Differentiation of the O and p cell lines in the embryo of the leech. I. Sequential commitment of blast cell sublineages.
Differentiation of the O and p cell lines in the embryo of the leech. I. Sequential commitment of blast cell sublineages.
复制标题
水蛭胚胎中 O 和 p 细胞系的分化。
DOI：
10.1016/0012-1606(87)90430-1
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发表时间：
1987
影响因子：
2.7
通讯作者：
Shankland,M
中科院分区：
文献类型：
--
作者：
Shankland,M
胚细胞是发现于水蛭生发带外胚层的一组胚胎前体细胞。每个胚细胞通常经历相同的不变的细胞分裂序列，并在成熟水蛭中产生一组精确定义的独特可识别的神经元和表皮后代。本文用荧光谱系示踪剂对不同的p胚细胞子代进行了注射，以表征其后代克隆的细胞组成，结果表明，通过前三次p胚细胞分裂，后代细胞命运存在刻板的分离。先前的研究表明，当邻近的p细胞系发生消融时，通常由p母细胞产生的神经元和表皮特化将由不同的前体- o母细胞产生，如果o母细胞处于一定的分化阶段，当进行消融时，它将只产生正常p后代的一个子集。与目前研究结果的比较表明，在这些条件下，0胚细胞克隆不是简单地再现正常p胚细胞谱系的分支，而是表现出另一种谱系，其中p后代表现出异常的谱系关系。因此，尽管正常水蛭的发育包括一个几乎不变的细胞谱系，但谱系关系在实验条件下是开放的，可以进行相当大的重组。
The p blast cells are a group of embryonic precursors found in the ectodermal cell layer of the leech germinal band. Each p blast cell normally undergoes the same invariant sequence of cell divisions and gives rise to a precisely defined set of uniquely identifiable neuronal and epidermal descendants in the mature leech. In the present paper, various of the p blast cell progeny were injected with a fluorescent lineage tracer in order to characterize the cellular composition of their descendant clones, and the results show that there is a stereotyped segregation of descendant cell fates through the first three p blast cell divisions. Previous work has shown that neurons and epidermal specializations which normally descend from the p blast cell will arise from a different precursor—the o blast cell—in response to ablation of the neighboring P cell line and that if the o blast cell is at a certain stage of differentiation when the ablation is performed it will produce only a subset of the normal P descendants. Comparison with the present findings indicates that under those conditions the o blast cell clone is not simply recapitulating a branch of the normal p blast cell lineage, but rather manifests an alternative lineage in which P descendants exhibit an abnormal genealogical relationship. Thus, even though normal leech development comprises a nearly invariant cell lineage, lineage relationships are open to considerable reorganization under experimental conditions.