Dondua A K
Ontogenez. 1994 Nov-Dec;25(6):68-76.
Data on early embryonic development of animals provided the basis for the following conclusions. In most (if not in all) species, germinal layers are not primitive structures recapitulating the initial organs of ancestral forms. The initial cell differentiation in the embryo is not directly associated with gastrulation, and the common concept of a fundamental relationship between germinal layer formation and cell differentiation is erroneous. Specification of cell types during early development and morphogenetic movements during gastrulation are relatively autonomous processes controlled by different genetic systems. The formation of germinal layers during individual development of different multicellular animals can be understood taking into account that segregation of cell layers is an essential element of epithelial morphogenesis. Movement of cells and cell layers during gastrulation is a specific manifestation of a general morphogenetic principle.
关于动物早期胚胎发育的数据为以下结论提供了依据。在大多数（即便不是所有）物种中，胚层并非重演祖先形式初始器官的原始结构。胚胎中的初始细胞分化与原肠胚形成并无直接关联，并且关于胚层形成与细胞分化之间存在根本关系的普遍观念是错误的。早期发育过程中细胞类型的特化以及原肠胚形成过程中的形态发生运动是由不同遗传系统控制的相对自主的过程。考虑到细胞层的分离是上皮形态发生的一个基本要素，就能够理解不同多细胞动物个体发育过程中胚层的形成。原肠胚形成过程中细胞和细胞层的运动是一个普遍形态发生原则的具体表现。
