Isolation of a cDNA copy of an RNA species expressed in murine pre-B cells

Abstract

A part of a gene, pZ 183, was isolated from a cDNA library constructed from poly(A)-containing RNA of the chemically induced murine pre-B lymphoma 70Z/3. This DNA sequence was found to be present in one of 5,000 cDNA clones in the unsubtracted library, and in one of 350 cDNA clones in a library in which sequences common to 70Z/3 and to a T cell hybridoma had been subtracted. This indicates that the corresponding gene belongs to the genes which are expressed with low to medium abundance in the pre-B cell line 70Z/3. The gene was found to be expressed in pre-B lymphomas, but not in B lymphomas, myelomas, T cell lymphomas, macrophage tumors or a fibroblast line. By in situ hybridization it was detected in 2-4% of fetal liver cells between day 15 and 16 of gestation, and in 1% of adult bone marrow cells. It was not detected in thymus cells, nor in mature T cells, spleen, adult liver, kidney, heart, lung or brain. The size of the transcript found in all pre-B cell lymphomas is 1.2 kb in length. The pZ 183 DNA sequence would appear to be a useful B-lineage specific marker which identifies pre-B cells at various stages before the mature B cell.