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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » LAPRU » Research » Publications at this Location » Publication #348691

Research Project: Genomics of Livestock Pests

Location: Livestock Arthropod Pests Research

Title: Identification of novel cytochrome P450s in the Acari

Author
item Graham, Kirsty - Northumbria University
item Sparagano, Olivier - Northumbria University
item Perez De Leon, Adalberto - Beto
item Bell-sakyi, Lesley - University Of Edinburgh
item Guerrero, Felicito - Felix
item Finn, Robert - Northumbria University

Submitted to: ISSX Online Abstracts, Supplement 7, No. 1, 2012
Publication Type: Proceedings
Publication Acceptance Date: 6/17/2012
Publication Date: 6/12/2017
Citation: Graham, K., Sparagano, O., Perez De Leon, A.A., Bell-Sakyi, L., Guerrero, F., Finn, R. 2017. Identification of novel cytochrome P450s in the Acari. ISSX Online Abstracts, Supplement 7, No. 1, 2012. p. 49.

Interpretive Summary: Cytochrome P450s are the major drug metabolising enzymes found in most organisms, including arthropods. Much of the work within the area of xenobiotic metabolism in this group of animals has centered around mosquitoes. Current research on mosquito species has identified members of the CYP6 and CYP9 Cytochrome P450 protein families as playing an important role in the detoxification of pesticides and development of resistance. In addition to mosquitoes, this phylum contains other medically/veterinary important ectoparasites many of which are members of the Acari subclass, which consists of ticks and mites. The work presented here focuses on the identification of xenobiotic metabolising P450s from the cattle tick Rhipicephalus (Boophilus) microplus, an ectoparasite of cattle and a vector of numerous bovine diseases that cost beef producing countries millions of dollars per year. The research in Acari is currently greatly hindered by the lack of available genome data. However, transcriptomic data are now starting to become available and 115 putative CYP sequences from R. microplus have been identified through bioinformatic analysis. Following the construction of phylogenic trees, these sequences have been grouped into families such that putative CYP6 and CYP9 homologues have now been identified. From these partial DNA sequences, gene specific polymerase chain reaction primers have been designed and used to isolate full length cDNA sequences. The isolation of these CYP protein coding sequences will facilitate detailed characterisation and investigation of the roles of the P450s in acaricide resistance.

Technical Abstract: Cytochrome P450s are the major phase I drug metabolising enzymes found in most organisms, including arthropods. Much of the work within the area of xenobiotic metabolism in this group of animals has centered around mosquito species, e.g. Anopheles gambiae and Culex quinquefasciatus, due to their role as vectors of human disease agents. Current research on these mosquito species has identified members of the CYP6 and CYP9 families as playing an important role in the detoxification of pesticides and development of resistance, most notably, CYP6Z1 and CYP6P3. In addition to mosquitoes this phylum contains other medically/veterinary important ectoparasites, many of which are members of the Acari subclass (ticks and mites). The work presented here focuses on the identification of xenobiotic metabolising P450s from the cattle tick Rhipicephalus (Boophilus) microplus, an ectoparasite of cattle and a vector of numerous diseases most notably babesiosis, that costs beef producing countries millions of dollars each year. To date only 3 CYP genes have been identified within this species, none of which belong to the key CYP3 clade, or have been characterised functionally. The research in Acari is currently greatly hindered by the lack of genome data available. However, transcriptomic data are now starting to become available. Using transcriptomic data, 115 putative CYP sequences from R. microplus were put through detailed bioinformatic analysis. Following the construction of phylogenic trees, these sequences have been grouped into families and putative CYP6 and CYP9 homologues identified. From these partial DNA sequences, gene specific primers (GSP) have been designed and used in 5'/3' RACE reactions to isolate full length cDNA sequences. cDNA was generated from RNA obtained from tick cell cultures (BME/CTVM2). The isolation of these novel CYP cDNAs will facilitate detailed enzymatic characterisation and investigation into their role in pesticide resistance. Finally this data will ultimately assist in designing better/specific, and hopefully more environmentally friendly compounds for the control of these ectoparasites and additionally provide a platform that could be extended to other Acari members.