The perpetual recycling of germ line stem cell pool
In mammals, the sperm production relies on the turnover of a minority germ line stem cell population. Although previous studies have shown that stem cells are sporadically lost and replaced in the course of turnover, leading to a consolidation of clonal diversity, their molecular identity and the cellular basis of replacement and loss remain unknown. Using a combination of in vivo live-imaging and static clonal fate assays in mouse, we have found that stem cells are defined by expression of GFRa1 and comprise both single cells and chains of syncytia, joined by interconnecting bridges. By correlating syncytial fragmentation with differentiation of neighbours, we have shown that this morphologically heterogeneous population of GFRa1 spermatogonia function as a single stem cell pool, establishing a new paradigm for tissue maintenance.
Hara K, Nakagawa T, Enomoto H, Suzuki M, Yamamoto M, Simons BD, Yoshida S. Mouse Spermatogenic Stem Cells Continually Interconvert between Equipotent Singly Isolated and Syncytial States. Cell Stem Cell. PMID: 24792118
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