Project description:Across life neural stem cells (NSCs) generate new neurons in the mammalian brain through asymmetric neurogenic and self-renewing cell divisions. However, the cellular mechanisms underlying NSC asymmetry remain unknown. Using fluorescence loss in photobleaching (FLIP) we here show that NSCs in vitro and within the developing forebrain generate a lateral diffusion barrier during cell division resulting in asymmetric segregation of cellular components. The strength of the diffusion barrier is dynamically regulated with age and depends on the proper function of lamin-associated nuclear envelope constituents. Strikingly, age-associated or experimental impairment of the diffusion barrier disrupts asymmetric segregation of damaged proteins, a product of aging. Thus, the data presented here identify a mechanism how age is asymmetrically distributed during somatic stem cell division. For microarray analysis we analysed gene expression in cells derived from the hippocampi of 6 week old (young) or 9 month old (old) male C57BL/6JRj mice. 6 samples were analyzed YoungNSC, 3 replicates OldNSC, 3 replicates
Project description:Across life neural stem cells (NSCs) generate new neurons in the mammalian brain through asymmetric neurogenic and self-renewing cell divisions. However, the cellular mechanisms underlying NSC asymmetry remain unknown. Using fluorescence loss in photobleaching (FLIP) we here show that NSCs in vitro and within the developing forebrain generate a lateral diffusion barrier during cell division resulting in asymmetric segregation of cellular components. The strength of the diffusion barrier is dynamically regulated with age and depends on the proper function of lamin-associated nuclear envelope constituents. Strikingly, age-associated or experimental impairment of the diffusion barrier disrupts asymmetric segregation of damaged proteins, a product of aging. Thus, the data presented here identify a mechanism how age is asymmetrically distributed during somatic stem cell division.
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in E9.0 mouse embryos.
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
