Effects of ultralow doses of fenoxycarb on juvenile hormone-regulated physiological parameters in the silkworm,Bombyx mori L.

Monconduit, Hervé; Mauchamp, Bernard

doi:10.1002/(sici)1520-6327(1998)37:2<178::aid-arch6>3.0.co;2-q

Cited by 32 publications

(16 citation statements)

References 25 publications

(42 reference statements)

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“…All fibers were kept at room temperature, under 60% relative humidity. The fibers from B. mori silkworm cocoon were produced at the former Unité Séricicole Nationale (USN‐INRA), La Mulatière, and degummed (d B. mori ) as previously described . N. madagascariensis silk fibers come from spiders harvested from the wild in the region of Antananarivo, Madagascar .…”

Section: Methodsmentioning

confidence: 99%

Origin of the variability of the mechanical properties of silk fibers: 4. Order/crystallinity along silkworm and spider fibers

Wojcieszak

Percot

Noinville

et al. 2014

J Raman Spectroscopy

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The poor crystallinity of proteic fibers has fuelled an ongoing debate over their exact organization. We present a full‐range Raman comparison of Nephila madagascariensis spider and Bombyx mori silkworm silks that sheds some new light on that matter. On the one hand, a large variability is observed along the fibers in the −200 to 200 cm−1 spectral window, which is sensitive to the long‐range order signature of polyamide chains. This questions the validity of previous literature data considering silk fiber as a homogeneous material. On the other hand, the ‘amide I’ band is almost independent of the targeted point, which sets a limit to this widely used structure probe. In‐line mapping of the fibers showed that the extension of the ordered zones ranges between 1 and 3 µm. The correlation between the macromechanical behavior (the stress–strain curves) and the nanomechanics (Raman low wavenumber signatures) under controlled tensile strain demonstrates a Prevorsek's type microstructure: the macromolecular chains belong to both ordered and amorphous ‘regions’. Copyright © 2014 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

Origin of the variability of the mechanical properties of silk fibers: 4. Order/crystallinity along silkworm and spider fibers

Wojcieszak

Percot

Noinville

et al. 2014

J Raman Spectroscopy

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“…The effects of fenoxycarb on in vivo hormone balance and post‐embryonic development have been studied in detail in the 5th instar of Bombyx mori (Kamimura 1995; Leonardi et al . 1996; Kamimura & Kiuchi 1998; Monconduit & Mauchamp 1998; Dedos & Fugo 1999a) . Our results suggested that day 0 and day 3 of the fifth instar are fenoxycarb‐sensitive days.…”

Section: Discussionmentioning

confidence: 99%

Fenoxycarb modulates ecdysone receptor B1 and programmed cell death of the anterior silk gland of silkworm Bombyx mori

Göncü

Parlak

2011

Entomological Science

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Fenoxycarb, carbamate has been shown to be one of the most potent juvenile hormone analogues against a variety of insect species. In the present study, topical application of fenoxycarb to fifth-instar larvae of the silkworm Bombyx mori (Lepidoptera: Bombycidae) was performed immediately after the fourth ecdysis (on day 0), day 3 and day 6 of the instar and then its effects on the anterior silk glands (ASG) and ecdysone receptor B1 (EcR-B1) protein were investigated during larval pupal development. Fenoxycarb application increased the instar length and prevented metamorphic events, depending on the application time. The ASGs of B. mori undergo programmed cell death during the larval-pupal metamorphosis and an insect steroid, 20-hydroxyecdysone (20E), triggers this cell death. The exact mechanism by which 20E and juvenile hormone regulates programmed cell death in insect tissues is poorly understood. To gain insights into how juvenile hormone regulates metamorphic events like programmed cell death in the anterior silk glands, we analyzed the progression of programmed cell death with morphological observations and biochemical experiments like acid phosphatase activity and DNA electrophoresis. Then we examined the EcR-B1 protein levels and their relationships with programmed cell death. Our results indicated that fenoxycarb modulates programmed cell death of the anterior silk glands and EcR-B1 protein level, depending on the application time. Fenoxycarb may exhibit its effects in at least two different ways: (i) acting on prothoracic gland secretory activity; and/or (ii) regulation of EcR-B1 expression in the anterior silk glands for programmed cell death process.

