Emanuelsson Hadar, Palén Kjell
Zoophysiological Institute, University of Lund, Helgonavägen 3, S-223 62, Lund, Sweden.
Wilehm Roux Arch Dev Biol. 1975 Mar;177(1):1-17. doi: 10.1007/BF00848623.
Chick blastoderms, suppliedin vitro andin ovo with L-tryptophan at the primitive streak stage, showed in their continued development typical retardation of brain formation and somitogenesis in the embryo, whereas heart formation remained unaffected. In contrast to an overall reduction in size observed at the higher L-tryptophan concentrations, a moderate enlargement of the area opaca, compared with the controls, was found at the lower concentrations. This enlargement was combined with an increased flattening of the ectodermal area opaca cells and a reduction of the number of microvilli covering these cells. As a simultaneous supply of glucose could reduce, to some extent, the morphogenetic disturbances, these might partly be ascribed to a blocking of gluconeogenesis from L-tryptophan, but the overall reduction in size mentioned, together with the observation of a reduced decomposition of intracellular yolk granules in the L-tryptophan-treated blastoderms, indicates that impairment of intracellular yolk granule decomposition was the principal disturbance. The possible role of serotonin-probably formed from the L-tryptophan supplied-is suggested as a regulating factor in this connexion.
在原条期对鸡胚胚盘进行体外和卵内L-色氨酸供应，结果显示，在胚胎持续发育过程中，脑形成和体节发生出现典型的发育迟缓，而心脏形成未受影响。与较高L-色氨酸浓度下观察到的整体尺寸减小相反，在较低浓度下，与对照组相比，发现暗区有适度扩大。这种扩大伴随着暗区外胚层细胞扁平化增加以及覆盖这些细胞的微绒毛数量减少。由于同时供应葡萄糖可在一定程度上减少形态发生紊乱，这些紊乱可能部分归因于L-色氨酸糖异生的阻断，但上述整体尺寸减小以及在L-色氨酸处理的胚盘中观察到细胞内卵黄颗粒分解减少，表明细胞内卵黄颗粒分解受损是主要紊乱。提示血清素（可能由所供应的L-色氨酸形成）在此关联中作为调节因子发挥作用。
