THEORIES OF ANTIBODY PRODUCTION 



configuration that has been produced by living organisms. 

 It may be suggested as a corollary to this that if at a certain 

 stage of embryonic development certain synthetic elements 

 in mesenchymal cells were 'randomized', the possibility 

 might well emerge of producing all the 10,000 or more 

 patterns required. 



Table 2. A representation of the process of 

 immunological maturation 



Phase of differentiation or randomization 



Embryonic 



Birth or hatching 



Post-natal 



StabiHzation of patterns 



Development of tolerance by ehmination of 

 reacting clones 



-Critical point of Medawar 



Maturation 



Liberation of natural antibodies and poten- 

 tiality of antibody production 



Development 



Suppose that at the appropriate stage of development 

 a limited genetic determinant carrying the coding responsible 

 for globulin pattern releases control in such a fashion that 

 purely random arrangements are allowed which will be 

 different at each replication. Then at a later stage control 

 is re-established and the various random sequences are 

 stabilized as the guides to the genetic control of globulin 

 synthesis by the cell line concerned. This is still during 

 embryonic life when gamma globulins are not liberated into 

 the blood and are produced only to the extent necessary to 

 bring their specific patterns to the surface of the cell. It is at 

 this stage that contact with any determinant associated with 



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