[Effects on organ-development of mouse embryo by inhibiting NOR activity]

It is reported here that the NOR activity of mouse embryonic cells treated with BrdU in Vitro. The NOR activity could be recovered after incubating the cells in the BrdU-free medium. The inhibition of NOR activity in the early and mid-term gestation led to abnormal development as follows: the increase of fetus abortion in vivo and death rate of newborn offsprings, causing a congenital blindness in the newborn offsprings. The main reason for the blindness is a contamination of a plenty of the untransparent granules with a size of 0.3 micron in diameter from the epithelial cells. The relationship between the transcription of 18S and 28S rRNA genes and the embryonic organ development is also discussed in this paper.