Sequence analysis of nuclear matrix associated DNA from rat liver

The DNA associated with the nuclear matrix of rat liver was studied. The amount of DNA associated with the matrix varied with the concentration of DNase used in its preparation, but approached a plateau value of 1% of total nuclear DNA. We next studied the sequence complexity of this residual DNA. Using C₀t analyses, it was found that the complexity of matrix DNA was the same as that of total nuclear DNA, indicating that matrix DNA does not represent any specific sequence class. However, using ¹²⁵I-labeled ribosomal RNA (rRNA) as a probe, we found that the genes for rRNA are significantly enriched in the residual matrix DNA. The implications of these results are discussed.