Figure 3.

Pregnancy with male pups in B6 or B6-4KO females does not impair the ability to reject a male skin graft, and the ability to reject a male skin graft does not lead to a decrease in normal or IL4-deficient male offspring. (a) Schema of experiment: B6 and B6-4KO females were treated as in Fig. 2, except that instead of being boosted with male spleen cells at the time of mating, they received a male B6-4KO (test) and female (control) tail skin graft. All mice rejected their grafts and within 2 months the mice were re-mated and the resulting litters were examined. Y-axis, days from placement of graft until if completely fell off; the cross refers to the average time for complete rejection in B6 females. X-axis, % males per litter born. Open symbols represent mice which either were never mated or never got pregnant. Solid symbols represent animals which became pregnant. Circles, B6 females (n = 8); triangles, B6-4KO females (n = 4). Grey, first litters; black, second litters. Individual mothers are depicted by number. Thus, immunized mouse no. 2 was mated and grafted, had a litter with 42% males, and completely rejected a male skin graft within 35 days. Her second litter contained approximately 28% males. Mice numbers 3, 5 and 6 ate their first litters at birth.