Hybrid-versus-parental strain reaction. II. Comparative mortality in parental strain mice of different H-2 genotypes.

Lethally irradiated perental strain mice were inoculated with marrow from reciprocal hybrid donors. Hybrid cells could recognize the quantitatively greater antigenicity of parental strain recipients. The severity of the hybrid-versus-parental strain and parental strain-versus-hybrid reactions was compared. There was a significantly less severe reaction when DBA/2 mice were inoculated with (DBA/2female X C57BLmale)F1 arrow than with (C57BL X DBA/2)F1 marrow, which indicated a maternal influence on antigen recognition. The reaction of (DBA/2 X C57BL)F1 against DBA/2 recipients was significantly less severe than the DBA/2 reaction against (DBA/2 X C57BL)F1 recipients. All reactions involving C57BL were equally severe and more lethal than those involving DBA/2 mice. The strength of these reactions was a function of the relative tissue antigenicity and responsiveness of the parental strains of the hybrid cross. Both the expression of tissue antigens and the ability to recognize and respons to them are influenced by the maternal strain of the hybrid cross.