Synthesis of DNA in toluene-treated Chlamydomonas reinhardi (DNA replication-chloroplast DNA-cell cycle-electron microscopy).

Toluene-treated Chlamydomonas reinhardi incorporate deoxynucleoside triphosphates (dNTPs) into DNA. Incorporation requires all four dNTPs, but requires neither ATP nor added DNA. The incorporation reaction is linear for nearly 20 min. The product of synthesis in treated cells is mainly chloroplast (beta-component) DNA. However, a small quantity of nuclear (alpha-component) DNA is also synthesized. Synchronously grown cells are most efficient in dNTP incorporation at a time in the cell cycle when chloroplast DNA is normally replicated. Toluene treatment disrupts the internal morphology of the cell, but leaves the outer membrane of the chloroplast intact.