engleski

Analysis of developmental potential of postimplantation rat embryo in metabolically poor conditions by using combined in vitro and in vivo techniques

In vitro cultures are used in experimental embryology for investigation of developmental processes, regulatory factors and embryotoxic substances. However, differentation is restricted in in vitro conditions, even in the optimal cultivation medium with serum (1). Subsequent grafting under the kidney capsule shows that differentiation can be improved in richer environment (2). Since serum-free cultures are used for precise investigations, the question is how metabolically poor conditions affect developmental potential. In rat embryo cultivated 14 days in serum-free medium only epidermis and cartilage differentiates well, while other differentiated tissues are rare or absent. Epidermis retains its developmental potential during cultivation in serum-free medium (3). To analyse stability of in vitro restriction of developmental potential, rat embryos were cultivated in serum-free medium and then transplanted in vivo. Fisher rat embryos (E 9.5) were cultivated for 14 days in Eagle's minimal essential medium (MEM) alone and with 50% rat serum, as a control. The resulting teratomas were transplanted under the kidney capsule. After 14 days grafts were processed for histology, serially sectioned and analysed with light microscope. Regardless of presence of the serum epidermis with derivatives, respiratory and gut epithelium developed well in grafts. Cartilage and enchondral ossification were found. However, neural and adipose tissue, glandular epithelia, skeletal and smooth muscles differentiation was statistically lower in grafts precultivated in serum-free medium. It can be concluded that although the differentiation of that embryo cells in the serum-free conditions was restricted, cells retained to sigificant extent their developmental potential, which could be revealed after in vivo transplantation.

developmental potential; embryo culture; serum-free

nije evidentirano