The histocompatibility-2 system in wild mice. XI. Ss and Slp properties of wild-derived H-2 haplotypes.

In this study, 14 B10.W lines were examined for genetic traits associated with the Ss protein and Slp alloantigen. Three B10.W lines were found to possess low levels of serum Slp alloantigen. Of these three Slp-positive lines, expression of the alloantigen was sex-limited in two lines (B10.LIB55 and B10.STA12) and constitutive, i.e., found in both sexes, in the remaining line (B10.KPB128). Lines which were found to be Slp-negative were also tested for IA-controlled immune response to Slp alloimmunization. The finding that one of these Slp-negative lines produced no detectable anti-Slp indicates that nonresponder alleles exist in wild populations. Further, the discovery of an unexpected immune response to Slp in F1 hybrids involving lines B10.LIB55 and B10.STA12 suggests the existence of a variant form of Slp alloantigen in these lines.