Regulation of prothoracic gland ecdysteroidogenic activity leading to pupal metamorphosis

Takaki, Keiko; Sakurai, Shunsuke

doi:10.1016/j.ibmb.2003.06.006

Cited by 32 publications

(30 citation statements)

References 40 publications

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“…13) Juvenile hormone (JH) has also been reported to suppress the gland during the early stages of the last instar larvae in B. mori. [14][15][16] In this study, we found that BRFa and JH also modulate the expression of certain P450 genes in the PG of B. mori. Our results suggest that multiple factors differentially regulate the expression of the P450 genes, achieving a complex developmental fluctuation of basal PG activity.…”

supporting

confidence: 52%

“…16) This autonomous activation might be mediated by the positive feedback effects of ecdysteroids on the PG, although the existence of unknown autocrine factors has also been indicated. 15,24,25) In order to test this hypothesis, the long-term PG culture system was used. Every 2 d of culture, 5-7 glands were removed from each group, and the expression levels of the ecdysteroidogenic P450 genes were determined (Fig.…”

Section: )mentioning

confidence: 99%

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Differential Regulation of Ecdysteroidogenic P450 Gene Expression in the Silkworm,Bombyx mori

Yamanaka

Honda

Osato

et al. 2007

Bioscience, Biotechnology, and Biochemistry

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The regulatory mechanisms of ecdysteroidogenic P450 gene expression were investigated in the silkworm, Bombyx mori. Bommo-FMRFamide (BRFa), a neural suppressor of prothoracic gland (PG) activity, was found to suppress the expression of several P450 genes induced by prothoracicotropic hormone (PTTH) in the PG. A transcription inhibitor suppressed PTTH-induced expression of the P450 genes and the opposing effects of BRFa, while their short-term effects on ecdysteroidogenesis remained unchanged. This result suggests that the effects of these factors on the P450 gene transcripts become obvious on a longer time scale. Moreover, spontaneous expression of a P450 gene was observed in long-term PG culture, and was repressed by juvenile hormone. These results explain well the developmental fluctuation patterns of the P450 gene transcripts in the PG, indicating that multiple factors coordinate to regulate basal PG activity during insect development.

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confidence: 52%

Section: )mentioning

confidence: 99%

Differential Regulation of Ecdysteroidogenic P450 Gene Expression in the Silkworm,Bombyx mori

Yamanaka

Honda

Osato

et al. 2007

Bioscience, Biotechnology, and Biochemistry

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“…2A) are correlated with the fluctuation of hemolymph ecdysteroid titer in the late larval stages of silkworm ( Fig. 2B) (Sakurai et al, 1998;Takaki and Sakurai, 2003;Koyama et al, 2004), indicating that these genes are influenced by endogenous 20E titer during those stages and may have specific function in distinct physiological and developmental context. The temporal expression patterns also showed high levels of transcripts in the fifth instar larvae ( Fig.…”

Section: Fig 2 a Temporal Expression Analysis Of 20e-induced Genesmentioning

confidence: 92%

“…We analyzed the temporal expression of these three genes using RNA samples isolated from the brains of larvae from the third instar day-0 through the fifth instar day-8. The expression of two genes, UP4 and UP5, showed a better correlation with the hemolymph ecdysteroid titer (Sakurai et al, 1998;Takaki and Sakurai, 2003; Koyama et al, 2004; Fig. 2B), while no significant relation was found for UP22 in any stage ( Fig.…”

Section: Temporal Expression Analysismentioning

confidence: 95%

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Identification of 20-Hydroxyecdysone-Inducible Genes from Larval Brain of the Silkworm, Bombyx mori, and Their Expression Analysis

et al. 2012

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Effects of RH‐5992 on ecdysteroidogenesis of the prothoracic glands during the fourth larval instar of the silkworm, Bombyx mori

Lin

et al. 2008

Arch Insect Biochem Physiol

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Stage-dependent effects of RH-5992 on ecdysteroidogenesis of the prothoracic glands during the fourth larval instar of the silkworm, Bombyx mori, were studied in the present report. When larvae were treated with RH-5992 during the early stages of the fourth larval instar (between day 0 and day 1), initially ecdysteroid levels in the hemolymph were inhibited. However, 24 h after RH-5992 application, ecdysteroid levels were greatly increased as compared with those treated with acetone. The examination of the in vitro prothoracic gland activity upon RH-5992 application during the early stages of the fourth larval instar confirmed a short-term inhibitory effect. When RH-5992 was applied to the later stages of the fourth larval instar, no effects on both hemolymph ecdysteroid levels and prothoracic gland activity were observed. Addition of RH-5992 to incubation medium strongly inhibited ecdysteroid secretion by the prothoracic glands from the early fourth instar, indicating direct action of RH-5992 on ecdysteroidogenesis by prothoracic glands. Four hours after application with RH-5992 on day 1.5, prothoracic glands still showed an activated response to PTTH in both PTTH-cAMP signaling and the extracellular signal-regulated kinase (ERK) signaling. Moreover, addition of RH-5992 to incubation medium did not interfere with the stimulatory effect of the glands to PTTH in ecdysteroidogenesis. These results indicated that both PTTH-cAMP signaling and PTTH-ERK signaling may not be involved in short-term inhibitory regulation by RH-5992. Arch. Insect Biochem. Physiol. 68:197-205, 2008.

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Regulation of prothoracic gland ecdysteroidogenic activity leading to pupal metamorphosis

Cited by 32 publications

References 40 publications

Differential Regulation of Ecdysteroidogenic P450 Gene Expression in the Silkworm,Bombyx mori

Differential Regulation of Ecdysteroidogenic P450 Gene Expression in the Silkworm,Bombyx mori

Identification of 20-Hydroxyecdysone-Inducible Genes from Larval Brain of the Silkworm, Bombyx mori, and Their Expression Analysis

Effects of RH‐5992 on ecdysteroidogenesis of the prothoracic glands during the fourth larval instar of the silkworm, Bombyx mori

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