Hormonal control of a metamorphosis-specific transcriptional factor Broad-Complex in silkworm.
Comp Biochem Physiol B Biochem Mol Biol
; 139(4): 753-61, 2004 Dec.
Article
em En
| MEDLINE
| ID: mdl-15581808
ABSTRACT
Insect metamorphosis is induced by the steroid 20-hydroxyecdysone (20E) in the absence of sesquiterpenoid juvenile hormone (JH). In Drosophila melanogaster, the Broad-Complex (BR-C) transcriptional factor plays critical roles during metamorphosis. We isolated cDNAs encoding BR-C in the silkworm Bombyx mori and examined their mRNA expression. cDNAs for three BR-C isoforms with zinc finger pairs (Z1, Z2 and Z4) and four isoforms lacking them were cloned. Their mRNAs were expressed in multiple tissues at the larval-pupal metamorphosis. In the anterior silk gland, BR-C mRNAs were expressed at the end of the last larval instar but not expressed during the penultimate instar. 20E administration induced BR-C mRNA expression and JH suppressed 20E-induced BR-C expression in this tissue both in vivo and in vitro. Thus, BR-C mRNAs are inducible by 20E only in the absence of JH, a finding that explains their metamorphosis-specific expression.
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Base de dados:
MEDLINE
Assunto principal:
Bombyx
/
Fatores de Transcrição
/
Regulação da Expressão Gênica no Desenvolvimento
/
Ecdisterona
/
Hormônios Juvenis
/
Metamorfose Biológica
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article