Figure 5. Nascent acini and their absence with aging. (A) A 3-D reconstruction of the 5 month old meibomian gland and an orthoslice taken at the region of interest: the transition between duct and acini (yellow arrowhead). (B) An acinus with a significant CK6+ component (C) also exhibits localized proliferation in the same region, according to Ki67 staining (D) and the resulting overlay (E). (F) The 3-D reconstruction of a 2 year meibomian gland with ductal truncation was evaluated at the same transitional region between duct and multiple acini (G - red arrowheads) and no prominent CK6 (H) or (I) Ki67 staining was evident when overlaying the sequential immunostains (J), suggesting a loss of proliferation in these zones.