Effects of differentiation of embryonal carcinoma cells (P19) on mitochondrial DNA content in vitro.

The embryonal carcinoma cell line P19 is derived from mouse teratocarcinomas. These pluripotent cells can be induced to differentiate into a variety of cell types by exposure to various drugs. We used retinoic acid to induce embryonal carcinoma cells to differentiate into neuronlike cells. In this study, we show that changes occur in mitochondria during differentiation of embryonal carcinoma cells to neuronlike cells. We found that various morphologic parameters such as mitochondrial fractional area and mitochondrial size decrease as embryonal carcinoma cells differentiate into neuronlike cells. Similar changes were also observed in mitochondrial DNA content. Stereologic analysis of cell preparations provided a measure of mitochondrial fractional area per cell and mtDNA content was assessed by radiolabeled mtDNA probe. This study establishes that mitochondria are regulated as cells differentiate.