title: Genome-wide signatures of population bottlenecks and diversifying selection in European wolves.
abstract: Genomic resources developed for domesticated species provide powerful tools for studying the evolutionary history of their wild relatives. Here we use 61K single-nucleotide polymorphisms (SNPs) evenly spaced throughout the canine nuclear genome to analyse evolutionary relationships among the three largest European populations of grey wolves in comparison with other populations worldwide, and investigate genome-wide effects of demographic bottlenecks and signatures of selection. European wolves have a discontinuous range, with large and connected populations in Eastern Europe and relatively smaller, isolated populations in Italy and the Iberian Peninsula. Our results suggest a continuous decline in wolf numbers in Europe since the Late Pleistocene, and long-term isolation and bottlenecks in the Italian and Iberian populations following their divergence from the Eastern European population. The Italian and Iberian populations have low genetic variability and high linkage disequilibrium, but relatively few autozygous segments across the genome. This last characteristic clearly distinguishes them from populations that underwent recent drastic demographic declines or founder events, and implies long-term bottlenecks in these two populations. Although genetic drift due to spatial isolation and bottlenecks seems to be a major evolutionary force diversifying the European populations, we detected 35 loci that are putatively under diversifying selection. Two of these loci flank the canine platelet-derived growth factor gene, which affects bone growth and may influence differences in body size between wolf populations. This study demonstrates the power of population genomics for identifying genetic signals of demographic bottlenecks and detecting signatures of directional selection in bottlenecked populations, despite their low background variability.
authors.affiliation: 1] School of Life Sciences, University of Lincoln, Lincoln, UK [2] Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Pilot
authors.affiliation: Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome and Ozzano Emilia (BO), Italy.
authors.forename: C
authors.initials: C
authors.lastname: Greco
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: vonHoldt
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Jędrzejewska
authors.affiliation: 1] Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Rome and Ozzano Emilia (BO), Italy [2] Aalborg University, Department 18, Section of Environmental Engineering, Aalborg, Denmark.
authors.forename: E
authors.initials: E
authors.lastname: Randi
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Jędrzejewski
authors.affiliation: Institute of Zoology, National Academy of Sciences of Belarus, Minsk, Belarus.
authors.forename: V E
authors.initials: VE
authors.lastname: Sidorovich
authors.affiliation: Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Ostrander
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Wayne
mesh_terms: D000818:Animals; D005061:Europe, Eastern; D040961:Genetic Drift; D014644:Genetic Variation; D005828:Genetics, Population; D007558:Italy; D025341:Principal Component Analysis; D013030:Spain; D019596:Wolves / Q000145:classification / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics