title: Virulence and polar tube protein genetic diversity of Nosema ceranae (Microsporidia) field isolates from Northern and Southern Europe in honeybees (Apis mellifera iberiensis).
abstract: Infection of honeybees by the microsporidian Nosema ceranae is considered to be one of the factors underlying the increased colony losses and decreased honey production seen in recent years. However, these effects appear to differ in function of the climatic zone, the distinct beekeeping practices and the honeybee species employed. Here, we compared the response of Apis mellifera iberiensis worker bees to experimental infection with field isolates of N. ceranae from an Oceanic climate zone in Northern Europe (Netherlands) and from a Mediterranean region of Southern Europe (Spain). We found a notable but non-significant trend (P = 0.097) towards higher honeybee survival for bees infected with N. ceranae from the Netherlands, although no differences were found between the two isolates in terms of anatomopathological lesions in infected ventricular cells or the morphology of the mature and immature stages of the parasite. In addition, the population genetic survey of the N. ceranae PTP3 locus revealed high levels of genetic diversity within each isolate, evidence for meiotic recombination, and no signs of differentiation between the Dutch and Spanish populations. A cross-infection study is needed to further explore the differences in virulence observed between the two N. ceranae populations in field conditions.
authors.affiliation: Nederlands Centrum Bijenonderzoek (NCB), Tersoal, Netherlands.
authors.forename: Romee
authors.initials: R
authors.lastname: Van der Zee
authors.forename: Tamara
authors.initials: T
authors.lastname: Gómez-Moracho
authors.forename: Lennard
authors.initials: L
authors.lastname: Pisa
authors.forename: Soledad
authors.initials: S
authors.lastname: Sagastume
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Palencia
authors.forename: Xulio
authors.initials: X
authors.lastname: Maside
authors.forename: Carolina
authors.initials: C
authors.lastname: Bartolomé
authors.forename: Raquel
authors.initials: R
authors.lastname: Martín-Hernández
authors.forename: Mariano
authors.initials: M
authors.lastname: Higes
mesh_terms: D000818:Animals; D001516:Bees / Q000382:microbiology* / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009426:Netherlands; D016818:Nosema / Q000145:classification* / Q000235:genetics / Q000254:growth & development*; D017422:Sequence Analysis, DNA; D013030:Spain; D016019:Survival Analysis
chemical_list: D005656:Fungal Proteins