title: Spatial and temporal expression patterns of the cyclin-dependent kinase (CDK) inhibitors p27Kip1 and p57Kip2 during mouse development.
abstract: The cyclin-dependent kinase (CDK) inhibitors p27Kip1 and p57Kip2 are thought to regulate progression of the cell cycle. We have previously shown that the phenotypes of p27-/- mice are substantially different from those of p57-/- mice, suggesting that spatial and temporal expression patterns of p27Kip1 and p57Kip2 might be distinct. In this study, the roles of p27Kip1 and p57Kip2 in development were examined by characterizing their expression patterns during mouse embryogenesis by immunohistochemical analysis. Whereas certain organs and tissues (brain, lens, ganglion, lung, heart, liver, skin and kidney) expressed both proteins, others expressed only p27Kip1 (thymus, spleen, retina, testis and ovary) or only p57Kip2 (gut, palate, pancreas, cartilage and skeletal muscle). In addition, some organs expressed both p27Kip1 and p57Kip2 but showed mutually exclusive patterns of distribution among tissues. Thus, in the adrenal gland, p57Kip2 was expressed in the cortex but not in the medulla, whereas p27Kip1 was expressed in the medulla but not in the cortex. Whereas the expression of p57Kip2 in most tissues was restricted to embryogenesis, expression of p27Kip1 in many tissues was maintained in adult animals. Double-label immunofluorescence staining with either anti-p27Kip1 or anti-p57Kip2 and anti-BrdU revealed that the expression of p27Kip1 and p57Kip2 was inversely correlated with cell proliferation, suggesting that p27Kip1 and p57Kip2 are expressed exclusively in postmitotic cells. These complex spatial and temporal patterns of expression are consistent with the phenotypes of mice deficient in p27Kip1 or p57Kip2, and they suggest that these proteins might play important roles in tissue development.
authors.affiliation: Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nagahama
authors.forename: S
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: M
authors.initials: M
authors.lastname: Nagata
authors.forename: K
authors.initials: K
authors.lastname: Tomita
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
mesh_terms: D000302:Adrenal Cortex / Q000737:chemistry; D000313:Adrenal Medulla / Q000737:chemistry; D000375:Aging; D000818:Animals; D000918:Antibody Specificity; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002455:Cell Division; D050760:Cyclin-Dependent Kinase Inhibitor p27; D050761:Cyclin-Dependent Kinase Inhibitor p57; D005314:Embryonic and Fetal Development; D005455:Fluorescent Antibody Technique; D006128:Growth; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000032:analysis* / Q000172:deficiency / Q000502:physiology; D008938:Mitosis; D009687:Nuclear Proteins / Q000032:analysis* / Q000172:deficiency / Q000502:physiology; D009928:Organ Specificity; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins
chemical_list: C493961:Cdkn1b protein, mouse; C493965:Cdkn1c protein, mouse; D018797:Cell Cycle Proteins; D050761:Cyclin-Dependent Kinase Inhibitor p57; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27