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[P1.20]: Developmental relocation of dentate stem cells to the subgranular zone depends on a transient neurogenic niche
Author(s) -
Li G.,
Kataoka H.,
Coughlin S.R.,
Pleasure S.J.
Publication year - 2008
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2008.09.070
Subject(s) - pleasure , subgranular zone , computer science , psychology , neuroscience , biology , stem cell , subventricular zone , progenitor cell , genetics
Adult neurogenesis in mammals is restricted to two telencephalic constitutively active zones but appears more widespread in other vertebrates like reptiles, birds, and fish. Without exception, neuronal production in these species occurs throughout life. In teleost, proliferation sites have been found inmany regions of the brain. They are generally restricted to discrete foci, suggesting that niches of stem cells might exist in fish. Adult neural stem cells are characterized by their slow rhythm of cell cycle, correlated with their self-renewal properties. In medaka fish, we have shown that the optic tectum, the dorsal part of the mesencephalon grows throughout life by proliferation of cells at its margin. To provide support to the hypothesis of a stem cell nature of these peripheral cells, we analyzedwhether they express characteristic neural stem cell (NSC) markers. We compared the expression patterns of markers of multipotent neural stem cell genes (Sox2/Musashi/Bmi1) during the development and in adult brain. All thesemarkers are expressed in the brain proliferative zone during the development. In the adult optic tectum these genes are express in the marginal most regions of the proliferativezone. Tocharacterizemitotic activities in this region,we performed analysis basedon the incorporationof nucleoside analogs during cell division in fry and adult fishes. The nucleoside analogs 5iodo-2-deoxyuridine (IdU) and 5-chloro-2-deoxyuridine (CldU), which can be specifically immuno-detected, are used in double labelling experiments. This strategy allows the subset of long-term label retaining cells that are stem cells to be positively identified. We found double labelled cells in themostmarginal zone of the optic tectum. Conclusion: We identified a new population of neural stem cell like progenitors in the medaka adult optic tectum. These cells are slow proliferating, express the neural stem cell markers bmi-1, sox2, musashi 1 and are long lasting progenitors.