Please cite this article in press as: Kanduma, E.G., et al., Multi-locus genotyping reveals absence of genetic structure in field populations of the brown ear tick (Rhipicephalus appendiculatus) in Kenya. Ticks Tick-borne Dis. (2015), http://dx.doi.org/10.1016/j.ttbdis.2015.08.001 ARTICLE IN PRESS G Model TTBDIS-528; No. of Pages 10 Ticks and Tick-borne Diseases xxx (2015) xxx–xxx Contents lists available at ScienceDirect Ticks and Tick-borne Diseases j ourna l h o me page: w ww.elsevier.com/locate/ttbdis Original article Multi-locus genotyping reveals absence of genetic structure in field populations of the brown ear tick (Rhipicephalus appendiculatus) in Kenya Esther G. Kanduma a,b,∗,1 , Joram M. Mwacharo c,d,1 , Stephen Mwaura e , Joyce N. Njuguna a , Inosters Nzuki a , Peter W. Kinyanjui b , Naftaly Githaka e , Heloise Heyne f , Olivier Hanotte c , Robert A. Skilton a,2 , Richard P. Bishop e a Biosciences eastern and central Africa – International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, 00100 Nairobi, Kenya b Department of Biochemistry, School of Medicine, University of Nairobi, P.O. Box 30197, Nairobi, Kenya c Centre for Genetics and Genomics, School of Life Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK d International Centre for Agricultural Research in Dry Areas (ICARDA), P.O. Box 5689, Addis Ababa, Ethiopia e International Livestock Research Institute (ILRI), P. O. Box 30709, 00100 Nairobi, Kenya f Parasites, Vectors, & Vector-Borne Diseases Progamme, ARC-Onderstepoort Veterinary Institute, Pretoria, South Africa a r t i c l e i n f o Article history: Received 23 April 2015 Received in revised form 31 July 2015 Accepted 3 August 2015 Available online xxx Keywords: ECF EST-SSR Genetic diversity Microsatellites Minisatellites Theileria parva a b s t r a c t Rhipicephalus appendiculatus is an important tick vector of several pathogens and parasitizes domes- tic and wild animals across eastern and southern Africa. However, its inherent genetic variation and population structure is poorly understood. To investigate whether mammalian host species, geographic separation and resulting reproductive isolation, or a combination of these, define the genetic structure of R. appendiculatus, we analyzed multi-locus genotype data from 392 individuals from 10 geographic loca- tions in Kenya generated in an earlier study. These ticks were associated with three types of mammalian host situations; (1) cattle grazing systems, (2) cattle and wildlife co-grazing systems (3) wildlife grazing systems without livestock. We also analyzed data from 460 individuals from 10 populations maintained as closed laboratory stocks and 117 individuals from five other species in the genus Rhipicephalus. The pattern of genotypes observed indicated low levels of genetic differentiation between the ten field popu- lations (F ST = 0.014 ± 0.002) and a lack of genetic divergence corresponding to the degree of separation of the geographic sampling locations. There was also no clear association of particular tick genotypes with specific host species. This is consistent with tick dispersal over large geographic ranges and lack of host specificity. In contrast, the 10 laboratory populations (F ST = 0.248 ± 0.015) and the five other species of Rhipicephalus (F ST = 0.368 ± 0.032) were strongly differentiated into distinct genetic groups. Some labora- tory bred populations diverged markedly from their field counterparts in spite of originally being sampled from the same geographic locations. Our results demonstrate a lack of defined population genetic dif- ferentiation in field populations of the generalist R. appendiculatus in Kenya, which may be a result of the frequent anthropogenic movement of livestock and mobility of its several wildlife hosts between different locations. © 2015 Elsevier GmbH. All rights reserved. 1. Introduction Rhipicephalus appendiculatus (brown ear tick; Acari, Ixodidae) is the most important vector of Theileria parva, which causes East ∗ Corresponding author at: Department of Biochemistry, School of Medicine, Uni- versity of Nairobi, P.O. Box 30197, 00100 Nairobi, Kenya. E-mail address: ekanduma@yahoo.co.uk (E.G. Kanduma). 1 These authors contributed equally to this work. 2 Current address: International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, 00100 Nairobi, Kenya. Coast fever (ECF) in cattle in eastern, central and southern Africa (Perry et al., 1990). Adults of the tick mainly infest large ungulates, both domestic – particularly cattle – and wild species such as Cape buffalo (Syncerus caffer), and various other bovids including water- buck (Kobus ellipsiprymnus) and blue wildebeest (Connochaetes taurinus) (Walker et al., 2000). The nymphal and larval stages often infest smaller mammals, particularly hares (Lepus sp.). R. appen- diculatus is an important vector of various pathogens of economic and veterinary significance, particularly the protozoan T. parva but also Nairobi sheep disease virus, the Thogoto virus and Rick- ettsia conorii (Perry et al., 2002; Minjauw and McLeod, 2003). The http://dx.doi.org/10.1016/j.ttbdis.2015.08.001 1877-959X/© 2015 Elsevier GmbH. All rights reserved.