Dermacentor reticulatus – a tick on its way from glacial refugia to a panmictic Eurasian population

Branka Bilbija (1) , Cäcilia Spitzweg (2) , Ivo Papoušek (1) , Uwe Fritz (2) , Gábor Földvári (3) , Martin Mullett (4) , Flora Ihlow (2) , Hein Sprong (5) , Kristína Civáňová Křížová (6) , Nikolay Anisimov (7) , Oxana Belova (8) , Sarah Bonnet (9, 10) , Elizabeth Bychkova (11) , Aleksandra Czułowska (12) , Georg Duscher (13, 14) , Manoj Fonville (5) , Olaf Kahl , Grzegorz Karbowiak (15) , Ivan Kholodilov (16) , Dorota Kiewra (12) , Stjepan Krčmar (17) , Gulzina Kumisbek (18) , Natalya Livanova (19) , Igor Majláth (20) , Maria Teresa Manfredi (21) , Andrei Mihalca (22) , Guadalupe Miró (23) , Sara Moutailler (24) , Igor Nebogatkin (25, 26) , Snežana Tomanović (27) , Zati Vatansever (28) , Marya Yakovich (11) , Sergio Zanzani (21) , Pavel Široký (1)

1 VFU - University of Veterinary and Pharmaceutical Sciences [Brno]
2 Senckenberg Naturhistorische Sammlungen Dresden
3 Centre for Ecological Research [Budapest]
4 MENDELU - Mendel University in Brno
5 RIVM - National Institute for Public Health and the Environment [Bilthoven]
6 MUNI - Masaryk University [Brno]
7 Tyumen State University
8 Chumakov Institute of Poliomyelitis and Viral Encephalities [Moscou]
9 Génétique fonctionnelle des maladies infectieuses - Functional Genetics of Infectious Diseases
10 DEPT SA - Département Santé Animale
11 Scientific and Practical Center of the National Academy of Sciences of Belarus on Bioresources [Minsk]
12 UWr - University of Wrocław [Poland]
13 Vetmeduni - University of Veterinary Medicine [Vienna]
14 Austrian Agency for Health and Food Safety (AGES)
15 Witold Stefanski Institute of Parasitology
16 Chumakov Institute of Poliomyelitis and Viral Encephalitides
17 Josip Juraj Strossmayer University of Osijek
18 KazNU - Al-Farabi Kazakh National University [Almaty]
19 Institute of Systematics and Ecology of Animals, Novosibirsk, Russia.
20 Pavol Jozef Šafárik University
21 UNIMI - Università degli Studi di Milano = University of Milan
22 University of Agricultural Sciences and Veterinary Medicine Cluj Napoca = Universitatea de Științe Agricole și Medicină Veterinară Cluj-Napoca
23 UCM - Universidad Complutense de Madrid = Complutense University of Madrid [Madrid]
24 BIPAR - Biologie moléculaire et immunologie parasitaires et fongiques
25 I.I. Schmalhausen Institute of Zoology of NASU
26 National center for public health [Hungary]
27 University of Belgrade [Belgrade]
28 Kafkas University

The ornate dog tick (Dermacentor reticulatus) shows a recently expanding geographic distribution. Knowledge on its intraspecific variability, population structure, rate of genetic diversity and divergence, including its evolution and geographic distribution, is crucial to understand its dispersal capacity. All such information would help to evaluate the potential risk of future spread of associated pathogens of medical and veterinary concern. A set of 865 D. reticulatus ticks was collected from 65 localities across 21 countries, from Portugal in the west to Kazakhstan and southern Russia in the east. Cluster analyses of 16 microsatellite loci were combined with nuclear (ITS2, 18S) and mitochondrial (12S, 16S, COI) sequence data to uncover the ticks’ population structures and geographical patterns. Approximate Bayesian computation was applied to model evolutionary relationships among the found clusters. Low variability and a weak phylogenetic signal showing an east–west cline were detected both for mitochondrial and nuclear sequence markers. Microsatellite analyses revealed three genetic clusters, where the eastern and western cluster gradient was supplemented by a third, northern cluster. Alternative scenarios could explain such a tripartite population structure by independent formation of clusters in separate refugia, limited gene flow connected with isolation by distance causing a “bipolar pattern”, and the northern cluster deriving from admixture between the eastern and western populations. The best supported demographic scenario of this tick species indicates that the northern cluster derived from admixture between the eastern and western populations 441 (median) to 224 (mode) generations ago, suggesting a possible link with the end of the Little Ice Age in Europe.

Keywords: Divergence; Glacial refugia; Ixodida; Microsatellites; Multigene sequence analysis; Palaearctic; Vectors

Domains: Life Sciences [q-bio]

Branka Bilbija, Cäcilia Spitzweg, Ivo Papoušek, Uwe Fritz, Gábor Földvári, et al.. Dermacentor reticulatus – a tick on its way from glacial refugia to a panmictic Eurasian population. International Journal for Parasitology, 2023, 53 (2), pp.91-101. ⟨10.1016/j.ijpara.2022.11.002⟩. ⟨anses-03942971⟩