Gvirtzman G, Goldstein R S, Kalcheim C
Department of Anatomy and Embryology, Hebrew University of Jerusalem-Hadassah Medical School, Israel.
J Neurobiol. 1992 Apr;23(3):205-16. doi: 10.1002/neu.480230302.
The microenvironment created by grafting rostral somitic halves in place of normal somites leads to the formation of nonsegmented peripheral ganglia (Kalcheim and Teillet, 1989; Goldstein and Kalcheim, 1991) and is mitogenic for neural crest (NC) cells that become dorsal root ganglia (DRG) (Goldstein et al., 1990). We have now extended these studies by using three surgical manipulations to determine how additional mesodermal tissues affected DRG growth in chick embryos. The following experimental manipulations were performed: (1) unilateral deletion of epithelial somites, similar deletions followed by replacing the somites with (2) a three-dimensional collagen matrix, or (3) fragments of quail lateral plate mesoderm. When somites were absent or replaced by collagen matrix, ganglia were unsegmented, and their volumes were decreased by 21% and 12%, respectively, compared to contralateral intact DRG. In contrast, when lateral plate mesoderm was transplanted in place of somitic mesoderm, NC cells migrated into the grafted mesoderm and formed unsegmented DRG whose volumes were increased by 62.6% compared to the contralateral ganglia. These results suggest that although DRG precursors do not require sclerotome to begin migration and condensation processes, DRG size is modulated by the properties of the mesoderm. Permissiveness to migration is positively correlated with an increase in DRG volume. This volume increase observed in grafts of lateral plate mesoderm is likely to result from enhanced proliferation of neural crest progenitors, previously demonstrated for DRG cells in rostral somitic grafts.
通过移植头侧体节半片代替正常体节所形成的微环境会导致非节段性外周神经节的形成（卡尔海姆和泰莱特，1989年；戈尔茨坦和卡尔海姆，1991年），并且对形成背根神经节（DRG）的神经嵴（NC）细胞具有促有丝分裂作用（戈尔茨坦等人，1990年）。我们现在通过三种手术操作扩展了这些研究，以确定额外的中胚层组织如何影响鸡胚中DRG的生长。进行了以下实验操作：（1）单侧切除上皮体节，类似的切除后用（2）三维胶原基质或（3）鹌鹑侧板中胚层碎片代替体节。当体节缺失或被胶原基质替代时，神经节是非节段性的，与对侧完整的DRG相比，它们的体积分别减少了21%和12%。相比之下，当侧板中胚层移植到体节中胚层的位置时，NC细胞迁移到移植的中胚层中并形成非节段性的DRG，其体积与对侧神经节相比增加了62.6%。这些结果表明，尽管DRG前体细胞开始迁移和凝聚过程不需要生骨节，但DRG的大小受中胚层特性的调节。迁移的允许性与DRG体积的增加呈正相关。在侧板中胚层移植中观察到的这种体积增加可能是由于神经嵴祖细胞增殖增强所致，这在头侧体节移植中的DRG细胞中已得到证实。
