title: Population Genetics of Nosema apis and Nosema ceranae: One Host (Apis mellifera) and Two Different Histories.
abstract: Two microsporidians are known to infect honey bees: Nosema apis and Nosema ceranae. Whereas population genetics data for the latter have been released in the last few years, such information is still missing for N. apis. Here we analyze the patterns of nucleotide polymorphism at three single-copy loci (PTP2, PTP3 and RPB1) in a collection of Apis mellifera isolates from all over the world, naturally infected either with N. apis (N = 22) or N. ceranae (N = 23), to provide new insights into the genetic diversity, demography and evolution of N. apis, as well as to compare them with evidence from N. ceranae. Neutral variation in N. apis and N. ceranae is of the order of 1%. This amount of diversity suggests that there is no substantial differentiation between the genetic content of the two nuclei present in these parasites, and evidence for genetic recombination provides a putative mechanism for the flow of genetic information between chromosomes. The analysis of the frequency spectrum of neutral variants reveals a significant surplus of low frequency variants, particularly in N. ceranae, and suggests that the populations of the two pathogens are not in mutation-drift equilibrium and that they have experienced a population expansion. Most of the variation in both species occurs within honey bee colonies (between 62%-90% of the total genetic variance), although in N. apis there is evidence for differentiation between parasites isolated from distinct A. mellifera lineages (20%-34% of the total variance), specifically between those collected from lineages A and C (or M). This scenario is consistent with a long-term host-parasite relationship and contrasts with the lack of differentiation observed among host-lineages in N. ceranae (< 4% of the variance), which suggests that the spread of this emergent pathogen throughout the A. mellifera worldwide population is a recent event.
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, 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, Santiago de Compostela, Galicia, Spain.
authors.forename: Xulio
authors.initials: X
authors.lastname: Maside
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain.|Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain.|Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain.
authors.forename: Tamara
authors.initials: T
authors.lastname: Gómez-Moracho
authors.affiliation: Departamento de Zoología y Antropología Física, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Jara
authors.affiliation: Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain.|Instituto de Recursos Humanos para la Ciencia y la Tecnología (INCRECYT-FEDER), Fundación Parque Científico y Tecnológico de Albacete, Albacete, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Martín-Hernández
authors.affiliation: Departamento de Zoología y Antropología Física, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: De la Rúa
authors.affiliation: Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Higes
authors.affiliation: Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain.|Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Bartolomé
mesh_terms: D000818:Animals; D001516:Bees / Q000382:microbiology*; D056426:Genetic Loci; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000235:genetics*; D008540:Meiosis; D016818:Nosema / Q000166:cytology / Q000235:genetics*; D009711:Nucleotides / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics
chemical_list: D009711:Nucleotides