Cell kinetics in the sebaceous glands of the mouse. I. The glands in resting skin.

Abstract

ABSTRACTCell proliferation, differentiation and migration have been studied in the sebaceous glands of DBA‐2 mice in the resting (telogen) phase of hair growth. Cells labelled by a single injection of tritiated thymidine start to leave the glands of adult male mice 5 days later. About 80% of the proliferative cells in the basal layer have a cell cycle time of 40 hr or less. In 18% of the proliferative cells G1 is at least 4 days long and 16% have a G2 phase longer than 17 hr. The S phase is about 7.5 hr long and cells spend at least 21 hr in the basal layer before migrating into the differentiating cell region. The glands of mature female and immature mice are smaller than those of the mature male. They have fewer, smaller cells and a much lower labelling index.