Kiichi Iwamoto

Biochemical Studies during the Development of the Chick Embryo: Part IV Determination of Deoxyribosides in the Acid Soluble Fraction of the Chick Embryo and those Changes with the Incubation

The presence and the change of deoxyribosidic compounds in the acid extract of the embryo with the incubation were examined with an aid of the organism, L. leichmannii. The main deoxyribosidic compounds in the extract prepared from the 18 th day embryo were identified as uracil, cytosine and thymine deoxyribosides and deoxyribotides of cytosine and thymine from the behaviour on paper chromatographic and paper electrophoretic separation. A small amount of purine deoxyribosyl compound which was assumed as hypoxanthine deoxyriboside was detected, and the content of which per 1 g of fresh embryo changed with the lapse of the incubated day; especially, the content was minimum at the period from the 10 th to 15 th day incubation. At this period, the total growth promoting compounds contained 50% of deoxyribotide though deoxyribosides was lower than that of the other days. This period is the most significant stage of the embryo growth and the most active time of synthesis of DNA through the embryo growth.

Biochemical Studies During the Development of the Chick Embryo: Part I. Dynamic Changes of Nucleic Acids and Vitamin B12

The days when the concentration of conjugated- and free- vitamin B12 per wet weight g increased or decreased agreeded with that of nucleic acids in the chick embryo from 3rd through 18th day of incubation. It is intereresting that the day of increasing or decreasing of those compounds concentration corresponds with the important stages through the growth of embryo. The changes of these compounds in the egg contents free of embryo were estimated. Although a considerable large amount of free vitamin B12 was contained in the embryo, the most vitamin B12 in the egg content except the embryo existed in the conjugated state. It seems that the amount of total vitamin B12 in the egg during the incubation is relatively constant.