title: Genetics and electrophoretic karyotyping of wild-type and astaxanthin mutant strains of Phaffia rhodozyma.
abstract: In this work we establish the chromosomal composition of a wild-type, one astaxanthin and two beta-carotene overproducer strains of the red yeast Phaffia rhodozyma. The method used has been pulsed field gel electrophoresis, which has determined 9 DNA chromosomal bands in the yeast genome. The two largest bands are triplets and two other bands, VI and VIII, seem to be doublets. The size of the chromosomal bands varies between 0.35 and 2.5 Mb, suggesting a genome size of 25 Mb. The technique used, complemented with hybridization assays using specific DNA probes, provides direct information about the genomic organization of P. rhodozyma. We have also cloned and located in chromosomal bands different DNA sequences that code for the translation elongation factor 1 alpha (ef-1 alpha), a 7.6 kb BamHI fragment of repetitive DNA (possibly rDNA) and a randomly chosen fragment (named locus R2). Additionally, we have detected a chromosomal length polymorphism between wild-type strains and mutant strains affecting carotenogenesis obtained in our laboratory.
authors.affiliation: Laboratorio de Genética, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
authors.forename: V
authors.initials: V
authors.lastname: Cifuentes
authors.forename: G
authors.initials: G
authors.lastname: Hermosilla
authors.forename: C
authors.initials: C
authors.lastname: Martínez
authors.forename: R
authors.initials: R
authors.lastname: León
authors.forename: G
authors.initials: G
authors.lastname: Pincheira
authors.forename: A
authors.initials: A
authors.lastname: Jiménez
mesh_terms: D001487:Basidiomycota / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D015342:DNA Probes / Q000235:genetics; D004271:DNA, Fungal / Q000032:analysis*; D016521:Electrophoresis, Gel, Pulsed-Field; D016681:Genome, Fungal; D007621:Karyotyping; D008769:Methylnitronitrosoguanidine; D016296:Mutagenesis; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism
chemical_list: D015342:DNA Probes; D004271:DNA, Fungal; D024341:Xanthophylls; D019207:beta Carotene; D008769:Methylnitronitrosoguanidine; C005948:astaxanthine