Otto J J
J Exp Zool. 1977 Dec;202(3):307-22. doi: 10.1002/jez.1402020303.
The reorientation of the muscle processes of the ectodermal epithelial cells in Hydra attenuata has been examined during bud morphogenesis and in grafts inserted at right angles to their original orientation. The muscle processes were observed in histological preparations after staining with Mallory's Triple Stain and, in freshly fixed hydra, with polarization microscopy. Since the bud forms as an outpocketing from the parent, the ectodermal muscle processes, which run longitudinally, must reorient at some stage in order to be in the proper orientation on the bud. During the early stages of bud development, the reorientation of the ectodermal muscle processes is a passive result of the deformation of the parental tissue. Later, active reorientation occurs. The means by which muscle processes are able to reorient was studied further in rectangular grafts placed at right angles to their original orientation. In these grafts, muscle processes become aligned with those of the host in two ways: (1) in groups through the rotation of the whole graft or (2) individually, probably by retracting and then reextending in the new direction.
在细螅芽体形态发生过程中以及与原始方向成直角插入的移植物中，对细螅外胚层上皮细胞的肌突重新定向进行了研究。在用马洛里三色染色的组织学标本中以及在新鲜固定的细螅中，通过偏光显微镜观察肌突。由于芽体是从亲体向外突出形成的，纵向排列的外胚层肌突必须在某个阶段重新定向，以便在芽体上处于正确的方向。在芽体发育的早期阶段，外胚层肌突的重新定向是亲体组织变形的被动结果。后来，发生主动重新定向。在与原始方向成直角放置的矩形移植物中，进一步研究了肌突能够重新定向的方式。在这些移植物中，肌突通过两种方式与宿主的肌突对齐：（1）通过整个移植物的旋转成组对齐，或（2）单独对齐，可能是通过缩回然后在新方向上重新伸展。
