Verna J M, Fichard A, Saxod R
Laboratoire de Biologie Animale, Université J. Fourier, Grenoble.
Biol Struct Morphog. 1989;2(2):60-6.
The differentiation of precocious embryonic epidermis in serum-free primary culture was analyzed by light and electron microscopic methods. Explants of 7-day chick embryo epidermis were grown on collagen or poly-L-lysine substrates in the absence of dermal mesenchyme. The serum substitute consisted of a mixture of insulin, transferrin, putrescine and seleneous acid together with (or without) Nerve Growth Factor. These culture conditions were shown to support proliferation, growth and development (evaluated using morphological criteria) of the epidermal explants up to 4-5 days; during this period, the epidermis underwent stratification; well-developed desmosomes as well as tonofilaments were formed and the epidermis achieved a morphology close to that of 10-11 day epidermis in ovo. However long-term survival of the explants was not obtained as cellular death, starting on day 5, progressively led to the necrosis of most parts of the explant. This morphological study demonstrates that the early phases of epidermal growth and maturation can occur to some extent in the virtual absence of dermal elements and serum factors. Chick embryo epidermal cells may thus possess the intrinsic ability to go through, at least for short periods in vitro, their differentiation programme. Then, at the onset of epidermal keratinization (12 days in ovo), they require specific exogenous factors to fully differentiate in vitro.
采用光镜和电镜方法分析了无血清原代培养中早熟胚胎表皮的分化情况。将7日龄鸡胚表皮外植体置于无真皮间充质的胶原蛋白或聚-L-赖氨酸底物上培养。血清替代物由胰岛素、转铁蛋白、腐胺和亚硒酸的混合物以及（或不包括）神经生长因子组成。这些培养条件被证明可支持表皮外植体增殖、生长和发育（根据形态学标准评估）长达4 - 5天；在此期间，表皮进行分层；形成了发育良好的桥粒以及张力丝，并且表皮达到了与卵内10 - 11日龄表皮相近的形态。然而，外植体未能长期存活，因为从第5天开始细胞死亡逐渐导致外植体大部分区域坏死。这项形态学研究表明，在几乎没有真皮成分和血清因子的情况下，表皮生长和成熟的早期阶段在一定程度上可以发生。因此，鸡胚表皮细胞可能具有内在能力，至少在体外短时间内经历其分化程序。然后，在表皮角质化开始时（卵内12天），它们需要特定的外源性因子才能在体外完全分化。
