Submitted to: National Center for Biotechnology Information (NCBI)
Publication Type: Other
Publication Acceptance Date: 5/8/2006
Publication Date: 6/14/2007
Publication URL: http://www.ncbi.nlm.nih.gov
Citation: Guerrero, F. 2007. Rhipicephalus (Boophilus) microplus pyarethroid-metabolizing esterase gene structure. National Center for Biotechnology Information (NCBI). Available: http://www.ncbi.nlm.nih.gov. Assession numbers DQ533868-DQ533870. Interpretive Summary: Boophilus ticks are important vectors of pathogens that affect the global cattle population and are responsible for significant production losses to cattle producers in much of Africa, Central and South America and Australia. These ticks are controlled primarily by pesticide application, however, resistance is becoming a problem and new control technologies are needed. The availability of DNA sequence data has revolutionized approaches to the study of biological systems and individual species. We have identified the gene promoter and gene coding sequences from a tick protein that can degrade pyrethroid-based acaricides, enabling a tick possessing this protein to survive pyrethroid treatments. The sequences have been submitted and published under GenBank Accession numbers DQ533868-DQ533870.
Technical Abstract: A population of Rhipicephalus (Boophilus) microplus, designated Coatzacoalcos, obtained near Veracruz, Mexico was found to possess a high level of resistance to pyrethroid-based acaricides. Bioassay, biochemical and molecular analysis had previously shown the resistance could primarily be attributed to a highly active pyrethroid-metabolizing esterase designated CzEST9. We cloned and sequenced the entire CzEST9 coding region from a susceptible R. microplus reference strain (Deutsch strain: GenBank Accession No. DQ533868), including introns and over 1.0 kb upstream from the transcription start site, and compared the 1.0 kb upstream region sequence between the resistant Coatzacoalcos strain (DQ533870), the Deutsch strain, and a second susceptible strain (Munoz strain: GenBank Accession No. DQ533869). Four variant nucleotides were found and a TGA trinucleotide occurred as either 5 or 9 tandem repeats. However, further experiments showed none of these promoter region differences could be clearly associated with a pyrethroid resistant phenotype, thus we concluded that differences in gene promoter sequence were not responsible for the pyrethroid resistance mechanism in the Cz strain.