Section 11 — Immunogenetics 



C3H)Fi ', C3H and (DBA/2 C3H)Fi x 

 C3H have been classified for serum type by 

 immunodiffusion and H-2 type by hemagglutina- 

 tion. No recombination has been observed 

 among 363 individuals typed, indicating at the 

 95 per cent confidence level a recombination 

 frequency not greater than 1 per cent. Absorp- 

 tion, inhibition and blocking tests reveal no 

 antigenic relationship between Ss protein and 

 H-2 antigens. 



1. Genetics 46, 898, 1961 ; Genetics 48 (in press), 

 1963. 



11.22. Gamma-globulin Isoantigens (Allotypes) in 

 the House Mouse. Leonard A. Herzenberg, 

 Robert I. Mishell and Leonore A. Her- 

 zenberg (Bethesda, U.S.A.). 



Although genetic differences in gamma- 

 globulins have been recognized for some time 

 in the human and the rabbit, it was not until 

 1961 that a genetically determined isoantigen 

 in this class of serum proteins was found in the 

 house moused 1 ) We have reported a second such 

 antigen, designated it Gg-2 and shown it to be 

 determined by a single segregating genetic 

 factor. (2 > We have also shown that this antigen 

 is on antibody molecules of diverse specificities. 



Data to be presented will show that Gg-2 

 and an antigen (very likely identical to the one 

 reported by Kelus and Moor-Jankowski) 

 which we label Gg-1 are controlled by a pair of 

 allelic genes, designated Gg 1 and Gg 2 . Appro- 

 priate crosses with linkage testing stocks have 

 been set up to establish the linkage relations of 

 the Gg locus to known markers in the mouse. 



Whether these antigens are found only on 

 separate molecules of gamma-globulin in hetero- 

 zygotes and the submolecular location of the 

 antigenic determinants are questions under 

 study. 



1. A. Kelus and J. K. Moor-Jankowski, 

 Nature 191, 1405, 1961. 



2. J.WuNDERLiCHandL.A. Herzenberg, Records 

 of the Gen. Soc. of America, 31, 126, 1962. 



11.23. A Genetic Approach to the Mechanism of 

 Partial Immunological Tolerance. A. Len- 

 gerova, V. Matousek, and M. Vojtiskova 

 (Prague, Czechoslovakia). 



The clonal selection hypothesis of immunity 



presumes the existence of multiple clones of 

 globulin-producing cells, each genetically pre- 

 determined to form one (or a small number of) 

 specific antibody. The cells of a particular clone 

 can also develop specific non-reactivity (immuno- 

 logical tolerance) if their contact with the res- 

 pective antigen (or antigenic determinant) takes 

 place within a critical period of their matura- 

 tion. Tolerance of an antigenic complex is not 

 an all-or-nothing phenomenon occurring in 

 various degrees between complete reactivity 

 and non-reactivity. The hypothesis was being 

 tested that complete tolerance is the issue of a 

 series of independent events; the likelihood of 

 their occurring simultaneously thus greatly 

 depends upon the total number of clones involv- 

 ed in the formation of antibodies against the 

 given complex. 



Assuming the existence of n antigenic differ- 

 ences between two inbred mouse strains (A and 

 CBA), then the F2 individuals represent a dis- 

 tribution of antigenic differences from to n 

 with respect to each parental strain. Under the 

 hypothesis of n independently segregating histo- 

 compatibility loci and further hypothesis con- 

 cerning the probability of induction of tolerance 

 of k antigens from the inducing complex (Fi 

 hybrid spleen cells), the distribution of survival 

 times of both parental skin grafts has been cal- 

 culated and compared with that obtained in the 

 experiment. The consequences and limitations 

 of the model are discussed. 



11.24. Transplantation of Mammary Glands from 

 Two Strains of Mice to Fi Hybrids of these 

 Strains. James S. Thompson and Flavia 

 Richardson (Edmonton, Canada, and Bar 

 Harbor, U.S.A.). 



A technique has been developed for the trans- 

 plantation of mammary glands from C3H/HeJ 

 and C57BL/6 female mice to dorsal and nipple 

 line sites in female Fi hybrids of these two strains. 

 The effect of site of transplant and hetero- 

 chronicity upon the grafts has been investigated. 

 The site of transplant apparently had little 

 effect, except that glands in the nipple line were 

 sometimes suckled, whereas those in the dorsal 

 area were not suckled even though they lactated. 

 The percentage of successful grafts varied with 

 the age of both host and donor. With young 

 mice, four to six weeks of age, as both donors 

 and hosts, 80 to 100 per cent of the grafts per- 

 sisted in most series. As age of either host or 

 donor increased, the percentage of grafts accepted 

 declined, but there was considerable variation in 

 this respect from series to series. 



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