Kanatsu-Shinohara and colleagues continue to reveal the secrets of the rare mammalian spermatogonial stem cells. Their most recent study offers a new approach by applying principles from hematopoietic stem cell resear...Kanatsu-Shinohara and colleagues continue to reveal the secrets of the rare mammalian spermatogonial stem cells. Their most recent study offers a new approach by applying principles from hematopoietic stem cell research to demonstrate that cells which form a cobble- stone-like underlay beneath testicular somatic cells in culture are spermatogonial stem cells. Utilization of mouse models and cell cultures shows how the chemokine, CXCL12, fits into the signalling cascade which governs the fate of these cells and hence is essential to male fertility.展开更多
Aithough the key discovery of sex-deter- mining region Y （SRY） 20 years ago as the essential sex-determining gene emerged from studies of sex-reversed humans, most of our knowledge of how male and female germ cells ...Aithough the key discovery of sex-deter- mining region Y （SRY） 20 years ago as the essential sex-determining gene emerged from studies of sex-reversed humans, most of our knowledge of how male and female germ cells diverge after sex determination comes from studies of mice. This is demonstrated in a recent publication from Bowles and colleagues in Developmental Cell, which documents the functional importance of fibroblast growth factor 9 （FGFg） signalling in murine fetal germ cells.展开更多
Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to cont...Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to control access by transcription factors and other nuclear proteins to genomic DNA, to achieve appropriate modulation of cellular behaviors affecting cell fate. Importin-mediated nucleocytoplasmic transport relies on their specific recognition of cargoes, with each importin binding to distinct and overlapping protein subsets. Knowledge of importin function has expanded substantially in regard to three key developmental systems： embryonic stem cells, muscle cells and the germ line. In the decade since the potential for regulated nucleocytoplasmic transport to contribute to spermatogenesis was proposed, we and others have shown that the importins that ferry transcription factors into the nucleus perform additional roles, which control cell fate. This review presents key findings from studies of mammalian spermatogenesis that reveal potential new pathways by which male fertility and infertility arise. These studies of germline genesis illuminate new ways in which importin proteins govern cellular differentiation, includ ng v a d rect ng proteins to d st nct ntrace ular compartments and by determining cellular stress responses.展开更多
文摘Kanatsu-Shinohara and colleagues continue to reveal the secrets of the rare mammalian spermatogonial stem cells. Their most recent study offers a new approach by applying principles from hematopoietic stem cell research to demonstrate that cells which form a cobble- stone-like underlay beneath testicular somatic cells in culture are spermatogonial stem cells. Utilization of mouse models and cell cultures shows how the chemokine, CXCL12, fits into the signalling cascade which governs the fate of these cells and hence is essential to male fertility.
文摘Aithough the key discovery of sex-deter- mining region Y （SRY） 20 years ago as the essential sex-determining gene emerged from studies of sex-reversed humans, most of our knowledge of how male and female germ cells diverge after sex determination comes from studies of mice. This is demonstrated in a recent publication from Bowles and colleagues in Developmental Cell, which documents the functional importance of fibroblast growth factor 9 （FGFg） signalling in murine fetal germ cells.
文摘Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to control access by transcription factors and other nuclear proteins to genomic DNA, to achieve appropriate modulation of cellular behaviors affecting cell fate. Importin-mediated nucleocytoplasmic transport relies on their specific recognition of cargoes, with each importin binding to distinct and overlapping protein subsets. Knowledge of importin function has expanded substantially in regard to three key developmental systems： embryonic stem cells, muscle cells and the germ line. In the decade since the potential for regulated nucleocytoplasmic transport to contribute to spermatogenesis was proposed, we and others have shown that the importins that ferry transcription factors into the nucleus perform additional roles, which control cell fate. This review presents key findings from studies of mammalian spermatogenesis that reveal potential new pathways by which male fertility and infertility arise. These studies of germline genesis illuminate new ways in which importin proteins govern cellular differentiation, includ ng v a d rect ng proteins to d st nct ntrace ular compartments and by determining cellular stress responses.
