Developmental profile of the changes in the prothoracicotropic hormone titer in hemolymph of the silkworm Bombyx mori: correlation with ecdysteroid secretion

Mizoguchi, Akira; Ohashi, Yoshi; Hosoda, Kazutaka; Ishibashi, Jun Ichiro; Kataoka, Hiroshi

doi:10.1016/s0965-1748(00)00127-2

Cited by 117 publications

(103 citation statements)

References 25 publications

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“…Consistent with the microarray data, Northern blot analysis revealed that changes in mRNA expression level of these genes were positively correlated with the changes of hemolymph ecdysteroid titers during Bombyx development (Fig. 1A) (31)(32)(33). Maximal expression levels of prgv0240 and prgv0649 were observed at the V5-V6 and W1 stages, respectively (Fig.…”

Section: Identification Of Bombyx Cyp306a1supporting

confidence: 81%

“…Maximal expression levels of prgv0240 and prgv0649 were observed at the V5-V6 and W1 stages, respectively (Fig. 1A), indicating that expression of these genes reached their maximum before the peak of the ecdysone titer (W2-W3) (31,33). Expression of the two genes in various tissues of the W1 stage of fifth instar larvae was examined by reverse transcription-PCR.…”

Section: Identification Of Bombyx Cyp306a1mentioning

confidence: 99%

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CYP306A1, a Cytochrome P450 Enzyme, Is Essential for Ecdysteroid Biosynthesis in the Prothoracic Glands of Bombyx and Drosophila

Niwa¹,

Matsuda

Yoshiyama

et al. 2004

Journal of Biological Chemistry

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276

251

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Ecdysteroids mediate a wide variety of developmental and physiological events in insects. In the postembryonic development of insects, ecdysone is synthesized in the prothoracic gland (PG). Although many studies have revealed the biochemical and physiological properties of the enzymes for ecdysteroid biosynthesis, most of the molecular identities of these enzymes have not been elucidated. Here we describe an uncharacterized cytochrome P450 gene, designated Cyp306a1, that is essential for ecdysteroid biosynthesis in the PGs of the silkworm Bombyx mori and fruit fly Drosophila melanogaster. Using the microarray technique for analyzing gene expression profiles in PG cells during Bombyx development, we identified two PG-specific P450 genes whose temporal expression patterns are correlated with changes in ecdysteroid titer during development. Amino acid sequence analysis showed that one of the Bombyx P450 genes belongs to the CYP306A1 subfamily. The temporal and spatial expression pattern of the Drosophila Cyp306a1 homolog is essentially the same as that of Bombyx Cyp306a1. We also found that Drosophila Cyp306a1 is disrupted in the phantom (phm) mutant, known also as the Halloween mutant. The morphological defects and decreased expression of ecdysone-inducible genes in phm suggest that this mutant cannot produce a high titer of ecdysone. Finally we demonstrate that S2 cells transfected with Cyp306a1 convert ketodiol to ketotriol via carbon 25 hydroxylation. These results strongly suggest that CYP306A1 functions as a carbon 25 hydroxylase and has an essential role in ecdysteroid biosynthesis during insect development.

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Section: Identification Of Bombyx Cyp306a1supporting

confidence: 81%

Section: Identification Of Bombyx Cyp306a1mentioning

confidence: 99%

CYP306A1, a Cytochrome P450 Enzyme, Is Essential for Ecdysteroid Biosynthesis in the Prothoracic Glands of Bombyx and Drosophila

Niwa¹,

Matsuda

Yoshiyama

et al. 2004

Journal of Biological Chemistry

Self Cite

276

251

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“…The difference in this species and M. sexta may be explained by the difference in growth pattern of the prothoracic glands. Specifically, prothoracic gland growth in B. mori occurs concurrently with the commitment peak of ecdysone when the larvae have ceased feeding (Mizoguchi et al, 2001). In contrast, the majority of the growth in the glands of M. sexta occurs prior to the commitment peak, while the larvae are still feeding.…”

