Incorporation of H-3-thymidine into mitochondrial DNA of quail oocytes and eggs.

The amount of mitochondrial DNA and its synthesis were investigated in quail oocytes during the last 20 days of their growth. As the oocyte grows the amount of DNA in it increases rapidly, but at the end of oogenesis the increase in the amount of DNA lags considerably behind the rate of increase in the volume of the oocyte. As the oocyte grows the incorporation of H-3-thymidine into mitochondrial DNA decreases. The synthesis of mitochondrial DNA in cells of the quail embryo in early stages of development takes place at the same rate as the synthesis of nuclear DNA and far more rapidly than is more inhibited by ethidium bromide and mitomycin than the synthesis of nuclear DNA.