title: New insights on the genetic diversity of the honeybee parasite Nosema ceranae based on multilocus sequence analysis.
abstract: The microsporidian parasite Nosema ceranae is a common pathogen of the Western honeybee (Apis mellifera) whose variable virulence could be related to its genetic polymorphism and/or its polyphenism responding to environmental cues. Since the genotyping of N. ceranae based on unique marker sequences had been unsuccessful, we tested whether a multilocus approach, assessing the diversity of ten genetic markers – encoding nine proteins and the small ribosomal RNA subunit – allowed the discrimination between N. ceranae variants isolated from single A. mellifera individuals in four distant locations. High nucleotide diversity and allele content were observed for all genes. Most importantly, the diversity was mainly present within parasite populations isolated from single honeybee individuals. In contrast the absence of isolate differentiation precluded any taxa discrimination, even through a multilocus approach, but suggested that similar populations of parasites seem to infect honeybees in distant locations. As statistical evolutionary analyses showed that the allele frequency is under selective pressure, we discuss the origin and consequences of N. ceranae heterozygosity in a single host and lack of population divergence in the context of the parasite natural and evolutionary history.
authors.affiliation: Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes: Génome et Environnement, BP 10448, 63000 Clermont-Ferrand, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Roudel
authors.forename: Julie
authors.initials: J
authors.lastname: Aufauvre
authors.forename: Bruno
authors.initials: B
authors.lastname: Corbara
authors.forename: Frederic
authors.initials: F
authors.lastname: Delbac
authors.forename: Nicolas
authors.initials: N
authors.lastname: Blot
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001483:Base Sequence; D001516:Bees / Q000382:microbiology*; D005075:Biological Evolution; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D015810:Linkage Disequilibrium; D058885:Multilocus Sequence Typing / Q000662:veterinary*; D016818:Nosema / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic; D016415:Sequence Alignment / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005656:Fungal Proteins; D005819:Genetic Markers