title: InterB multigenic family, a gene repertoire associated with subterminal chromosome regions of Encephalitozoon cuniculi and conserved in several human-infecting microsporidian species.
abstract: Microsporidia are fungi-related obligate intracellular parasites that infect numerous animals, including man. Encephalitozoon cuniculi harbours a very small genome (2.9 Mbp) with about 2,000 coding sequences (CDSs). Most repeated CDSs are of unknown function and are distributed in subterminal regions that mark the transitions between subtelomeric rDNA units and chromosome cores. A potential multigenic family (interB) encoding proteins within a size range of 579-641 aa was investigated by PCR and RT-PCR. Thirty members were finally assigned to the E. cuniculi interB family and a predominant interB transcript was found to originate from a newly identified gene on chromosome III. Microsporidian species from eight different genera infecting insects, fishes or mammals, were tested for a possible intra-phylum conservation of interB genes. Only representatives of the Encephalitozoon, Vittaforma and Brachiola genera, differing in host range but all able to invade humans, were positive. Molecular karyotyping of Brachiola algerae showed a complex set of chromosome bands, providing a haploid genome size estimate of 15-20 Mbp. In spite of this large difference in genome complexity, B. algerae and E. cuniculi shared some similar interB gene copies and a common location of interB genes in near-rDNA subterminal regions.
authors.affiliation: Equipe Parasitologie Moléculaire et Cellulaire, Laboratoire de Biologie des Protistes, UMR CNRS 6023, Bâtiment Biologie A, Université Blaise Pascal, 63177 Aubière cedex, France.
authors.forename: Ndongo
authors.initials: N
authors.lastname: Dia
authors.forename: Laurence
authors.initials: L
authors.lastname: Lavie
authors.forename: Guy
authors.initials: G
authors.lastname: Méténier
authors.forename: Bhen S
authors.initials: BS
authors.lastname: Toguebaye
authors.forename: Christian P
authors.initials: CP
authors.lastname: Vivarès
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Cornillot
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015825:Chromosomes, Fungal / Q000235:genetics*; D019295:Computational Biology; D017124:Conserved Sequence; D004285:Dogs; D009670:Encephalitozoon cuniculi / Q000235:genetics* / Q000472:pathogenicity*; D016890:Encephalitozoonosis / Q000382:microbiology; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D013045:Species Specificity; D021863:Vittaforma / Q000235:genetics
chemical_list: D005656:Fungal Proteins