Expression domains suggest cell-cycle independent roles of growth-arrest molecules in the adult brain of the medaka, Oryzias latipes.
Teleost fish are unique for their enormous potential to produce new neurons in the adult brain. Nevertheless, the regulation of this adult neurogenesis remains to be characterized. Does it resort to the same molecular mechanisms as those at play in embryonic development? Here, we analyse the expression of the neurogenic gene Ol-DeltaA in the brain of medaka (Oryzias latipes) embryos and adults. To determine the relationships between neurogenic and growth-arrest genes in the adult brain, we compare the expression domains of Ol-DeltaA with those of Ol-KIP and Ol-Gadd45gamma, two well-characterized genes involved in cell-cycle arrest and growth inhibition. While it is widely assumed that genes controlling cell-cycle exit show restricted expression domains next to proliferating cells (in the sites of prospective cell differentiation), we observe highly particular expression domains of Ol-KIP and Ol-Gadd45gamma not associated to proliferating areas of the adult brain, suggesting locally different and cell-cycle independent roles of these molecules in the adult brain.
Candal
Eva
E
JE INRA U1126, INRA/CNRS Group, UPR 2197 DEPSN, CNRS, Institut de Neurosciences A. Fessard, Gif-sur-Yvette, France. ecandal@usc.es
Nguyen
Vân
V
Joly
Jean-Stéphane
JS
Bourrat
Franck
F
D000818:Animals; D001921:Brain / Q000196:embryology* / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D017403:In Situ Hybridization / Q000379:methods; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009990:Oryzias; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D000097642:GADD45 Proteins
D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D029941:Fish Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D000097642:GADD45 Proteins; C447319:KIP protein, Oryzias latipes