Bromodeoxyuridine specifically labels the regenerative stem cells of planarians
Bromodeoxyuridine specifically labels the regenerative stem cells of planarians
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DOI：
10.1006/dbio.2000.9645
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发表时间：
2000-04-15
影响因子：
2.7
通讯作者：
Alvarado, AS
中科院分区：
文献类型：
--
作者：
Newmark, PA;Alvarado, AS
涡虫独特的再生能力需要一群被称为新母细胞的干细胞。响应于创伤，或在细胞更新的过程中，新成细胞被发出信号以分裂和/或分化，从而替换丢失的细胞类型。这些多能干细胞及其在真涡虫再生中的作用的研究已经严重阻碍了所报道的真涡虫无法将外源DNA前体，因此，很少有人知道的机制，控制增殖和分化的干细胞群体内的真涡虫。在这里，我们表明，真涡虫，事实上，能够将胸苷类似物溴脱氧尿苷（BrdU），允许neoblasts在细胞周期的S期被标记的具体。我们用BrdU标记法研究了完整动物体内成新细胞的分布，并直接显示了成新细胞的迁移和分化。我们已经研究的建议，一个子集的neoblasts被逮捕在G2期的细胞周期的BrdU和有丝分裂特异性标记物的双标记，我们发现，G2的中位数长度（类似6小时）是足够的帐户喂养或截肢后观察到的初始有丝分裂爆发。连续BrdU标记实验也表明，没有一个大的，缓慢循环的人口在完整的动物neoblast。特异性标记再生干细胞的能力，结合最近描述的使用双链RNA抑制基因表达的真涡虫，应重新点燃兴趣的扁虫作为一个实验模型，用于研究后生动物再生和控制干细胞增殖的问题。(C)北京大学出版社.
The singular regenerative abilities of planarians require a population of stem cells known as neoblasts. In response to wounding, or during the course of cell turnover, neoblasts are signaled to divide and/or differentiate, thereby replacing lost cell types. The study of these pluripotent stem cells and their role in planarian regeneration has been severely hampered by the reported inability of planarians to incorporate exogenous DNA precursors; thus, very little is known about the mechanisms that control proliferation and differentiation of this stem cell population within the planarian. Here we show that planarians are, in fact, capable of incorporating the thymidine analogue bromodeoxyuridine (BrdU), allowing neoblasts to be labeled specifically during the S phase of the cell cycle. We have used BrdU labeling to study the distribution of neoblasts in the intact animal, as well as to directly demonstrate the migration and differentiation of neoblasts. We have examined the proposal that a subset of neoblasts is arrested in the G2 phase of the cell cycle by double-labeling with BrdU and a mitosis-specific marker; we find that the median length of G2 (similar to 6 h) is sufficient to account for the initial mitotic burst observed after feeding or amputation. Continuous BrdU-labeling experiments also suggest that there is not a large, slow-cycling population of neoblasts in the intact animal. The ability to label specifically the regenerative stem cells, combined with the recently described use of double-stranded RNA to inhibit gene expression in the planarian, should serve to reignite interest in the flatworm as an experimental model for studying the problems of metazoan regeneration and the control of stem cell proliferation. (C) 2000 Academic Press.