Deoxyribonucleic Acid Content of Basal Cells of Mouse Epidermis

Abstract

STUDIES on mouse-ear and body-skin epidermis have led Gelfant^1,2 to the conclusion that there are two distinct populations of epidermal cells, one with a G₂ period of a few hours, the other with a G₂ period as long as five days. Bullough³ has commented on the work of Gelfant and stated that his results are statistically inadequate. In view of the general uniformity in length of the G₂ period in mammalian cells studied so far⁴ of approximately 2–4 h, the existence of a population of cells with an unusually long G₂ period is of some importance. It seemed worth while, therefore, to determine the distribution of DNA levels in epidermal cells, using a densitometric method, since a pronounced peak would be found at the tetraploid level if a sizeable population of cells were in the G₂ state.