title: Cell synchronization and dynamic G-banding of equine chromosomes by bromodeoxyuridine.
abstract: Both dynamic G-banding and cell synchronization produced by bromodeoxyuridine (BrdU), were applied to equine chromosomes. BrdU incorporated during the first half of the S-phase is taken up into the R-bands that are early replicating. These bands, which have incorporated BrdU, cannot contract as usual and remain elongated; only the other regions of the chromosome, i.e., the G-bands, contract normally and are sharply defined. BrdU also can be used for cell synchronization. The addition of BrdU in a high concentration, 15 hours before harvest, and its removal 11 hours later, has two effects: initially the BrdU is incorporated during the first part of the S-phase and then it blocks the cells at mid-S-phase. Within the cell cycle, mid-S-phase appears to be the most vulnerable time to various blocking agents. To differentiate the regions of BrdU incorporation from those that have not been substituted, the fluorescence-photolysis-Giemsa (FPG) technique was applied as modified for horse chromosomes. This dynamic technique, which produces many prometaphase and prophase chromosomes showing very sharp G-bands, is certain to enhance the accuracy of cytogenetic analysis and aid in the standardization of equine chromosomes.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002478:Cells, Cultured; D002871:Chromosome Banding; D002875:Chromosomes / Q000187:drug effects / Q000648:ultrastructure*; D006736:Horses / Q000235:genetics*; D007399:Interphase / Q000187:drug effects; D007621:Karyotyping; D008297:Male
chemical_list: D001973:Bromodeoxyuridine