Löwkvist B, Emanuelsson H, Heby O
Cell Differ. 1983 Jan;12(1):19-26. doi: 10.1016/0045-6039(83)90113-6.
Inhibition of polyamine synthesis in early chick embryos by in ovo treatment with DL-alpha-difluoromethylornithine (DFMO), injected beneath the blastoderm after 5 h of incubation, permanently blocks post-gastrular development. After the first day of polyamine limitation, the embryos possess a thickened primitive streak. Further morphogenesis is blocked and the ectoderm and mesoderm are condensed around the streak. There is obvious suppression of nucleolar formation in 24 h DFMO-treated embryos. In the mesoderm obliquely in front of Hensen's node the frequency of nucleolus-possessing cells is only a few percent lower in DFMO-treated than in control embryos. However, in the same area the frequency of mesoderm cells possessing multiple nucleoli is about 50% lower in the polyamine-depleted embryos. At the ultrastructural level, mesoderm cells from 24 h DFMO-treated embryos show a reduction of the fibrillar component of the nucleolus with a resulting segregation of the nucleolar material. Our data indicate that stimulation of polyamine synthesis is an obligatory step in the differentiation of epiblast cells into mesoderm cells.
在孵化5小时后，将DL-α-二氟甲基鸟氨酸（DFMO）注入胚盘下方进行鸡胚体内处理，抑制早期鸡胚中的多胺合成，会永久性地阻断原肠胚形成后的发育。在多胺受限的第一天后，胚胎的原条增厚。进一步的形态发生被阻断，外胚层和中胚层在原条周围凝聚。在经DFMO处理24小时的胚胎中，核仁形成明显受到抑制。在亨森结斜前方的中胚层中，经DFMO处理的胚胎中具有核仁的细胞频率仅比对照胚胎低几个百分点。然而，在同一区域，多胺缺乏的胚胎中具有多个核仁的中胚层细胞频率约低50%。在超微结构水平上，经DFMO处理24小时的胚胎的中胚层细胞显示核仁的纤维成分减少，导致核仁物质分离。我们的数据表明，多胺合成的刺激是上胚层细胞分化为中胚层细胞的一个必要步骤。
