Ramírez O, Alemán V
J Exp Zool. 1986 Apr;238(1):63-70. doi: 10.1002/jez.1402380108.
Thigh myogenic cells from 11-12-day-old chick embryos were cultured continuously in the presence of medium containing no chick embryo extract (CEE). It is known that CEE contains a muscle-inducing protein of 35,000 daltons. In spite of the absence of embryo extract and provided that calcium, starting at a concentration as low as 3 X 10(-4) M, was present in the tested media, typically aligned myotubes with 20 or more nuclei per fiber or abnormal myosymplasts were produced at will. In the first case, the result was systematically obtained when the media were unchanged. Consequently, the cell microenvironment remained undisturbed and therefore was autoconditioned throughout the 7 days of culture. In the second case, the result depended on the feeding schedules. Conversely, no myotubes were formed in cultures in embryo extract-free medium without calcium, irrespective of the frequency of medium changes. Insulin, a serum factor believed to be involved in syncytium formation process in vitro, was present in all tested media. Undialyzed or dialyzed fetal calf serum (FCS), used for the preparation of the media, contained 11 mu units of insulin per milliliter. The insulin content in all tested media was diluted, however, to one tenth the physiological serum concentration. The hormone did not promote any kind of myoblast fusion in any experiment in which calcium was deleted as a component of the tested media, regardless of the feeding schedule followed.(ABSTRACT TRUNCATED AT 250 WORDS)
将11至12日龄鸡胚的大腿肌原细胞在不含鸡胚提取物（CEE）的培养基中持续培养。已知CEE含有一种35000道尔顿的肌肉诱导蛋白。尽管没有胚胎提取物，并且只要测试培养基中存在低至3×10⁻⁴ M浓度的钙，就能随意产生每根纤维有20个或更多细胞核的典型排列的肌管或异常的肌合胞体。在第一种情况下，当培养基不变时系统地得到了该结果。因此，细胞微环境在整个7天的培养过程中保持未受干扰，从而实现了自调节。在第二种情况下，结果取决于换液时间表。相反，在无钙的无胚胎提取物培养基中培养时，无论换液频率如何，都不会形成肌管。胰岛素是一种被认为参与体外多核体形成过程的血清因子，存在于所有测试培养基中。用于制备培养基的未透析或透析的胎牛血清（FCS）每毫升含有11微单位胰岛素。然而，所有测试培养基中的胰岛素含量都被稀释至生理血清浓度的十分之一。在任何将钙从测试培养基成分中去除的实验中，无论遵循何种换液时间表，该激素都不会促进任何类型的成肌细胞融合。（摘要截短于250字）
