194 ALPHABETICAL COMPILATION 



NUCLEOPROTEINS 



See also Proteins and Phosphorus Metabolism 



Historical.- — Mathews (1897) discovered a substance in Arbacia lixula sperm, not a 

 protamine, but similar to a histone, in combination with nucleic acid, which he 

 called "arbacin". Mathews (19 15, p. 174) extracted a very small amount of nucleic 

 acid ( ?) from unfertilized Arbacia punctulata eggs. 



Amount in Eggs and Embryos. — Blanchard (1935) obtained 12.75 g"i- of crude 

 nucleic acid from 4,820 gm. of unfertilized eggs ; i .08 gr. of desoxyribose nucleic 

 acid (DNA) and about same amount of ribose nucleic acid, its pentose derivative 

 (RNA). 



For more recent figures on amounts of DNA and RNA in eggs and embryos see 

 Table 17 under Phosphorus Metabolism. 



Amount of RNA phosphorus in unfertilized egg is 20 X io~* micrograms; DNA 

 phosphorus 0.7 to i x io~^ micrograms. DNA/RNA = 0.05 in unfertilized egg, 

 0.17 in 8-hour embryo (blastula), 0.46 in 24-hour embryo (pluteus). RNA in un- 

 fertilized egg does not change in early development, but DNA increases during 

 cleavage until pluteus stage ; hence DNA of fertilized egg probably does not come 

 from RNA of unfertilized egg as earlier postulated by Brachet in other species 

 (Schmidt, Hecht, and Thannhauser, 1948; see also Villee, Lowens, Gordon, Leonard 

 and Rich, 1949; Villee, Villee and LaPlace, 1953). DNA of blastula is 10 x RNA 

 (Abrams, 1951; see Schmidt et al., 1948). Marshak and Marshak (1953) give 

 amounts in an unfertilized egg as RNA 2.4 X io~^ micrograms, DNA 8.1 x io~* 

 micrograms, and state that there is no detectible Feulgen-positive material in the 

 nucleus of the mature ovum. 



Location in Egg. — In other species ( Paracentrotus lividus, Psammechinus miliaris, etc.) 

 it has been shown that DNA is located in the nucleus, but there is also some RNA; 

 RNA is mostly in cytoplasm near nuclear membrane and in germinal vesicle of 

 immature egg (work of Brachet and Casperson) . See Runnstrom in Modern Trends 

 (1952, p. 65); Brachet's Chemical Embryology (1950, p. 212); Brachet (1947, 1952); 

 Casperson and Schultz (1940). 



In A. punctulata. — Location of RNA-proteins in eggs (Tsuboi, 1953). Location of 

 nucleic acid compounds in immature, mature and centrifuged eggs and half-eggs 

 as photographed by ultraviolet light (E. B. Harvey and Lavin, 1944, 195 1 a). Feulgen 

 reaction negative in parthenogenetic merogones, positive in fertilized merogones 

 (E. B. Harvey, 1940 c, p. 186). RNA present in cell cortex, vitelline and fertilization 

 membranes (Lansing and Rosenthal, 1949, 1952). 



Feulgen Reaction. — For determination of DNA. See Gray's Experimental Cytology 

 (1931, p. 84); Brachet (1933, 1937, 1950); Pasteels and Lison (1950, p. 448); 

 McClung's Microscopical Technique (1950, p. 135); Gomori (1952). For recent apprai- 

 sals of the Feulgen reaction see Brachet (1952, p. 176) ; Lesler (1953) ; Lumb (1950). 

 Amount and Location in Sperm. — Nucleic acid 29.66 % (in A. lixula, Mathews, 1897). 

 RNA I % of amount in egg; DNA 3 % of amount in egg (Schmidt, et al., 1948). 

 Sperm contributes i/30th as much DNA to fertilized egg as does the egg (Mazia, 

 1949b). DNA, about o.g x 10^® micrograms in one Arbacia sperm (Mazia, personal 

 communication, July 1951). Marshak and Marshak (1953) give 7.9 x io~' micro- 

 grams DNA in one sperm. RNA activity localized in middle piece of sperm (Di 

 Stefano and Mazia, 1952). Two DNA fractions in sperm (Barton, 1951, 1952). 



Analysis and Synthesis. — Methods of extraction and analysis (Schmidt and Thann- 

 hauser, 1945; Schmidt, ^M/., 1948; Villee, ef a/., 1949; Mazia, 1949b; Abrams, 1951, 

 with isotope tracers; Marshak and Vogel, 1951). Analysis of phosphorus fractions 

 (Crane, 1947; Schmidt, et al., 1948; Villee, et al., 1949, 1950, see Table 17 under 

 Phosphorus Metabolism) . Purines, adenine and guanine extracted from unfertilized 

 eggs (Blanchard, 1935). Purines and pyrimidines, adenine, cytosine, thymine ex- 



