Neff A W, Yokota H, Chung H M, Wakahara M, Malacinski G M
Medical Sciences Program, School of Medicine, Indiana University, Bloomington 47405.
Dev Biol. 1993 Jan;155(1):270-4. doi: 10.1006/dbio.1993.1024.
Anuran amphibian embryos (Xenopus laevis and Rana dybowskii) are sensitive to novel gravitational fields. Under simulated weightlessness, (i) the location of the first horizontal cleavage furrow was shifted toward the vegetal pole at the eight-cell stage; (ii) the position of the blastocoel was more centered, and the number of cell layers in the blastocoel roof was increased at the blastula stage; (iii) the dorsal lip appeared closer to the vegetal pole at the gastrula stage; and (iv) head and eye dimensions were enlarged at the hatching tadpole stage. Effects of simulated hypergravity were opposite to those of simulated weightlessness, except that hypergravity, unlike simulated weightlessness, reduced the number of primordial germ cells in feeding tadpoles. Despite those dramatic differences in the early embryogenesis, tadpoles at the feeding stage are largely indistinguishable from controls.
无尾两栖动物胚胎（非洲爪蟾和东北林蛙）对新的重力场敏感。在模拟失重条件下，（i）八细胞期时，第一条水平卵裂沟的位置向植物极偏移；（ii）囊胚期时，囊胚腔的位置更居中，且囊胚腔顶部的细胞层数增加；（iii）原肠胚期时，背唇似乎更靠近植物极；（iv）孵化蝌蚪期时，头部和眼睛尺寸增大。模拟超重的影响与模拟失重的影响相反，不同的是，与模拟失重不同，超重会减少摄食期蝌蚪的原始生殖细胞数量。尽管早期胚胎发育存在这些显著差异，但摄食期的蝌蚪与对照组在很大程度上难以区分。
