Autor(es): Promdonkoy, B.; Promdonkoy, P.; Tanapongpipat, S.; Luxananil, P.; Chewawiwat, N.; Audtho, M.; Panyim, S.

Resumo: The mosquitocidal toxin 1 (mtx1) gene from genomic DNA of B. sphaericus strain 2297 was cloned and expressed in E. coli. DNA sequencing analysis of the cloned gene revealed a single open reading frame encoding an 870-amino acid polypeptide. Expression level of the full-length gene in E. coli was very low even though strong promoter was used or the gene was expressed as a fusion protein. Expression level was highly improved after the putative leader sequence was deleted, and the truncated gene was expressed as a fusion protein with glutathione S-transferase (GST-tMtx1). E. coli cells expressing GST-tMtx1 was highly toxic to Culex quinquefasciatus larvae and showed lower toxicity against Anopheles dirus and Aedes aegypti larvae. Enterobacter amnigenus An11, a mosquito larval gut colonizable bacteria, transformed with the cloned gene exhibited mosquito larvicidal activity. Result suggested that there is a potential to develop this protein to be used as an alternative mosquito control agent.

Palavras-Chave: Biological control; Toxicants; Microbiology; Pest control; Larval development; Strains; Aquatic insects; Gene expression; DNA sequencing; Gut; Cloning; Toxicity; Fusion protein; Glutathione transferase; Open reading frames; Larvicides; Toxins; Culex quinquefasciatus; Enterobacter amnigenus; Aedes aegypti; Escherichia coli; Bacillus sphaericus; Anopheles dirus

Imprenta: Current Microbiology, v. 49, n. 2, p. 84-88, 2004.

Descritores: Aedes aegypti - Cell ; Aedes aegypti - DNA ; Aedes aegypti - Proteins ; Aedes aegypti - Larvicide

Data de Publicação: 2004