Migration and proliferation of cultured neural crest cells in W mutant neural crest chimeras.
Migration and proliferation of cultured neural crest cells in W mutant neural crest chimeras.
复制标题
DOI：
--
复制
发表时间：
1991-05
期刊：
影响因子：
4.6
通讯作者：
D. Huszar;A. Sharpe;R. Jaenisch
中科院分区：
文献类型：
--
作者：
D. Huszar;A. Sharpe;R. Jaenisch
通过聚集植入前胚胎产生的嵌合小鼠在研究哺乳动物毛色模式的发育方面发挥了重要作用。然而，这种方法不允许对神经嵴细胞（黑素细胞的前体）进行直接的实验操作。我们设计了一种系统，可以在体外实验操作后在体内评估神经嵴细胞的发育潜力和迁移。将培养的 C57Bl/6 神经嵴细胞在子宫内显微注射到神经化的 Balb/c 或 W 胚胎中，并显示可有效促进宿主动物的色素沉着。然而，所得的神经嵴嵌合体显示出不同的皮毛色素沉着模式，具体取决于宿主胚胎的基因型。 Balb/c 神经嵴嵌合体表现出非常有限的供体细胞色素贡献，主要局限于头部，而 W 突变体嵌合体则表现出广泛的色素沉着，通常超过皮毛的 50%。与Balb/c嵌合体相反，在Balb/c嵌合体中，供体成黑细胞似乎主要沿特征性的背腹方向迁移，在W突变体中，注射的细胞似乎沿纵向和背腹方向迁移，就好像细胞在空旷的空间中扩散一样。这与 W 突变体中缺乏功能性内源性黑素细胞群体是一致的，而 Balb/c 小鼠则含有完整的黑素细胞。我们的结果表明 W 突变干扰内源性成黑细胞的迁移和/或增殖。为了获得有关供体细胞克隆大小和混合程度的信息，将两个基因标记的神经嵴细胞群混合并共同注射到 W 胚胎中。在一半的三色嵌合体中，没有观察到供体嵴细胞的共定位，而在另一半中，发生了供体来源的颜色的精细混合。这些结果与嵌合体中的色素区域可以源自少数供体克隆的广泛增殖的假设相一致，这些克隆能够在宿主胚胎中定植大片区域。我们还分析了体外神经嵴培养物中色素沉着的发育，发现从携带wt或弱W等位基因的胚胎中移植的神经管产生色素沉着的黑素细胞，而更严重的W基因型与体外色素形成缺陷相关。
Chimeric mice, generated by aggregating preimplantation embryos, have been instrumental in the study of the development of coat color patterns in mammals. This approach, however, does not allow for direct experimental manipulation of the neural crest cells, which are the precursors of melanoblasts. We have devised a system that allows assessment of the developmental potential and migration of neural crest cells in vivo following their experimental manipulation in vitro. Cultured C57Bl/6 neural crest cells were microinjected in utero into neurulating Balb/c or W embryos and shown to contribute efficiently to pigmentation in the host animal. The resulting neural crest chimeras showed, however, different coat pigmentation patterns depending on the genotype of the host embryo. Whereas Balb/c neural crest chimeras showed very limited donor cell pigment contribution, restricted largely to the head, W mutant chimeras displayed extensive pigmentation throughout, often exceeding 50% of the coat. In contrast to Balb/c chimeras, where the donor melanoblasts appeared to have migrated primarily in the characteristic dorsoventral direction, in W mutants the injected cells appeared to migrate in the longitudinal as well as the dorsoventral direction, as if the cells were spreading through an empty space. This is consistent with the absence of a functional endogenous melanoblast population in W mutants, in contrast to Balb/c mice, which contain a full complement of melanocytes. Our results suggest that the W mutation disturbs migration and/or proliferation of endogenous melanoblasts. In order to obtain information on clonal size and extent of intermingling of donor cells, two genetically marked neural crest cell populations were mixed and coinjected into W embryos. In half of the tricolored chimeras, no co-localization of donor crest cells was observed, while, in the other half, a fine intermingling of donor-derived colors had occurred. These results are consistent with the hypothesis that pigmented areas in the chimeras can be derived from extensive proliferation of a few donor clones, which were able to colonize large territories in the host embryo. We have also analyzed the development of pigmentation in neural crest cultures in vitro, and found that neural tubes explanted from embryos carrying wt or weak W alleles produced pigmented melanocytes while more severe W genotypes were associated with deficient pigment formation in vitro.