embryo 復習
心筋梗塞のサルがiPS細胞によって回復したそうです。
Japanese researchers regenerate monkey hearts with lab-grown stem cells
In a step forward for organ regeneration, stem cells grown from a single monkey’s skin cells revitalised the damaged hearts of five sick macaques, Japanese scientists report.
The experiment builds towards the goal of providing a vast and uncontroversial source of rejuvenating cells to transplant into heart attack victims, the researchers wrote in the science journal Nature.
This would obviate the need to harvest stem cells from embryos or from transplant recipients themselves.
The team used so-called induced pluripotent stem cells (iPSCs).
These are created by stimulating mature, already specialised cells—such as a skin cell—back into a neutral, juvenile state from which they can develop into any other type of human cell.
Before the iPSC technique emerged, pluripotent stem cells were harvested from human embryos, which are destroyed in the process—a controversial practice.
There is a third category of stem cells, which can be directly harvested from humans.
（以下省略）
今回取り上げる単語は、embryo /ˈɛmbrɪəʊ/です。
Oxford Dictionary of English (Second Edition Reserved, Oxford University Press)によると、 “an unborn or unhatched offspring in the process of development”、 “[botany] the part of a seed which develops into a plant consisting of a plumule a radicle, and one or two cotyledons”などと定義されておりました。
『ジーニアス英和辞典』（第五版，大修館）で調べたところ、「胎芽，幼虫，胚」などと載っておりました。
胎芽は受精後８週間未満の生体のことを指し、それ以降のものを胎児(fetus)と呼ぶようです。
また比喩的に「始まり、初期」などとして使われるようで、 “in embryo”で「初期の段階で，未決定で」という意味になるようです。（Gomez）
