title: Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.
abstract: Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Cellular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Alexandre Augusto Pereira
authors.initials: AA
authors.lastname: Firmino
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Biology Molecular, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: Fernando Campos de Assis
authors.initials: FC
authors.lastname: Fonseca
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Genomic Sciences and Biotechnology, Universidade Católica de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: Leonardo Lima Pepino
authors.initials: LL
authors.lastname: de Macedo
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Biology Molecular, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: Roberta Ramos
authors.initials: RR
authors.lastname: Coelho
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Biology Molecular, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: José Dijair
authors.initials: JD
authors.lastname: Antonino de Souza
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil.
authors.forename: Roberto Coiti
authors.initials: RC
authors.lastname: Togawa
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil.
authors.forename: Orzenil Bonfim
authors.initials: OB
authors.lastname: Silva-Junior
authors.affiliation: Graduate Program in Biology Molecular, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: Georgios Joannis
authors.initials: GJ
authors.lastname: Pappas
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil.
authors.forename: Maria Cristina Mattar
authors.initials: MC
authors.lastname: da Silva
authors.affiliation: Plateau Microscopique, Institut National de la Recherche Agronomique, Sophia-Antipolis, France.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Engler
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil ; Graduate Program in Genomic Sciences and Biotechnology, Universidade Católica de Brasília, Brasília, Distrito Federal, Brazil.
authors.forename: Maria Fatima
authors.initials: MF
authors.lastname: Grossi-de-Sa
mesh_terms: D000818:Animals; D003368:Gossypium / Q000469:parasitology; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics; D034622:RNA Interference / Q000502:physiology*; D013045:Species Specificity; D059467:Transcriptome / Q000502:physiology*; D048889:Weevils / Q000235:genetics / Q000378:metabolism*
chemical_list: D019476:Insect Proteins