来源: WILEY

摘要:

AbstractPheromone production and/or release by beetles is coordinated with a variety of behavioral, physiological, and environmental factors. To data, two basic mechanisms for the regulation of pheromone biosynthesis in beetles have been proposed. Pheromone biosynthesis may simply be dependent on the availability of biosynthetic precursors. Alternatively, certain stimuli or events may trigger pheromone biosynthesis via juvenile hormone (JH) action. JH may either act directly at the site of pheromone biosynthesis to enhance pheromone production or may act indirectly, through a brain hormone (which might be related to the pheromone biosynthesis activating neuropeptide) or through effects on antennal sensory response. Knowledge of the regulation of the initiation and termination of pheromone biosynthesis is reviewed. Mechanisms by which pheromone stereochemistry is controlled are also discussed. This is an important aspect of pheromone production in Coleoptera, since slight changes in the stereochemistry can completely alter the activity of the molecule. © 1994 Wiley‐Liss, I

ISSN:0739-4462    

DOI:10.1002/arch.940250409

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe relationships between female attractiveness, cuticular hydrocarbons, and levels of juvenile hormone and ecdysteroids were studied inCalliphora vomitoria. The experiments were conducted at 48 and 72 h post‐emergence, according to attractiveness appearance and increase. The 48‐h‐old allatectomized females were less attractive than the control females, whereas no changes occurred either in cuticular hydrocarbons total mass production or in the different hydrocarbon families. However, the 72‐h‐old allatectomized females were more attractive than the control females, and, in relative proportions, allatectomy led to an increase in monomethylalkanes and a decrease in n‐alkanes.Only at 48 h were the ovariectomized females less attractive than the control females and did ovariectomy increase the relative proportions of monomethylalkanes. At 72 h, ovariectomy did not influence female attractiveness, but it decreased the total cuticular hydrocarbon production. Allatectomy and ovariectomy significantly decreased ecdysteroids levels at 48 and 72 h. Ovariectomy did not affect juvenile hormone production.These results suggest that attractiveness and cuticular hydrocarbon synthesis could be under the direct control of ecdysteroids and the indirect influence of juvenile hormone. © 1994 Wil

ISSN:0739-4462    

DOI:10.1002/arch.940250410

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

年代:1994

数据来源: WILEY

摘要:

AbstractDe novo synthesis of contact female sex pheromone and hydrocarbons inBlattella germanicawas examined using short in vivo incubations. Accumulation of pheromone on the epicuticular surface and the internal pheromone titer were related to age‐specific changes in hydrocarbon synthesis and accumulation in normal and allatectomized females. The incorporation of radiolabel from [1‐14C]propionate into the cuticular methyl ketone pheromone fraction was positively related to corpora allata activity during two gonotrophic cycles. During peak pheromone production the total internal lipid fraction contained greater titers of pheromone than the cuticular surface, and it too exhibited a cycle internally, preceding the rise in external pheromone. This suggests that synthesis and accumulation of pheromone internally are followed by transport of pheromone to the epicuticular surface where it accumulates. Radiolabel was incorporated efficiently into both cuticular and internal hydrocarbons after the imaginal molt and until the peak of pheromone synthesis, but it declined to lower levels before ovulation and throughout pregnancy. The internal hydrocarbon titer decreased 58% after oviposition, suggesting deposition in the egg case. It remained relatively unchanged during pregnancy and increased again during the second gonotrophic cycle. In allatectomized females, hydrocarbon synthesis was reduced relative to control females until oviposition in the latter. However, subsequent rates of hydrocarbon synthesis in allatectomized females (without oothecae) exceeded the rates in sham‐operated females (with oothecae). In the absence of ovarian uptake of hydrocarbons, the internal titer increased without the decline found in control females at oviposition. As internal hydrocarbons increased, so did cuticular hydrocarbons and both internal and cuticular methyl ketone pheromones. These patterns corresponded well with feeding patterns in sham‐operated and allatectomized females, suggesting that pheromone production is normally regulated by stage‐specific feeding‐induced hydrocarbon synthesis (precursor accumulation internally) and juvenile hormoneinduced conversion of hydrocarbon to pheromone. They also suggest that both the cuticle and the ovaries might be target sites for hydrocarbon and possibly methyl ketone deposition. © 1994 Wil

ISSN:0739-4462    

DOI:10.1002/arch.940250411

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

年代:1994

数据来源: WILEY