title: Isolation of a cancer-associated microchromosome in the sperm-dependent parthenogen Poecilia formosa.
abstract: In the asexual all-female fish species Poecilia formosa, the Amazon molly, supernumerary chromosomes have frequently been found in both laboratory-reared and wild-caught individuals. While wild-caught individuals with B chromosomes are phenotypically indifferent from conspecifics, individuals carrying B chromosomes from recent introgression events in the laboratory show phenotypic changes. Former analyses showed that the expression of a pigment cell locus is associated with the presence of these B chromosomes. In addition, they contain a so far unidentified locus that confers a higher susceptibility to tumor formation in the presence of pigmentation pattern. Isolation by microdissection and hybridization to metaphase chromosomes revealed that they contain one or several sequences with similarity to a highly repetitive pericentromeric and subtelomeric sequence in A chromosomes. Isolation of one particular sequence by AFLP showed that the B chromosomes contain at least 1 copy of an A-chromosomal region which is highly conserved in the whole genus Poecilia, i.e. more than 5 million years old. We propose it to be a single copy sequence.
authors.affiliation: Physiological Chemistry I, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: D K
authors.initials: DK
authors.lastname: Lamatsch
authors.forename: V
authors.initials: V
authors.lastname: Trifonov
authors.forename: S
authors.initials: S
authors.lastname: Schories
authors.forename: J T
authors.initials: JT
authors.lastname: Epplen
authors.forename: M
authors.initials: M
authors.lastname: Schmid
authors.forename: M
authors.initials: M
authors.lastname: Schartl
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002875:Chromosomes / Q000235:genetics*; D016172:DNA Fingerprinting; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D056426:Genetic Loci / Q000235:genetics; D005838:Genotype; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008297:Male; D008547:Melanophores / Q000378:metabolism; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000235:genetics*; D010312:Parthenogenesis; D010641:Phenotype; D011036:Poecilia / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013094:Spermatozoa / Q000378:metabolism*