Modification of the cell cycle of limb bud mesenchyme during in vitro cartilage differentiation.
A consistent chondrogenesis takes place in micro high-density cultures derived from limb mesenchymal cells of chick embryos of stages 23-24. Flow-cytometric measurements of DNA content showed that cells in the phase of G1 or G0 made up 51% of the dispersed cell suspensions. The proportion of these cells increased to 71% by the onset of cartilage differentiation in day-2 cultures. This ratio was 84% when the voluminous matrix formation began on the 4th day of culturing. Thereafter, it increased to 90% by the 6th day, and to 93% by the 14th day. The results suggest that cartilage differentiates from G0 mesenchymal cells of the limb. In our measurements, however, the G0 phase includes all non-proliferative cell population which have identical DNA content with G1 cells. Therefore, the G0 phase contains also an increasing number of chondroblasts and chondrocytes as the chondrogenesis proceeds.
D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000196:embryology*; D002453:Cell Cycle; D002454:Cell Differentiation; D002478:Cells, Cultured; D002642:Chick Embryo; D004247:DNA / Q000378:metabolism; D005121:Extremities / Q000196:embryology; D007399:Interphase; D008648:Mesoderm / Q000166:cytology*; D013997:Time Factors
D004247:DNA