Page 534 - Veterinary Immunology, 10th Edition

by heavy chain rearrangements.
VetBooks.ir development of pig B cells, whose numbers increase greatly during
The presence of the intestinal microbiota significantly assists the

the first 2 weeks of age, although receptor diversity may not

increase until 4 to 6 weeks of age. Germ-free pigs have serum
immunoglobulin levels 20- to 100-fold less than conventional pigs.
Conventional pigs exhibit much greater diversity in their mucosal
IgM and IgA V genes than germ-free pigs.

Dogs and Cats

Dogs have 43 functional and 37 pseudogenes in their IGHV region.
Cats have 42 and 22 respectively.

Humans and Mice

Humans and mice use recombination to generate most of their

antibody diversity (Table 17.2). Additional diversity is generated by
base deletion and insertion and by somatic mutation. In these
species, B cells with diverse antigen receptors are produced
throughout life.

TABLE 17.2

Immunoglobulin Diversity Among Mammals

C GENE PRODUCTS C GENES V And V FAMILIES
H
L
L
H
Species
IgM IgD IgG IgE IgA λ κ H λ κ
Horses 1 1 7 1 1 7 1 7 1 ?
Bovine 2 1 3 1 1 4 1 1 2 ?
Sheep 1 1 3 1 2 >1 1 1 6 3
Pigs 1 1 8-12 1 1 1? 1 1 ? ?
Dogs 1 1 4 2? 1
Rabbits 1 0 1 1 13 8 2 1 ? ?
Mice 1 1 4 1 1 3 1 14 3 4
Humans 1 1 4 1 2 7 1 7 7 7
From Butler JE: Immunoglobulin gene organization and the mechanism of repertoire
development, Scand J Immunol 45:455-462, 1997, and other sources.

Intestinal Bacteria and Expansion of the B

Cell Repertoire

As pointed out previously, some mammals, including the large

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