Transcriptomic analysis of midgut from one of the most threatening pest in Argentina, Anthonomus grandis (Coleoptera: Curculionidae)?

SALVADOR, R.; PRINCIPI, D.; BERRETA, M.; FERNANDEZ, P.; PANIEGO, N.; DOPAZO, J.; SCIOCCO DE CAP, A.; HOPP, H.E.

INSECT MOLECULAR BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014

0962-1075

Cotton boll weevil is a key pest in cotton crops. The larval stage develops within the flower bud using it as food and as protection against its predators. This behaviour difficults both conventional insecticide and biocontrol treatments. At present, genomic data of A. grandis are a limiting requirement to get insights into biological and developmental aspects of this species. In addition, relevant population genetic studies important for epidemiological studies are difficult because very few molecular markers are available, particularly functional markers. Total mRNA isolated from larval midguts was used for the generation of cDNA libraries for pyrosequencing using Roche?s 454 technologies. Sequence reads were assembled and annotated to generate a unigene data set. A total of 400,000 reads from A. grandis midgut with an average length of 237 bp were assembled and combined into 20,915 contigs. The assembled reads fell into 6621 genes models. BlastX search using the NCBI-NR database with a Coleotera filter, showed that 3006 unigenes had significant matches to known sequences. The species showing the highest number of Blast hits was the ?red flour beetle?, Tribolium castaneum (Coleoptera: Tenebrionidae), since it is the only beetle whose genome have been completely sequenced so far. GO mapping analysis evidenced that A. grandis is able to express a diversified number of genes involved in catalytic processing of macromolecules that allows its adaptation to very different feeding source scenarios. Also, transcripts encoding for proteins involved in detoxification mechanisms like as p450 genes, glutathione-S-transferase, and carboxylesterases are expressed. Putative transcripts encoding proteins involved in the initial amplification of the initial iRNA signalling pathway were also represented. This is the first report of a transcriptomic study in A. grandis and the largest set of sequence data reported for this species. We describe a wide variety transcripts and their putative encoded proteins in the larval midgut of this insect providing the basis for comparative studies related to the metabolic regulation in coleopteran species. These data are valuable resources for the design of new control strategies for this pest.