title: Chromosome replication in fibroblasts of the Syrian hamster (Mesocricetus auratus).
abstract: The BrdU/Hoechst 33258/Giemsa method for sub-dividing S-phase in asynchronous cell populations has been re-evaluated and modified to give better definition and more even distribution of sub-phases. A reference pattern of early-replicating euchromatic bands is given for all chromosomes at Sk2 in primary cultures of skin fibroblasts. The overall band patterns at each sub-phase have allowed more objective definitions of "early" and "late" replication for these cells, and show that in both classes of chromatin light G-bands preceed dark G-bands. Asynchrony between homologous bands is observed at all stages of S, albeit with a variable frequency. The observed in vitro replication patterns and programme for the chromosomes of skin fibroblasts does not appear to be affected by the age or sex of the source.
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002478:Cells, Cultured; D002871:Chromosome Banding; D002875:Chromosomes / Q000648:ultrastructure*; D006224:Cricetinae / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D008647:Mesocricetus / Q000235:genetics*; D012867:Skin / Q000648:ultrastructure