A PCR method to detect the mouse major histocompatibility complex H2-Ld gene that confers resistance to Toxoplasma encephalitis.

In laboratory mice, the H2-Ld gene confers resistance to encephalitis upon infection with Toxoplasma gondii, a foodborne parasite capable of infecting all endotherm animals tested. H2-Ld is carried by inbred strains with major histocompatibility complex (MHC) haplotypes H-2a (e.g., A/J) and H-2d (e.g., BALB/c), but not by those with haplotypes H-2b (e.g., C57BL/6) and H-2k (e.g., C3H/He). As H2-Ld is typically detected by serological typing of ex vivo spleen samples, testing is usually terminal. Here we present a polymerase chain reaction (PCR)-based method to reliably detect the H2-Ld gene in ear biopsies from live mice, thus allowing researchers to ascertain the H2-Ld genotype for breeding or other in vivo procedures.