Mouse B-type lamins are required for proper organogenesis but not by embryonic stem cells.
B-type lamins, the major components of the nuclear lamina, are believed to be essential for cell proliferation and survival. We found that mouse embryonic stem cells (ESCs) do not need any lamins for self-renewal and pluripotency. Although genome-wide lamin-B binding profiles correlate with reduced gene expression, such binding is not directly required for gene silencing in ESCs or trophectoderm cells. However, B-type lamins are required for proper organogenesis. Defects in spindle orientation in neural progenitor cells and migration of neurons probably cause brain disorganizations found in lamin-B null mice. Thus, our studies not only disprove several prevailing views of lamin-Bs but also establish a foundation for redefining the function of the nuclear lamina in the context of tissue building and homeostasis.
Pubmed ID: 22116031 RIS Download
Animals | Body Size | Brain | Cell Cycle | Cell Differentiation | Cell Movement | Cells, Cultured | Chromatin | Embryonic Development | Embryonic Stem Cells | Female | Gene Expression Regulation, Developmental | Gene Silencing | Lamin Type B | Male | Mice | Mice, Knockout | Neural Stem Cells | Neurons | Nuclear Lamina | Organ Size | Organogenesis | Pluripotent Stem Cells | Promoter Regions, Genetic | Spindle Apparatus | Transcription, Genetic | Trophoblasts