Expression of the cyclin-dependent kinase inhibitors (CKIs) has been linked to the inhibition of cellular proliferation and the induction of differentiation. Based on structure function analysis, two distinct families of CDKIs, the INK4 and the Cip/ @entity69061 family have been identified. The INK4 family member @entity11754 (Ink4), and the Cip/ @entity69061 protein @entity5447 ( @entity5447 ) have been implicated in normal development of the CNS and cerebellum. Recent studies have suggested a functional inter-dependence between the CKI and the abundance of @entity12003 in orchestrating @entity2140 -induced cellular proliferation. The neonatal @entity35 cerebellum undergoes proliferative growth and differentiation, localized to distinct topographical regions and cell types. The cell type and the temporal profile of CKI expression during postnatal cerebellar development had not been described. The current studies determined the specific cerebellar cell types in which the CKIs were expressed during post natal development by co-staining for cell-type specific markers. @entity11754 ( @entity11754 ) and @entity5447 ( @entity5447 ) immunostaining was identified in both neurons and glial cells, increasing progressively between postnatal days 6 to 13 into adulthood. By contrast, neuronal and glial cell @entity7504 ( @entity9533 ) staining was prominent at days 6-11 and decreased thereafter. @entity12003 was expressed in the proliferating external granular cells, with occassional staining in the molecular, and internal granular layers. Dual immunostaining demonstrated @entity12003 within cells expressing CKI ( @entity11754 ( @entity11754 ), @entity7504 ( @entity9533 ), @entity5447 ( @entity5447 )). Cerebellar cellular growth arrest, induced by @entity7493 , inhibited @entity12003 protein levels without affecting CKI immunostaining suggesting CKI do not mediate the developmental arrest. These results demonstrate that the CKIs are induced by differentiation cues in specific cell types with distinct kinetics in the developing cerebellum in vivo.

Immunohistochemical examination of the INK4 and Cip inhibitors in the XXXX neonatal cerebellum: cellular localization and the impact of @entity7493 .

@entity7493 :: ('MESH:D011502', 'Disease') :: ['protein-calorie malnutrition'] @entity7504 :: ('24525(Tax:10116)', 'Gene') :: ['p21'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity11754 :: ('25163(Tax:10116)', 'Gene') :: ['p16', 'Ink4a'] @entity69061 :: ('81823(Tax:10116)', 'Gene') :: ['Kip'] @entity12003 :: ('58919(Tax:10116)', 'Gene') :: ['cyclin D1', 'Cyclin D1'] @entity9533 :: ('114851(Tax:10116)', 'Gene') :: ['Cip1'] @entity2140 :: ('79215(Tax:10116)', 'Gene') :: ['growth factor'] @entity5447 :: ('83571(Tax:10116)', 'Gene') :: ['Kip1', 'p27']
@entity35 :: (10116,Species) :: ['rat']
