The cyclin-dependent kinase (Cdk) inhibitor p27Kip1 contributes to the timing of cell cycle withdrawal during development and, consequently, in organogenesis. Within the retina, this effector protein is up-regulated during the birth of neuronal and glial cells [Dev. Biol. (2000) 299]. However, its expression within the retinal pigment epithelium (RPE), a supporting cell layer that is essential for neural retina development and function, has not previously been reported. We show that p27Kip1 protein expression in the RPE occurs in two phases: an up-regulation during mid-to late embryonic stages and a down-regulation during the subsequent postnatal period. In the early phase of up-regulation, an inverse relationship is seen between expression of p27Kip1 and PCNA, an indicator of cycling cells. During both up-and down-regulation, the change in spatial pattern of expression proceeds in a central to peripheral manner, with p27Kip1 up-regulation paralleling retinal maturation. These data suggest that this cell cycle regulator may be an important factor controlling the timing of RPE cell cycle withdrawal.
Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-15327 |
Date | 01 October 2003 |
Creators | Defoe, Dennis M., Levine, Edward M. |
Publisher | Digital Commons @ East Tennessee State University |
Source Sets | East Tennessee State University |
Detected Language | English |
Type | text |
Source | ETSU Faculty Works |
Page generated in 0.044 seconds