Comparison of ecdysteroid concentration in different morphs of aphids

Polgár, László; Darvas, B.; Völkl, Wolfgang; Porcheron, P.; Székacs, András; Szelinger, S.

doi:10.1016/s0742-8413(96)00104-1

Cited by 5 publications

(8 citation statements)

References 25 publications

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“…In contrast, polyvoltine parasitoid species have species-specific regulatory systems and seem to be able to respond to a variety of cyclical changing environmental abiotic (e.g. However, a number of aphid parasitoids also seem capable of responding to differences in the host aphid, which may result from differences in their endocrine activity (Hardie, 1981(Hardie, , 1984Hardie & Lees, 1985;Polgár et al, 1996). In these species, the sensitive stages may respond to specific cues, which may vary between parasitoid species, within a parasitoid species and between different host species Christiansen-Weniger & Hardie, 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Here ecdysterone application to larvae terminated diapause, but no differences were found in the JH titres of diapausing and non-diapausing larvae (De Loof et al, 1979). It has been demonstrated that fundatrices and oviparae of a number of aphid species seem to possess higher titres of ecdysteroids than other morphs (apterous virginoparae, alate virginoparae) of the same species (Polgár et al, 1996). A diapause-like extended development was also induced with RH-5849 in A. matricariae when it was applied to aphids containing 'middle-stage' parasitoid larvae (Polgár & Darvas, 1991).…”

Section: Hormonal Control Of Diapause Inductionmentioning

confidence: 92%

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Diapause induction in aphid parasitoids

Polgár

Hardie

2000

Entomologia Exp Applicata

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Diapause is one of the adaptations that insects have evolved for the synchronisation of their life cycle with seasonal climatic changes and resources. In aphid parasitoids, univoltine species have an obligatory, genetically determined diapause. Polyvoltine species, on the other hand, use a variety of abiotic (temperature, photoperiod) and biotic (host insect or/and host plant) signals for the induction of diapause. We present an overview of the role of these environmental cues in diapause induction in specialist and generalist aphid parasitoids, and discuss possible endocrine factors that may be involved in diapause induction.

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Section: Discussionmentioning

confidence: 99%

Section: Hormonal Control Of Diapause Inductionmentioning

confidence: 92%

Diapause induction in aphid parasitoids

Polgár

Hardie

2000

Entomologia Exp Applicata

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“…The antiserum detects ecdysone, 20-hydroxyecdysone and other ecdysteroid metabolites including 2-deoxy-20-hydroxyecdysone and 2-deoxyecdysone [76], [77], [78]. The standard curve was obtained with 20E (Sigma-Aldrich, USA) and results are expressed as 20E equivalents.…”

Section: Methodsmentioning

confidence: 99%

Tissue Damage Disrupts Developmental Progression and Ecdysteroid Biosynthesis in Drosophila

2012

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In humans, chronic inflammation, severe injury, infection and disease can result in changes in steroid hormone titers and delayed onset of puberty; however the pathway by which this occurs remains largely unknown. Similarly, in insects injury to specific tissues can result in a global developmental delay (e.g. prolonged larval/pupal stages) often associated with decreased levels of ecdysone – a steroid hormone that regulates developmental transitions in insects. We use Drosophila melanogaster as a model to examine the pathway by which tissue injury disrupts developmental progression. Imaginal disc damage inflicted early in larval development triggers developmental delays while the effects are minimized in older larvae. We find that the switch in injury response (e.g. delay/no delay) is coincident with the mid-3rd instar transition – a developmental time-point that is characterized by widespread changes in gene expression and marks the initial steps of metamorphosis. Finally, we show that developmental delays induced by tissue damage are associated with decreased expression of genes involved in ecdysteroid synthesis and signaling.

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“…The colorimetric reaction was measured at 414 nm using the Labsystems Multiskan EX plate reader (Helsinki, Finland). Ecdysteroid titre of each sample was determined by comparison of sample absorbances with the 20-hydroxyecdysone standard curve and expressed as pg of ecdysone equivalents/mg dw (Polgar et al 1996).…”

Section: Ecdysteroid Analysismentioning

confidence: 99%

Endocrine disruption in a terrestrial isopod under exposure to bisphenol A and vinclozolin

Lemos

Gestel²,

Soares

2009

J Soils Sediments

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Background, aim, and scope In the past decade there has been an increasing awareness about the possible consequences of human and wildlife exposure to endocrine disrupting compounds (EDCs). Bisphenol A (BPA) and vinclozolin (Vz) are EDCs which impacts on vertebrates have been largely investigated. Nevertheless, research on invertebrate effects, especially on soil organisms, are still largely underrepresented. This work aims to extend the limited ecotoxicological datasets available and to provide tools to assess the effects of EDCs on the terrestrial species, using Porcellio scaber (Crustacea: Isopoda) as a model organism. Materials and methods Male adult isopods were exposed for 10 weeks to BPA and Ronilan® [containing 50% Vz as active ingredient (a.i.)] at concentrations of 10, 30, 100, 300, and 1,000 mg a.i./kg of soil and compared to nonexposed isopods. We studied the effects of these EDCs on molting and total ecdysteroid (20E) concentration. Young, sexually undifferentiated isopods were also exposed to these compounds (Vz, 5, 10, 25, 50, and 100 mg a.i./kg of soil; and BPA, 10, 25, 50, 150, and 300 mg/kg of soil) for 16 weeks and effects on sex ratio were assessed.

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Comparison of ecdysteroid concentration in different morphs of aphids

Cited by 5 publications

References 25 publications

Diapause induction in aphid parasitoids

Diapause induction in aphid parasitoids

Tissue Damage Disrupts Developmental Progression and Ecdysteroid Biosynthesis in Drosophila

Endocrine disruption in a terrestrial isopod under exposure to bisphenol A and vinclozolin

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