| Affiliation: | (1) Laboratory of Cytogenetics, Division of Bioscience, Graduate School of Environmental Earth Science, Hokkaido University, North 10 West 8, Kita-ku, Sapporo 060-0810, Japan;(2) Laboratory of Animal Cytogenetics, Center for Advanced Science and Technology, Hokkaido University, North 10 West 8, Kita-ku, Sapporo 060-0810, Japan |
| Abstract: | A novel family of repetitive DNA sequences that are components of constitutive heterochromatin were cloned from BglI-digested genomic DNA of the Chinese soft-shelled turtle (Pelodiscus sinensis, Trionychidae), and characterized by filter hybridization and chromosome in-situ hybridization. The BglI-family of repetitive sequences were classified into four types by their genome organization and chromosomal distribution as follows: the repeated sequences located on (1) two pairs of microchromosomes, (2) four pairs of microchromosomes,(3) about half the number of microchromosomes and (4) the interstitial region of the short arm of chromosome 2. The presence of microchromosome-specific repetitive sequences has also been reported in the Struthioniformes and Galliformes, suggesting that turtle chromosomes retain some similarity to the chromosome structure as well as the karyotypes of avian species |
