title: Chromosomal polymorphism in the yeast species Debaryomyces hansenii.
abstract: Pulse field gel electrophoresis karyotypes of 41 strains of the genus Debaryomyces, including 35 strains confirmed as D. hansenii species by D1/D2 ribosomal DNA sequence analysis, were performed. Electrophoretic karyotypes of the 41 strains exhibited 4 to 10 chromosomal bands ranging between 0.7 Mb and 4.2 Mb. Among D. hansenii species, the patterns of strains obtained from the CBS collection and cheese isolates differed strongly from D. hansenii var. hansenii CBS767T. Both D. hansenii var. hansenii and D. hansenii var. fabryii showed chromosome length polymorphism. Electrophoretic karyotypes of the D. hansenii strains were analyzed by Southern hybridization with various species-specific probes isolated from D. hansenii var. hansenii CBS767T. Repeated sequences including the F01pro, M18pro, the Ty1-copia retrotransposon Tdh5 and hypothetical telomeric sequence hybridized to several chromosomal bands, while a D1/D2 probe derived from the large ribosomal sub-unit hybridized only to the largest chromosome. Unique probes such as those hybridizing to actin ACT1, glycerol-3-phosphate dehydrogenase GPD1 and beta-glucosidase LAC4 encoding genes were assigned to specific chromosomal bands of D. hansenii var. hansenii CBS767T. These probes failed to hybridize to D. hansenii var. fabryii strongly suggesting that strains of this variety actually represent a different taxon.
authors.affiliation: Laboratoire de Génétique Moléculaire et Cellulaire INRA UMR216, CNRS URA 1925, Collection de Levures d'Intérêt Biotechnologique, Institut National Agronomique Paris-Grignon, 78850 Thiverval-Grignon, France.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Corredor
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Davila
authors.forename: Serge
authors.initials: S
authors.lastname: Casarégola
authors.forename: Claude
authors.initials: C
authors.lastname: Gaillardin
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D015825:Chromosomes, Fungal / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D016521:Electrophoresis, Gel, Pulsed-Field; D007621:Karyotyping; D011110:Polymorphism, Genetic; D004718:Saccharomycetales / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D013045:Species Specificity
chemical_list: D004271:DNA, Fungal