Mansurov A N, Belousov L V
Ontogenez. 2011 Mar-Apr;42(2):126-32.
With the help of a suction manometric device, the relation between the deformation of Xenonus laevis embryo at the gastrula and neurula stages and the value of the applied force has been studied. Stiffness modules of embryonic tissues were in the order of several dozens of Pascal and they were inversely proportional during deformation from 40 to 20%. At the gastrula stage, a uniform or an increasing rate of expansion of the embryo body in the suction capillary with the diameter of approximately half that of the embryo was observed for 30 min after the action of the suction forces. The length of the stretched portion of the embryo correlates with the value of its deformation at the first minute. As a result of the expansion, the total body surface area of the deformed embryo increases more than twice compared to intact embryos. After expelling the embryo from the capillary, its surface reduced and the deformation became smoothened within 5 min, which indicates the existence of tensional force in the expanded embryo. These data confirm that, at the embryo gastrula stage, external mechanical forces do not only passively deform the embryo but also initiate the active expansion of the embryo which takes place at zero external force and overcomes the tensional resistance of tissues. The mechanism of active expansion and its link with the processes of normal morphogenesis are discussed.
借助吸力测压装置，研究了非洲爪蟾胚胎在原肠胚和神经胚阶段的变形与所施加力的值之间的关系。胚胎组织的刚度模量为几十帕斯卡量级，并且在从40%到20%的变形过程中它们成反比。在原肠胚阶段，在吸力作用后30分钟内，观察到胚胎在直径约为胚胎一半的吸力毛细管中身体均匀膨胀或膨胀速率增加。胚胎拉伸部分的长度与其在第一分钟时的变形值相关。膨胀的结果是，与完整胚胎相比，变形胚胎的总体表面积增加了两倍多。将胚胎从毛细管中排出后，其表面缩小，变形在5分钟内变得平滑，这表明膨胀的胚胎中存在张力。这些数据证实，在胚胎原肠胚阶段，外部机械力不仅使胚胎被动变形，还引发胚胎的主动膨胀，这种膨胀在零外力作用下发生，并克服组织的张力阻力。文中讨论了主动膨胀的机制及其与正常形态发生过程的联系。
