[Model of chromonema packing in the mitotic chromosome]

Based on available data, a model of packing of a chromonemata in mitotic chromosomes is presented (fig. 1). The model reflects three well established facts: 1) chromosomes are uninemic, i.e. each chromonema consists of a single DNA molecule (or a single chain of linked DNA molecules), whose ends are located in telomeres; 2) a proteinaceous fibre is a structural basis of a chromatid; the fibre is folded, its ends are located near a centromere; 3) a chromonema makes a spiral in the chromatid. The model reveals half-chromatid structure of mitiotic chromosomes and may describe morphological changes of chromosomes induced by substances affecting the states of chromonemata or fibres.