title: Chromosomal localisation of five genes in Perkinsus olseni (Phylum Perkinsozoa).
abstract: The molecular karyotype of Perkinsus olseni, a pathogenic protist that infects the clam Ruditapes decussatus, comprises nine chromosomes, ranging in size from 0.15 Mb to 6.5 Mb, representing a haploid genome of about 28 Mb. In order to establish chromosome specific markers, PCR-amplified DNA sequences belonging to five conserved genes (18S rRNA, actin type I, hsp90, β-tubulin and calmodulin) were hybridised to chromosomal bands separated by pulsed-field gel electrophoresis. Three of those probes (actin type I, hsp90 and calmodulin) hybridised to only one chromosome and the remaining two (18S rRNA and β-tubulin) hybridised to two chromosomes. In the first place, the hybridisation pattern obtained serves to dispel any doubt about the nuclear location of the smallest chromosome observed in the molecular karyotype of Perkinsus olseni. Additionally, it will be a reference for further analysis of karyotype polymorphisms in the genus Perkinsus.
authors.affiliation: Molecular Genetic Laboratory, Institute of Biomedical Sciences Abel Salazar, University of Porto, P-4099-003 Porto, Portugal.
authors.forename: Américo
authors.initials: A
authors.lastname: Marques
authors.forename: Joana
authors.initials: J
authors.lastname: Tato-Costa
authors.forename: Carlos
authors.initials: C
authors.lastname: Conde
authors.forename: Carlos
authors.initials: C
authors.lastname: Azevedo
authors.forename: M Leonor
authors.initials: ML
authors.lastname: Teles-Grilo
mesh_terms: D056893:Alveolata / Q000235:genetics; D002874:Chromosome Mapping; D002875:Chromosomes; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D017125:Genes, Protozoan; D005819:Genetic Markers; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D005819:Genetic Markers