Somatic instability of a Drosophila chromosome.
A mitotically unstable chromosome, detectable because of mosaic expression of marker genes, was generated by X-ray mutagenesis in Drosophila. Nondisjunction of this chromosome is evident in mitotic chromosome preparations, and premature sister chromatid separation is frequent. The mosaic phenotype is modified by genetic elements that are thought to alter chromatin structure. We hypothesize that the mitotic defects result from a breakpoint deep in the pericentric heterochromatin, within or very near to the DNA sequences essential for centromere function. This unique chromosome may provide a tool for the genetic and molecular dissection of a higher eukaryotic centromere.
Wines
D R
DR
Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Henikoff
S
S
D000818:Animals; D002503:Centromere; D002875:Chromosomes / Q000528:radiation effects; D003433:Crosses, Genetic; D004330:Drosophila / Q000235:genetics*; D005260:Female; D005799:Genes, Dominant; D005819:Genetic Markers; D007150:Immunohistochemistry; D007621:Karyotyping; D008297:Male; D008938:Mitosis; D005810:Multigene Family; D016296:Mutagenesis; D009630:Nondisjunction, Genetic; D009693:Nucleic Acid Hybridization; D014178:Translocation, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D005819:Genetic Markers; D001616:beta-Galactosidase