PCNA positivity in the telencephalic matrix areas in the adult of a lizard, Podarcis sicula.

In the present paper a reappraisal is made of the persistence and size of telencephalic matrix areas in normal adult specimens of a lizard, Podarcis sicula, using a recent in situ marker of cells in the S phase, the Proliferating Cell Nuclear Antigen (PCNA), belonging to the cyclin family, proteins that regulate the cell cycle and that can be immunocytochemically evidenced using monoclonal antibodies. Only a small number of positive PCNA elements, randomly arranged in the dorsal (medial and lateral) matrix areas, were found in the telencephalic ependymal tissue. These elements were found in larger numbers and distributed more uniformly in the ventral matrix areas, both opposite the ventricular lumen and outside the ependyma.