Figure 1

Cyclin D1-induced senescence occurs over several weeks. A) Ki67 staining of Irbp-Cyclin D1 pineal sections at the indicated ages (left); immunoflourescence staining for Histone 3 trimethylated at Lysine 9 (H3K9me3) in pineal sections at the indicated ages (middle), with corresponding DAPI staining (right). B) Quantitation of Ki67-positive cells as percent of total pineal cells at indicated ages. C) Immunostaining for Dec1, DcR2, and p15Ink4b, in Irbp-Cyclin D1 pineal glands at the indicated ages.