Allotypes inheritance

Figure 2.2 Genetic loci involved in the synthesis of rabbit immunoglobulins as determined by allotype inheritance. It is not known if Vh genes of group a, x and y exist in single or multiple copies. Observations of Vl region subgroups suggest existence of multiple Vl genes.

Knight, K.L. Becker, R.S. (1990). Molecular basis of the allelic inheritance of rabbit immunoglobulin VH allotypes implications for the generation of antibody diversity. Cell 60,963-970. 

Allotypic markers for human yl. y2, y3, a2 and e heavy chains have been defined as Glm, G2m, G3m, A2m and Em (WHO meeting, 1976 [172]). The subclass heavy chain allotypes Glm, G2m, G3m and A2m are normally inherited in specific combinations. Lefranc et al. (1979) [173] determined five major and four minor Gm-Am haplotypes in Tunisians and found different common haplotypes in Caucasoids and Negroids. Protein sequence comparisons demonstrate that there are only two amino acid differences between the G3m (b) and G3m (a) allotypes [155], Restriction length polymorphism has been found for the Ca2 gene [174] thus, independent identification of the A2m allelomorphs, which were previously distinguishable only by serology, has been established. 

This convenient chemical manipulation permitted the demonstration that the allotypic markers in the Vh and Ch regions of an individual IgG molecule are largely determined by the genes on a single chromosome (93). Thus, if a rabbit inherits parental chromosomes carrying the genes, a cP and respectively, its individual IgG molecules have the... 

Allotypes Allotypes are defined as intraspecies inherited antigenic determinants. They are present in some, but not all members of a species and in molecules of the same isotype. They result from the existence of multiple forms (alleles) of immunoglobulin genes at individual gene loci. 

Allotypes or genetic markers are antigenic determinants on Ig molecules which are inherited in Mendelian fashion and are detected by immunological methods. They have been identified in most mammalian species. 

Three sets of allotypic markers are recognized in human Ig, the closely linked Gm and Am factors and the independently inherited Inv system. In Table 1.4 are listed the current known factors. The alphabetical and numerical nomenclatures have been used in different laboratories in spite of the fact that the numerical nomenclature was reconunended by WHO in 1965. It was suggested in the last WHO meeting (Rouen, 1974) to keep both for the time being and when possible to identify the chain on which a given allotype is found. The signatories agreed to employ numbers for the allotypes on the k chains and al chains and to use Km instead of Inv. 

By studying combinations of V and C allotypes present on the molecules from animals doubly heterozygous for these markers, it was observed that a high percentage of the H chains retained the combination of markers inherited from the parents . That is, the majority of syntheses were directed by genes in... 

Genetic experiments on the idiotypes of the mouse have extended the original observation of idiotypic inheritance. Linkage of idiotypes to Ch allotypes has... 

One such case involved investigation of the linkage between two different mouse idiotypes (A5A and ARS), both linked to the A/J Ch allotype . The observation of a crossover between the ASA idiotype and the BALB/c allotype in one male mouse provided the opportunity to test linkage between these two idiotypes. The crossover mouse was bred and the new haplotype (allogroup) was shown to be inherited without the ARS idiotype. On the basis of these data, the chromosomes of the BALB/c, A/J and recombinant might be represented ... 

The presence in heterozygous cells of only one of two types of parentally inherited Ig allotypes was also found in humans (Pernis et al., 1970) and mice (Weiler, 1965). At the same time, it is possible that each of the allelic genes of the a and b loci in rabbits (as well as in other cases) is represented by a number of closely linked genes which control the synthesis of the variable part of the H-chain. These sections of H-chains demonstrated both common and different antigenic determinants (Landucci-Tosi et al., 1975 Mage et al., 1977). Also in populations of lym-... 

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