Biochemical Studies during the Development of the Chick Embryo

The devised method consists of the enzymatic hydrolysis, separation of deoxyribosides in the hydrolysate by paper chromatography and paper electrophoresis, and the estimation of the separated fractions with L. leichmannii. This method permits the determination of deoxyriboside composition of the smaller amounts of DNA or the related compounds with relatively higher accuracy even under the presence of some other compounds when nucleic acids and acid insoluble fractions of the chick embryo were analyzed.

The change of each deoxyriboside composition in acid insoluble fraction prepared from the 3 to 19 day old embryos investigated by the method. Among the major four deoxyribosides, the contents of deoxyguanosine and of deoxycytidine was nearly constant during the development of the embryo, whereas that of thymidine and of deoxyadenosine appeared to undergo the change slightly at the periods from 10 to 15 days incubation. It seems that this periods is also the most active time of the synthesis of DNA and of the changes of deoxyribosyl compounds in acid soluble fraction through the embryo growth.