The homologues of rabbit b-allotypes on hare immunoglobulin light chains: an evolutionary puzzle.

Most alloantisera directed against the rabbit allotypes b4, b5, and b6 cross-reacted with hare IgG. The determinants recognized by antisera against the three allotypes were shown to reside on the same hare L chains. Hare immunoglobulins, when injected into b4, b5, or b9 rabbits, elicited the formation of antibodies which reacted with hare IgG and cross-reacted with those rabbit allotypes (except b9) absent from the recipient. The anti-b9 antisera tested lacked reactivity with hare IgG.