The Nucleic Acid of the Eggs of Arbacia Punctulata

Quantitative determinations of the phosphorus distribution in the eggs of a variety of species by Tschernorutzki (l), Massing (2), and Needham and Needham (3) have indicated the probable presence of nucleoproteins in unfertilized ova. Unfortunately, however, the presence of vitellins in such cells renders the exact interpretation of such analyses somewhat difficult since, with current methods of analysis, it is possible that phosphoproteins of this type may be mistaken for nucleoproteins. In view of these facts it is of interest to determine the presence of nucleic acid in unfertilized ova by means of an actual isolation, which permits an examination of the characteristics of the substance isolated. For this purpose we have selected the eggs of the sea urchin, Arbaciu punctulata, whose alecithal nature facilitates the ease of the necessary chemical manipulations. In this connection it should be noted that Mathews (4) states: “The author got a substance with some of the properties of nucleic acid in some quantity from the unfertilized eggs of the sea urchin. It could not be positively identified, however, as the quantity was too small.”