High telomerase is a hallmark of undifferentiated spermatogonia and is required for maintenance of male germline stem cells.
High telomerase is a hallmark of undifferentiated spermatogonia and is required for maintenance of male germline stem cells.
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DOI：
10.1101/gad.271783.115
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发表时间：
2015-12-01
影响因子：
10.5
通讯作者：
Artandi SE
中科院分区：
文献类型：
--
作者：
Pech MF;Garbuzov A;Hasegawa K;Sukhwani M;Zhang RJ;Benayoun BA;Brockman SA;Lin S;Brunet A;Orwig KE;Artandi SE
在这里，Pech等人使用端粒酶逆转录酶（TERT）报告小鼠，并显示非常高的端粒酶表达是未分化精原细胞的标志。这些结果提供了深入了解端粒酶的生殖细胞内的后生动物和证明，端粒维持生殖干细胞是一个中心的决定因素生殖细胞的不朽。端粒酶失活导致蠕虫、鱼和小鼠雄性生殖系的丧失，表明在该细胞谱系中对端粒维持的保守依赖。在这里，使用端粒酶逆转录酶（Tert）报告小鼠，我们发现，非常高的端粒酶表达是未分化的精原细胞，生殖干细胞所在的有丝分裂人口的标志。我们利用这些高端粒酶水平的基础上，纯化未分化的精原细胞使用荧光激活细胞分选。未分化精原细胞和胚胎干细胞中的端粒酶水平相当，并且比体祖细胞中的端粒酶水平高得多。在生殖细胞系中，我们发现了一个意想不到的端粒酶活性梯度，这也使得分离更成熟的群体成为可能。通过RNA测序对TertHigh未分化精原细胞和TertLow分化精原细胞的转录组学比较揭示了每个隔室的细胞周期和关键分子特征的显著差异。移植研究表明，生殖系干细胞活性仅限于TertHigh cKit−群体。端粒酶基因敲除株中端粒缩短导致未分化精原细胞耗竭，当未分化精原细胞降至临界阈值以下时，所有生殖细胞最终丧失。这些数据表明，端粒酶高表达是生殖系干细胞的一个基本特征，从而解释了在后生动物中广泛依赖端粒酶的生殖系永生。
Here, Pech et al. use telomerase reverse transcriptase (TERT) reporter mice and show that very high telomerase expression is a hallmark of undifferentiated spermatogonia. These results provide insight into the dependence on telomerase within the germline in metazoans and demonstrate that telomere maintenance in germline stem cells is a central determinant of germline immortality. Telomerase inactivation causes loss of the male germline in worms, fish, and mice, indicating a conserved dependence on telomere maintenance in this cell lineage. Here, using telomerase reverse transcriptase (Tert) reporter mice, we found that very high telomerase expression is a hallmark of undifferentiated spermatogonia, the mitotic population where germline stem cells reside. We exploited these high telomerase levels as a basis for purifying undifferentiated spermatogonia using fluorescence-activated cell sorting. Telomerase levels in undifferentiated spermatogonia and embryonic stem cells are comparable and much greater than in somatic progenitor compartments. Within the germline, we uncovered an unanticipated gradient of telomerase activity that also enables isolation of more mature populations. Transcriptomic comparisons of TertHigh undifferentiated spermatogonia and TertLow differentiated spermatogonia by RNA sequencing reveals marked differences in cell cycle and key molecular features of each compartment. Transplantation studies show that germline stem cell activity is confined to the TertHigh cKit− population. Telomere shortening in telomerase knockout strains causes depletion of undifferentiated spermatogonia and eventual loss of all germ cells after undifferentiated spermatogonia drop below a critical threshold. These data reveal that high telomerase expression is a fundamental characteristic of germline stem cells, thus explaining the broad dependence on telomerase for germline immortality in metazoans.