Expression of the mitochondrial genome in HeLa cells: V. Transcription of mitochondrial DNA in relationship to the cell cycle

Abstract

An investigation of the rate of incorporation of [5- 3H]ur dine into mitochondrial RNA in synchronized HeLa cells in different phases of the cell cycle has revealed a considerable acceleration of this incorporation in cells in S and especially in G 2 phase. An analysis of the labeling of the intramitochondrial UTP pool has shown that this acceleration reflects a true increase in the rate of synthesis of mitochondrial RNA: this increase is considerably greater than can be accounted for by the expected doubling of mit-DNA ‡ ‡ Abbreviation used: mit-DNA, mitochondrial DNA. templates during the S and G 2 phases.