The effect of added H1 histone and polylysine on DNA synthesis and cell division of cultured mammalian cells.

Addition of H1 histone or polylysine (10 microgram/ml) to cultured Friend erythroleukemia cells or to two mouse lymphoma cell lines (el-4 and S-49) increased levels of cell division in these cultures. There is a stimulation of incorporation of labeled thymidine into DNA in cultures containing H1 histone and polylysine. DNA fiber autoradiographic experiments revealed that replicon size is decreased in the cells cultured with H1 histone and polylysine at later periods of culture.