title: Recent worldwide expansion of Nosema ceranae (Microsporidia) in Apis mellifera populations inferred from multilocus patterns of genetic variation.
abstract: Nosema ceranae has been found infecting Apismellifera colonies with increasing frequency and it now represents a major threat to the health and long-term survival of these honeybees worldwide. However, so far little is known about the population genetics of this parasite. Here, we describe the patterns of genetic variation at three genomic loci in a collection of isolates from all over the world. Our main findings are: (i) the levels of genetic polymorphism (πS≈1%) do not vary significantly across its distribution range, (ii) there is substantial evidence for recombination among haplotypes, (iii) the best part of the observed genetic variance corresponds to differences within bee colonies (up to 88% of the total variance), (iv) parasites collected from Asian honeybees (Apis cerana and Apis florea) display significant differentiation from those obtained from Apismellifera (8-16% of the total variance, p<0.01) and (v) there is a significant excess of low frequency variants over neutral expectations among samples obtained from A. mellifera, but not from Asian honeybees. Overall these results are consistent with a recent colonization and rapid expansion of N. ceranae throughout A. mellifera colonies.
authors.affiliation: Laboratorio de Patología Apícola, Centro Apícola Regional, Consejería de Agricultura, Gobierno de Castilla-La Mancha, 19180 Marchamalo, Spain; Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Gómez-Moracho
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain; Departamento de Anatomía Patolóxica e Ciencias Forenses, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Bartolomé
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain; Departamento de Anatomía Patolóxica e Ciencias Forenses, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Bello
authors.affiliation: Laboratorio de Patología Apícola, Centro Apícola Regional, Consejería de Agricultura, Gobierno de Castilla-La Mancha, 19180 Marchamalo, Spain; Instituto de Recursos Humanos para la Ciencia y la Tecnología (INCRECYT), Fundación Parque Científico y Tecnológico de Albacete, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Martín-Hernández
authors.affiliation: Laboratorio de Patología Apícola, Centro Apícola Regional, Consejería de Agricultura, Gobierno de Castilla-La Mancha, 19180 Marchamalo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Higes
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain; Departamento de Anatomía Patolóxica e Ciencias Forenses, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain. Electronic address: xulio.maside@usc.es.
authors.forename: X
authors.initials: X
authors.lastname: Maside
mesh_terms: D000818:Animals; D001516:Bees / Q000469:parasitology*; D017125:Genes, Protozoan; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D058885:Multilocus Sequence Typing; D016818:Nosema / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny; D011995:Recombination, Genetic
keywords: Demographic history; Diversity; Nosema ceranae; Polar tube proteins; Population structure; Recombination