Section: Discussionmentioning

confidence: 99%

Nutritional sensitivity of fifth instar prothoracic glands in the tobacco hornworm, Manduca sexta

Walsh

Smith

2011

Journal of Insect Physiology

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The tobacco hornworm, Manduca sexta, has been a useful model for studying insect endocrinology. In M. sexta the majority of growth occurs during the fifth (final) larval stage. This growth is concurrent with endocrine changes that lead to a metamorphic molt. Past research has focused on the interplay of three growth hormones: juvenile hormone (JH), prothoracicotropic hormone (PTTH) and ecdysone, in regulating metamorphosis. The prothoracic glands, source of ecdysteroid molting hormones in insects, play a crucial role in coordinating growth. Insulin/insulin-like growth factor (IGF) signaling has been shown to regulate growth and secretion of steroidogenic tissues in both vertebrates and invertebrates, but it had yet to be well-characterized in M. sexta.In this dissertation I examined the role of insulin-directed growth in prothoracic glands during both normal larval development and in response to nutrient deprivation. In particular, I predicted that in response to a reduction in nutrients, the prothoracic glands would stop growing and ecdysone secretion would be reduced. Changes were assessed in actin abundance and in two nutritionally sensitive transcripts, insulin receptor and 4EBP.Actin abundance in prothoracic glands increased in the first four days of this stage, demo nstrating significant growth. Actin decreased in glands from starved larvae, indicating a cessation of growth. Both insulin receptor and 4EBP transcript were present during normal larval development. As expected, both insulin receptor and 4EBP transcript increased in response to starvation. This research was the first demonstration of insulin signaling in prothoracic glands of fifth instar M. sexta larvae, and revealed nutritional sensitivity of the prothoracic glands. 5Finally, ecdysone assays were conducted to determine the impact of nutrition on glandular secretory capacity. Starved larvae were unable to secrete as much ecdysone as fed controls. Injections of insulin were unable to rescue the ability of the glands to secrete high levels of ecdysone. This demonstrated that although insulin signaling was correlated with normal growth of the glands, insulin is not sufficient to impact the ability of the glands to secrete ecdysone in the absence of nutrie nts. 6 This thesis is dedicated to my parents,Robert and Angela Walsh, whose love and support made this dissertation possible.

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“…1, D-H). The dynamic expression of Antp, POU-M2, and the steroidogenic enzyme genes positively correlated with the changes in the ecdysone titer during the final instar of the larval stage in the silkworm (34).…”

Section: Proximal Promoters Of Silkworm Steroidogenic Enzyme Genesmentioning

confidence: 91%

The Homeodomain Transcription Factors Antennapedia and POU-M2 Regulate the Transcription of the Steroidogenic Enzyme Gene Phantom in the Silkworm

Meng

Cheng

Peng

et al. 2015

Journal of Biological Chemistry

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Background:The transcriptional regulation of steroidogenic enzymes in the silkworm remains poorly understood. Results: Antp and POU-M2 are expressed in the PG and regulate the transcription of Phantom. Conclusion: Antp and POU-M2 coordinate the transcription of Phantom via a protein interaction. Significance: Our study indicates new roles for homeodomain proteins in regulating insect ecdysteroidogenesis.

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Developmental profile of the changes in the prothoracicotropic hormone titer in hemolymph of the silkworm Bombyx mori: correlation with ecdysteroid secretion

Cited by 117 publications

References 25 publications

CYP306A1, a Cytochrome P450 Enzyme, Is Essential for Ecdysteroid Biosynthesis in the Prothoracic Glands of Bombyx and Drosophila

CYP306A1, a Cytochrome P450 Enzyme, Is Essential for Ecdysteroid Biosynthesis in the Prothoracic Glands of Bombyx and Drosophila

Nutritional sensitivity of fifth instar prothoracic glands in the tobacco hornworm, Manduca sexta

The Homeodomain Transcription Factors Antennapedia and POU-M2 Regulate the Transcription of the Steroidogenic Enzyme Gene Phantom in the Silkworm

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