From Lab to Nature: Thermal Adaptation in Bacterial Viruses

Background: The intermediate filament Nestin has been reported as a marker for stem cells and specific precursor cell populations in the developing mammalian central nervous system (CNS). Nestin expressing precursors may give rise to neurons and glia. Mouse nestin expression starts at the onset of neurulation in the neuroectodermal cells and is dramatically down regulated when progenitor cells differentiate and become postmitotic. It has been reported that in the adult zebrafish (Danio rerio) active neurogenesis continues in all major subdivisions of the CNS, however few markers for zebrafish precursors cells are known, and Nestin has not been described in zebrafish. Results: We cloned a zebrafish nestin gDNA fragment in order to find a marker for precursor cells in the developing and postembryonic brain. Phylogenetic tree analysis reveals that this zebrafish ortholog clusters with Nestin sequences from other vertebrates but not with other intermediate filament proteins. We analyzed nestin expression from gastrula stage to 4 day larvae, and in postembryonic brains. We found broad expression in the neuroectoderm during somitogenesis. In the larvae, nestin expression progressively becomes restricted to all previously described proliferative zones of the developing and postembryonic central nervous system. nestin expressing cells of the forebrain also express PCNA during late embryogenesis, identifying them as proliferating precursor or neural stem cells. nestin is also expressed in the cranial ganglia, in mesodermal precursors of muscle cells, and in cranial mesenchymal tissue. Conclusion: Our data demonstrate that in zebrafish, like in mammals, the expression of the intermediated neurofilament nestin gene may serve as a marker for stem cells and proliferating precursors in the developing embryonic nervous system as well as in the postembryonic brain. Background The intermediate filament Nestin has been reported as a marker for stem cells as well as precursor populations of specific cell types in the developing mammalian central nervous system (CNS) giving rise to both neurons and glia [1,2]. Nestin is classified as type IV neurofilament, which together with microfilaments and microtubules constitute a major component in the cytoskeleton. In contrast to other more general cytoskeletal elements, intermediate filaments are expressed in a cell type specific manner, and Published: 25 July 2007 BMC Developmental Biology 2007, 7:89 doi:10.1186/1471-213X-7-89 Received: 20 March 2007 Accepted: 25 July 2007 This article is available from: http://www.biomedcentral.com/1471-213X/7/89 © 2007 Mahler and Driever; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.