[Frontiers in Bioscience 14, 2657-2665, January 1, 2009]

Genetic basis and impact of tick acaricide resistance

Rodrigo Rosario-Cruz1, Consuelo Almazan2, Robert J. Miller3, Delia Ines Dominguez-Garcia4, Ruben Hernandez-Ortiz1, Jose de la Fuente5,6

1Centro Nacional de Investigacion Disciplinaria en Parasitología Veterinaria Carretera Federal Cuernavaca-Cuautla 8534. Col Progreso., Jiutepec, Morelos. CP 62550, Mexico, 2Facultad de Medicina Veterinaria y Zootecnia, Universidad Autonoma de Tamaulipas, Km. 5 Carretera Victoria-Mante, Cd. Victoria., Tamaulipas, CP 87000, Mexico. 3USDA ARS, Cattle Fever Tick Research Laboratory 22675 North Moorefield Rd., Bldg 6419, Edinburg, Texas 78541. USA, 4Universidad Autonoma Metropolitana Unidad Xochimilco, Posgrado en Ciencias Biologicas, Calzada del hueso 1100, Mexico D.F. C.P. 04960. 5Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University,Stillwater, OK 74078-2007, USA, 6Instituto de Investigacion en Recursos Cinegeticos IREC (CSIC-UCLM-JCCM),Ronda de Toledo s/n, 13005 Ciudad Real, Spain

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Evolutionary aspects of pesticide resistance
4. Acaricide resistance in Mexico
5. Mechanisms of acaricide resistance
5.1. Metabolic detoxification 5.2 .Target site modifications
6. Tick genomics and acaricide resistance
7. Perspectives
8. Acknowledgements
9. References

1. ABSTRACT

Acaricide resistance in Boophilus microplus has been studied for the last 20 years from the toxicology, metabolic and genomic points of view, however, only few methods for molecular detection of resistance have been developed. Despite the relatively poor sensitivity for resistance detection, bioassays remain the method of choice for susceptibility evaluation of tick populations, based on their toxicological response after exposure to acaricides. Metabolic detoxification of acaricides is known to be mediated by multigene- families of enzymes such as GST, Esterases and Mixed Function Oxidases (cytochrome P450). In addition, target site insensitivity has been studied on the sodium channel and acetylcholinesterase genes. The use of genomics to understand acaricide resistance in B. microplus will play a major role in unraveling the molecular mechanisms of resistance. Advances in genomics, will accelerate the development of new diagnostic and immunoprophylactic tools based on new vaccine candidates, and new molecular targets for acaricide resistance detection and improvement of strategies for the control of ticks and tick-borne diseases in tropical and subtropical areas of Mexico.