Inductive interactions and embryonic equivalence groups in a basal metazoan, the ctenophore Mnemiopsis leidyi
Inductive interactions and embryonic equivalence groups in a basal metazoan, the ctenophore Mnemiopsis leidyi
复制标题
基础后生动物栉水母 Mnemiopsis leidyi 中的诱导相互作用和胚胎等价群
DOI：
--
复制
发表时间：
2004
影响因子：
2.9
通讯作者：
M. Martindale
中科院分区：
文献类型：
--
作者：
J. Henry;M. Martindale
栉水母通过八排纵向排列的梳板纤毛的异时跳动进行运动。这些纤毛通常来自两个胚胎谱系，其中包括四个e1微粒的两个女儿（e11和e12）和四个m1微粒的一个女儿（m12微粒）。虽然e1谱系是自主建立的，但m1谱系需要来自e1谱系的诱导相互作用来促成梳板形成。在发育后期连续去除e1子代表明这种相互作用发生在32细胞期之后，并且可能在较长的发育期内进行。通常情况下，e11细胞最接近产生梳板纤毛的m12细胞;然而，e1子代（e11或e12）中的任何一个都能够发出m1后代形成梳板所需的信号。先前的细胞谱系分析表明，两个e1子代产生相同的细胞命运。另一方面，m1子体（m11和m12）通常会产生不同的细胞命运。相互m1子代缺失表明，在缺少一个子代的情况下，另一个细胞可以对缺失细胞正常形成的所有细胞类型进行基因评估。总而言之，这些发现表明，两个m1子体（m11和m12）代表了一个胚胎等价组或领域，两个m1子体的命运差异通常由细胞间相互作用控制。栉水母发育的这些综合特性，包括利用确定性卵裂分裂、诱导相互作用和建立胚胎场或等价群，与各种两侧后生动物发育中存在的特性非常相似。
Ctenophores undergo locomotion via the metachronal beating of eight longitudinally arrayed rows of comb plate cilia. These cilia are normally derived from two embryonic lineages, which include both daughters of the four e1 micromeres (e11 and e12) and a single daughter of the four m1 micromeres (the m12 micromeres). Although the e1 lineage is established autonomously, the m1 lineage requires an inductive interaction from the e1 lineage to contribute to comb plate formation. Successive removal of the e1 progeny at later stages of development indicates that this interaction takes place after the 32‐cell stage and likely proceeds over a prolonged period of development. Normally, the e11 cell lies in closest proximity to the m12 cell that generates comb plate cilia; however, either of the e1 daughters (e11 or e12) is capable of emitting the signal required for m1 descendants to form comb plates. Previous cell lineage analyses indicate that the two e1 daughters generate the same suite of cell fates. On the other hand, the m1 daughters (m11 and m12) normally give rise to different cell fates. Reciprocal m1 daughter deletions show that in the absence of one daughter, the other cell can gene‐rate all the cell types normally formed by the missing cell. To‐gether, these findings demonstrate that the two m1 daughters (m11 and m12) represent an embryonic equivalence group or field and that differences in the fates of the two m1 daughters are normally controlled by cell–cell interactions. These combined properties of ctenophore development, including the utilization of deterministic cleavage divisions, inductive interactions, and the establishment of embryonic fields or equivalence groups, are remarkably similar to those present in the development of various bilaterian metazoans.