title: Sex chromosome positions in human interphase nuclei as studied by in situ hybridization with chromosome specific DNA probes.
abstract: Two cloned repetitive DNA probes, pXBR and CY1, which bind preferentially to specific regions of the human X and Y chromosome, respectively, were used to study the distribution of the sex chromosomes in human lymphocyte nuclei by in situ hybridization experiments. Our data indicate a large variability of the distances between the sex chromosomes in male and female interphase nuclei. However, the mean distance observed between the X and Y chromosome was significantly smaller than the mean distance observed between the two X-chromosomes. The distribution of distances determined experimentally is compared with three model distributions of distances, and the question of a non-random distribution of sex chromosomes is discussed. Mathematical details of these model distributions are provided in an Appendix to this paper. In the case of a human translocation chromosome (Xqter----Xp22.2::Yq11----Yqter) contained in the Chinese hamster X human hybrid cell line 445 X 393, the binding sites of pXBR and CY1 were found close to each other in most interphase nuclei. These data demonstrate the potential use of chromosome-specific repetitive DNA probes to study the problem of interphase chromosome topography.
mesh_terms: D002467:Cell Nucleus / Q000648:ultrastructure*; D002503:Centromere; D005260:Female; D006801:Humans; D007399:Interphase; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D009693:Nucleic Acid Hybridization; D012730:Sex Chromosomes / Q000648:ultrastructure*