Honey bee (Apis mellifera) transferrin-gene structure and the role of ecdysteroids in the developmental regulation of its expression

Autor(es)

Nascimento, Adriana Mendes do ; Cuvillier-Hota, Virginie ; Barchuk, Angel Roberto ; Simões, Zilá Luz Paulino ^[4] ; Hartfelder, Klaus

• Tipo de documento: Artigo Científico
• Fonte: Insect Biochemistry and Molecular Biology; v. 34, n. 5, p. 415-424, May 2004.
• Área do conhecimento: Ciências Biológicas - Biologia Geral
• Assunto(s): Imunologia celular Espermatogênese Abelhas Apis mellifera

Resumo

Social life is prone to invasion by microorganisms, and binding of ferric ions by transferrin is an efficient strategy to restrict their access to iron. In this study, we isolated cDNA and genomic clones encoding an Apis mellifera transferrin (AmTRF) gene. It has an open reading frame (ORF) of 2136 bp spread over nine exons. The deduced protein sequence comprises 686 amino acid residues plus a 26 residues signal sequence, giving a predicted molecular mass of 76 kDa. Comparison of the deduced AmTRF amino acid sequence with known insect transferrins revealed significant similarity extending over the entire sequence. It clusters with monoferric transferrins, with which it shares putative iron-binding residues in the N-terminal lobe. In a functional analysis of AmTRF expression in honey bee development, we monitored its expression profile in the larval and pupal stages. The negative regulation of AmTRF by ecdysteroids deduced from the developmental expression profile was confirmed by experimental treatment of spinning-stage honey bee larvae with 20-hydroxyecdysone, and of fourth instar-larvae with juvenile hormone. A juvenile hormone application to spinning-stage larvae, in contrast, bad only a minor effect on AmTRF transcript levels. This is the first study implicating ecdysteroids in the developmental regulation of transferrin expression in an insect species. (AU)

• Processo FAPESP: 99/00719-6 - Abelhas africanizadas: análise integrada do processo de africanização de Apis mellifera com foco sobre determinantes da fertilidade de zangões, rainhas e operárias
• Beneficiário: Zilá Luz Paulino Simões
• Modalidade de apoio: Auxílio à Pesquisa - Temático