[Formation of spherical colonies as a property of stem cells].

The report deals with the ability of embryonic cells harvested from the nervous, hematopoietic and epithelial-muscular human tissues to form spheres during in vitro culturing. Judging from their own data and those reported elsewhere, the authors have hypothesized that formation of spherical colonies in vitro is a common feature of stem cells of various origin and varying degree of maturation. Probably, the formation of spheres provides for development of stem cells according to the locations and their inner temporal programs, which are specific and particular for every type of cells.