Microarray analysis of gene expression in acaricide exposed Rhipicephalus (Boophilus) microplus.

A R. microplus microarray was used to study differential gene expression in acaricide exposed larvae from an amitraz-resistant strain. The acaricide treatments were: organophosphate (OP), pyrethroid, ivermectin, and amitraz. The microarrays contained over 13,000 probes corresponding to each member of R. microplus gene index ESTs previously described (http://compbio.dfci.harvard.edu/tgi/cgi-bin/tgi/gimain.pl?gudb=b_microplus). Serial analysis of gene expression (SAGE) data from the OP treated R. microplus was used to verify the OP microarray data. The expression profiles of selected transcripts were verified by real time PCR. Among the significantly differentially expressed genes, were a tick legumain, involved in blood digestion, gluthathione S-transferase (GST), a detoxification enzyme involved in pesticide resistance, acyltransferase, several putative salivary sulfotransferases, and a glutamate receptor. **Note: contact person: Felix D. Guerrero email: felix.guerrero@ars.usda.gov Keywords: Rhipicephalus (Boophilus) microplus, acaricide resistance genes, organophosphates OP, microarrays, detoxification enzymes. Overall design: In the study presented here, 10 hybridizations were preformed. Two technical replicates for each treatment. There were no biological replicates included in this study due to limitations on biomaterials. Expression profiles for 13601 unique ESTs were analyzed.