440 



GERMINAL ORGANIZATION 



INDUCTION PHENOMENA 



TABLE 7 



DIFFERENCE IN INDUCTIVE POWER BETWEEN THE RIBONU CLE O P ROTE I NS 

 FROM LIVER AND FROM KIDNEY 



Compiled from Hayashi (1956) and Yamada and Takata (1956) 



Aspects considered 



Liver 



Whole JVon preci- Ribonucl eo- 



extract pitable protein 



fraction fraction 



Kidney 



Whole Non preci- Ribonucleo- 



extract pitable protein 



fraction fraction 



Electrophoresis 

 (pH 8.5 and 7.5) 



complex I component 



I component 



of the inductory power was observed. A similar experiment was tempted with cristalline 

 trypsin (0.01% at pH 7.6), with the important addition that this enzyme was inactivated 

 in the sample, before implantation, by heating at 85° C for 5 min. Strictly comparable 

 controls were used. Again with 30-, 60- and 120-min. trypsic digestion a progressive 

 suppression of induction was caused. With the longer exposure, only mesenchyme or 

 melanophores appeared. Thus, in this case, it is consistently established that the xeno- 

 inductor works through the proteic moiety of the ribonucleoprotein extracted from the 

 liver. 



Further tests have however revealed that, in spite of its apparent homogeneity, the 

 ribonucleoproteins extracted from guinea-pig liver are not always purely acrogenic and 

 may contain some deutogenic factors. In an attempt for further dissociation, Hayashi and 

 Takata (1958) have submitted the ribonucleoprotein extract, obtained as above, to high 



