Abstract: Using in situ hybridization technique with Diglabeled probe, the expression of p53 gene in mice’s embryo development has been studied in this thesis, the results can be summarized as fellows: p53 gene does not take part in the formation of organ proimordia during the development of embryo of age 9 ds and 10 ds. It takes part in the further process of organ differentiation ( concerned organs include eyes, brain, heart, lung, backbone and cranium viscerale,except liver) . On the one hand, p53 gene takes part in the cell regulation during embryo development, and on the other hand, it also takes part in coming processes, which do not relate with cell cycle. There are different regulation mechanisms in the different organs.

Key words: insitu hybridization, p53, cell cycle regulation, gene expression