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“…On the other hand, Masner et al (1983) showed that FC enhances JH-esterase activity in the hemolymph of the lepidopteran Adoxophyies reticulana. Finally, it was demonstrated that FC was still able to induce its effects in allatectomized larvae (Monconduit and Mauchamp, 1998).…”

Section: Introductionmentioning

confidence: 97%

“…The induction of permanent larvae is a well-known effect of JHs or classical JH analogs (JHAs; e.g., methoprene) on silkworm larvae (Akai and Kobayashi, 1971;Sakurai and Imokawa, 1988), and it can be reproduced with FC (Cappellozza et al, 1990(Cappellozza et al, , 1995Plantevin et al, 1991;Kamimura, 1995;Leonardi et al, 1996). However, whereas micrograms of JHs or classical JHAs are needed to produce this effect, only picograms of FC are necessary to induce the same effect (Cappellozza et al 1990(Cappellozza et al , 1995Leonardi et al, 1996;Monconduit and Mauchamp, 1998). FC also induces JH effects on several JH-regulated parameters in the silkworm at these ultra low doses (Monconduit and Mauchamp, 1998).…”

Section: Introductionmentioning

confidence: 99%

“…However, whereas micrograms of JHs or classical JHAs are needed to produce this effect, only picograms of FC are necessary to induce the same effect (Cappellozza et al 1990(Cappellozza et al , 1995Leonardi et al, 1996;Monconduit and Mauchamp, 1998). FC also induces JH effects on several JH-regulated parameters in the silkworm at these ultra low doses (Monconduit and Mauchamp, 1998).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fenoxycarb, a potent contaminant of the silkworm,Bombyx mori L., does not influence its juvenile hormone titer

Monconduit¹,

Mauchamp²

1999

Arch. Insect Biochem. Physiol.

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Fenoxycarb (FC) effects were studied on juvenile hormone (JH) titers and JH‐esterase activities in the silkworm, B. Mori. In the literature, FC was observed to induce high JH titers but also to act without corpora allata (CA). These contradictory results did not permit us to conclude whether FC was a potent JH mimic or it was acting through the enhancement of JH titers in the hemolymph. Analysis of hemolymph JH‐esterase activities during the last larval instar reveals that FC was not a JH‐esterase inhibitor. Considering JHs, only JH II was detected in the European hybrid 200×300. Furthermore, JH titer was exactly identical in control and FC‐treated larvae, i.e., it dropped during the first 2 days of the last larval instar and became undetectable after day 2. This result is important since it contradicts the generally admitted concept that FC was acting by increasing the titer of JH. On the contrary, it was found that, despite its non‐terpenoid chemical structure, FC might be a JH mimic. In addition, FC suspected contamination of mulberry leaves was analyzed from a physiological viewpoint. We observed that "contaminated" mulberry leaves‐fed larvae became permanent larvae through the inhibition of their prothoracic glands (PG) activity and without any modification of their JH titers, i.e., exactly as for FC‐treated larvae. This last point adds information concerning the suspected implication of FC in the induction of the non‐spinning syndrome. Arch. Insect Biochem. Physiol. 40:141–149, 1999. © 1999 Wiley‐Liss, Inc.

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Effects of ultralow doses of fenoxycarb on juvenile hormone-regulated physiological parameters in the silkworm,Bombyx mori L.

Cited by 32 publications

References 25 publications

Origin of the variability of the mechanical properties of silk fibers: 4. Order/crystallinity along silkworm and spider fibers

Origin of the variability of the mechanical properties of silk fibers: 4. Order/crystallinity along silkworm and spider fibers

Fenoxycarb modulates ecdysone receptor B1 and programmed cell death of the anterior silk gland of silkworm Bombyx mori

Fenoxycarb, a potent contaminant of the silkworm,Bombyx mori L., does not influence its juvenile hormone titer

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