Takano J, Sugiyama T
J Embryol Exp Morphol. 1984 Apr;80:155-73.
Chimaeric hydra strains were produced from a normal strain (105) and a naturally-occurring mutant strain (L4) which has a large polyp size, a low budding rate and a high head-inhibition potential. Various properties of the chimaeras were then examined and compared to those of the two parental strains. Hydra tissue consists of three cell lineages: the ectodermal epithelial, the endodermal epithelial and the interstitial cell lineages. Using the methods recently developed by Marcum & Campbell (1978b) and by Wanek & Campbell (1982), six chimaeric strains were produced which contained six different combinations of the three cell lineages from 105 and L4. Evidence obtained from the comparison of the chimaeras and their parental strains indicates that the ectodermal epithelial cell lineage in L4 is primarily responsible for the large polyp size and the low budding rate of this strain, whereas the endodermal epithelial cell lineage is largely, and the interstitial cell lineage is also partially, responsible for the high head-inhibition potential in L4. This suggests that the mechanisms determining the occurrence and location of bud formation and the mechanisms determining the inhibition potential levels are not related to each other (cf. Takano & Sugiyama, 1983; Bode & Bode, 1983). Evidence was also obtained which suggests that the levels of the head-activation and head-inhibition potentials in the chimaeras are determined independent of each other, apparently without the cross-catalytic relationship between them assumed in the Gierer-Meinhardt model (Gierer & Meinhardt, 1972; Meinhardt & Gierer, 1974).
嵌合水螅品系由一个正常品系（105）和一个自然发生的突变品系（L4）培育而成，L4品系具有息肉体型大、出芽率低和头部抑制潜力高的特点。然后对嵌合体的各种特性进行了检测，并与两个亲本品系的特性进行了比较。水螅组织由三个细胞谱系组成：外胚层上皮谱系、内胚层上皮谱系和间质细胞谱系。利用Marcum和Campbell（1978b）以及Wanek和Campbell（1982）最近开发的方法，培育出了六个嵌合品系，它们包含来自105品系和L4品系的三个细胞谱系的六种不同组合。对嵌合体及其亲本品系进行比较所获得的证据表明，L4品系中的外胚层上皮细胞谱系主要导致了该品系息肉体型大及出芽率低的特征，而内胚层上皮细胞谱系在很大程度上，间质细胞谱系也部分地导致了L4品系中较高的头部抑制潜力。这表明决定芽形成的发生和位置的机制与决定抑制潜力水平的机制相互之间没有关联（参见Takano和Sugiyama，1983；Bode和Bode，1983）。还获得了相关证据，表明嵌合体中头部激活和头部抑制潜力的水平是相互独立决定的，显然不存在Gierer-Meinhardt模型（Gierer和Meinhardt，1972；Meinhardt和Gierer，1974）所假设的它们之间的交叉催化关系。
