Sandor S, Fazakas-Todea I
Morphol Embryol (Bucur). 1980 Jan-Mar;26(1):29-32.
In continuation of previous experiments, recent results concerning the determinism of somitogenesis are reported. By means of two experimental devices on explanted chick embryos the influence upon mesoderm segmentation of the early removal of ectoderm (neural plate)--before and during the formation of the first somite pairs--and removal of endo- and ectoderm after 36-40 hours of incubation was investigated. Up to date results attest that during the shaping of the first somites no essential epigenetic interrelations between overlying ectoderm (neural plate) and paraxial mesoderm are necessary for segmentation. Just before the onset of segmentation a labile determination seems to be present in the presumptive somitogenic mesoderm. As to the later role of endo- and ectoderm in segmentation, present results reveal a relative independence of the segmentation process. The absence of the above-mentioned layers does not prevent further segmentation but induces a progressive slowing down of the process.
在先前实验的延续中，报告了有关体节发生决定论的最新结果。通过在体外培养的鸡胚上的两个实验装置，研究了在第一对体节形成之前和期间早期去除外胚层（神经板）以及孵化36 - 40小时后去除内胚层和外胚层对中胚层分割的影响。最新结果证明，在第一体节形成过程中，覆盖的外胚层（神经板）和轴旁中胚层之间不存在对分割至关重要的表观遗传相互关系。就在分割开始之前，推测的体节发生中胚层似乎存在不稳定的决定作用。至于内胚层和外胚层在分割中的后期作用，目前的结果揭示了分割过程的相对独立性。上述层的缺失并不妨碍进一步分割，但会导致分割过程逐渐减慢。
