A model capturing novel strand symmetries in bacterial DNA

► We propose a simple stochastic model to construct primitive DNA sequences. ► The model provide an explanation for Chargaff's second parity rule in primitive DNA sequences. ► The model is also used to predict a novel type of strand symmetry in primitive DNA sequences. ► We extend the results for bacterial DNA sequences and compare distributional properties intrinsic to the model to statistical estimates from 1049 bacterial genomes. ► We find out statistical evidences that the novel type of strand symmetry holds for bacterial DNA sequences.