Differential expression of DNAseI-sensitive sites in metaphase chromosomes of T and B lymphocytes

Thirty-one recurrent DNAseI-sensitive sites were expressed in G-banded metaphases of cultured T and B lymphocytes. Approximately one-half of these sites were found in both T and B cells and the other half were differentially expressed in the two cell types. The DNAseI-sensitive sites showed a strong correlation with the chromosomal gene location of T-cell receptors, interleukins produced by lymphocytes, and mapped surface antigens involved in the activation/proliferation of lymphocytes. The findings suggest that the chromatin of these very active genes remain accessible to DNAseI during cell division, and may help determine their precise chromosomal location.