Tissue distribution of rat glutathione transferase subunit 7, a hepatoma marker.

Polyadenylated RNA isolated from NN-dimethyl-4-aminoazobenzene-induced rat hepatoma was used to prepare a cDNA library in lambda gt10. Full-length clones complementary to mRNA coding for glutathione transferase subunit 7 were isolated and one of these clones (pGSTr7) was fully characterized. In Northern blot analysis, mRNA hybridizing to 32P-labelled pGSTr7 was found in poly(A)-containing RNA isolated from seven normal rat tissues but not from testis and liver. A similar hybridizing mRNA species was also detected in human placental mRNA. The same probe, used in a Southern blot analysis of genomic DNA, suggests the presence of a multigene family in the rat.