Sada Aiko, Suzuki Atsushi, Suzuki Hitomi, Saga Yumiko
Department of Genetics, SOKENDAI, 1111 Yata, Mishima, Shizuoka 411-8540, Japan.
Science. 2009 Sep 11;325(5946):1394-8. doi: 10.1126/science.1172645.
Stem cells give rise to differentiated cell types but also preserve their undifferentiated state through cell self-renewal. With the use of transgenic mice, we found that the RNA-binding protein NANOS2 is essential for maintaining spermatogonial stem cells. Lineage-tracing analyses revealed that undifferentiated spermatogonia expressing Nanos2 self-renew and generate the entire spermatogenic cell lineage. Conditional disruption of postnatal Nanos2 depleted spermatogonial stem cell reserves, whereas mouse testes in which Nanos2 had been overexpressed accumulated spermatogonia with undifferentiated, stem cell-like properties. Thus, NANOS2 is a key stem cell regulator that is expressed in self-renewing spermatogonial stem cells and maintains the stem cell state during murine spermatogenesis.
干细胞可分化为不同的细胞类型，但也可通过细胞自我更新维持其未分化状态。利用转基因小鼠，我们发现RNA结合蛋白NANOS2对维持精原干细胞至关重要。谱系追踪分析显示，表达Nanos2的未分化精原细胞可自我更新并产生整个生精细胞谱系。出生后Nanos2的条件性破坏会耗尽精原干细胞储备，而Nanos2过表达的小鼠睾丸则积累了具有未分化、干细胞样特性的精原细胞。因此，NANOS2是一种关键的干细胞调节因子，它在自我更新的精原干细胞中表达，并在小鼠精子发生过程中维持干细胞状态。
