Clayton R M, Thomson I, de Pomerai D I
Nature. 1979 Dec 6;282(5739):628-9. doi: 10.1038/282628a0.
Differentiating vertebrate embryo tissues pass through a stage when they have the potential for several pathways of differentiation, some of them revealed only by experimental manoeuvres. As differentiation proceeds, the potential for alternative pathways becomes progressively restricted and is eventually lost. We have investigated the molecular basis for this phenomenon, using the chick embryo retina, which has a potential for differentiation into lens cells. This potential requires special conditions for its manifestation; it declines during development and is finally lost before hatching. Lens protein (crystallin) mRNA is expressed in early embryo retina: its levels decline in parallel with the decline in lens-forming potential. There is also evidence of an ontogenic change in post-transcriptional regulation. Such a relationship between heterologous mRNA and heterologous differentiation potential may be of general application.
脊椎动物胚胎组织在分化过程中会经历一个阶段，此时它们具有多种分化途径的潜力，其中一些途径只有通过实验操作才能揭示。随着分化的进行，替代途径的潜力逐渐受到限制，最终丧失。我们利用鸡胚视网膜研究了这一现象的分子基础，鸡胚视网膜具有分化为晶状体细胞的潜力。这种潜力需要特殊条件才能显现；它在发育过程中下降，最终在孵化前丧失。晶状体蛋白（晶状体蛋白）mRNA在早期胚胎视网膜中表达：其水平与晶状体形成潜力的下降平行下降。也有证据表明转录后调控存在个体发育变化。这种异源mRNA与异源分化潜力之间的关系可能具有普遍适用性。
