Phospholipids in plant and animal chromatin

Isolated hepatic nuclei and hepatic chromatin have been analysed for their DNA, RNA, protein and phospholipid content. The protein/DNA ratio is 3 for nuclei and 1·95 for chromation extracted from Triton X‐100 treated nuclei. The phospholipids, (2·36 ± 0·91 (S.D.) per cent of the total nuclear material), are lost during the chromatin preparation mainly during the Triton X‐100 washings of the nuclei. Nevertheless, 10 per cent of the total nuclear phospholipids and fatty acid composition. Thus, the chromatin‐associated phospholipid cannot be attributed simply to contaminating nuclear membrane. This is supported by the autoradiographic study of semi‐thin sections of interphase nuclei from root apices of Vicia faba in which [3H] ethanolamine is clearly localized in the chromatin and nucleolar regions of the nuclei.