Perah G, Feldman M
J Cell Physiol. 1977 May;91(2):193-9. doi: 10.1002/jcp.1040910205.
Experiments were performed to investigate the presence of colony-forming units (CFU) in the mouse embryonic yolk sac during the developmental period in which the yolk sac is the sole hemopoietic organ. Injection of yolk sac cell suspensions from normal embryos into syngeneic, lethally irradiated adult recipients evoked a very low number of spleen colonies. However, prior cultivation of yolk sacs in vitro caused a dramatic increase in the spleen colony-forming capacity--as high as 84-fold--following 48 hours in culture. The yolk sac origin of the spleen colonies was confirmed by: (a) Chromosomal marker analysis; (b) dose-response analysis; (c) demonstrating that the above colonies were not of endogenous origin induced by the mere injection of grafted cells. We conclude that the yolk sac contains many precursors of colony-forming cells which though undetectable by immediate grafting apparently become activated in culture by an as yet unknown induction process.
在胚胎发育期间，卵黄囊是唯一的造血器官，为此开展了实验以研究小鼠胚胎卵黄囊中集落形成单位（CFU）的存在情况。将正常胚胎的卵黄囊细胞悬液注射到同基因、经致死剂量照射的成年受体中，诱发的脾集落数量非常少。然而，卵黄囊在体外预先培养48小时后，其脾集落形成能力显著提高，高达84倍。通过以下方法证实了脾集落来源于卵黄囊：（a）染色体标记分析；（b）剂量反应分析；（c）证明上述集落并非仅由移植细胞注射诱导产生的内源性集落。我们得出结论，卵黄囊中含有许多集落形成细胞的前体细胞，尽管通过直接移植无法检测到这些细胞，但它们显然在培养过程中通过一个尚不清楚的诱导过程被激活。
