2008 年 18 巻 1 号 p. 57-64
A new concept for the genome structure of mammalian cells is introduced with a model (A fractal structure model) constructed based on observations that have been reported. Briefly, the DNA structure is a self-similar fractal with a unit of opposite-handed twin circles. The DNA in human diploid cells is constructed with six hierarchies whose sizes are 325, 324, 323, 322, 321, and 320 with a unit of 200 DNA base pairs, corresponding to a genome, a chromosome, a chromosome band, a replicon, a rosette loop (a gene), and a nucleosome, respectively. This model may solve the questions why the band number of chromosomes decreases in M phase, why R-bands are replicated earlier than G-bands, why the telomere repeat is required for cells, and why the homologous chromosome can cynapsize in meiosis.