[DNA replication in cultured amniotic fluid cells].

A correlation was studied between replication and characteristics of the synthesis of DNA cells in amniotic fluid under in-vitro cultivation. Radioautography of DNA molecules was used to show that in the primary cultures of epithelium- and fibroblast-like cells of amniotic fluid, DNA replication proceeds at a lower rate as compared to that in diploid cells of the fetus skin. The DNA replication rate in the passaged cells of amniotic fluid does not differ from that seen in controls. The cultivated fibroblasts obtained from amniotic fluid of the fetus with anencephalia manifested a significant increase in the DNA replication rate. The size and number of the replication units do not differ as shown by the examination of all cell types. The data obtained suggest a correlation between the diminution of the DNA molecule replication rate and the decreased growth tendency under in-vitro cultivation of human amniotic fluid cells. The reasons are discussed which are likely to provoke the decreased rate of the replication fork movement in the primary cell cultures of human amniotic fluid.