Isolation and characterization of newly synthesized RNA and protein in mature bovine spermatozoa and effect of inhibitors on these syntheses

Freshly ejaculated mature bovine spermatozoa, freed of seminal plasma, were shown to synthesize RNAs which resemble bacterial rRNAs and tRNA, and a 16 S RNA which is not rRNA (16 S non rRNA). From the behaviour of the newly synthesized RNA in 4 commonly used fractionation systems, its hybridization with somatic cell, nuclear and miltochondrial DNAs, and the effect of drugs on its synthesis, it is concluded that the RNAs synthesized by spermatozoa are transcription products of their mitochondrial DNA. The 16 S non rRNA is found to be the most susceptible to degradation. The spermatozoa were shown to synthesize only a small number of proteins, probably only 5, all on a mitochondrial RNA template. The results show that in bovine spermatozoa, transcription and translation are largely, if not exclusively, confined to the mitochondrial DNA.