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Article citations


Suwanto, A. and Kaplan, S. (1989) Physical and Genetic Mapping of the Rhodobacter sphaeroides 2.4.1 Genome: Genome Size, Fragment Identification, and Gene Localization. Journal of Bacteriology, 171, 5840-5849.

has been cited by the following article:

  • TITLE: Multiple Chromosomes in Bacteria: Low Level of Evolutionary Constraint Drives the Rapid Genetic Divergence of Chromosome II

    AUTHORS: Cheramie Trahan, Ravi S. Pandey, Utkarsh Singh, Anushka Choudhary, Hyuk Cho, Rajeev K. Azad, Madhusudan Choudhary

    KEYWORDS: Multiple Chromosomes, Proteobacteria, Horizontal Gene Transfer, Selective Constraint, Pathogenic and Non-pathogenic Lifestyles

    JOURNAL NAME: Advances in Microbiology, Vol.9 No.7, July 31, 2019

    ABSTRACT: Multiple chromosomes in bacteria are designated as a larger primary chromosome (CI) and smaller accessory chromosomes (CII and CIII). Although previous studies examined multiple chromosomes in several bacterial species, the evolutionary mechanisms for the origin of CIIs still remain unclear. In this study, the four following hypotheses were tested. 1) CIIs exhibit lower sequence conservation and sequence divergence compared to their corresponding CIs across species of Proteobacteria. 2) The differential sequence divergence of CI and CII depends on pathogenic and non-pathogenic lifestyles. 3) CIIs harbor a higher level of horizontal gene transfers (HGTs) than CIs. 4) Orthologs located on CIIs experience less purifying selection than their corresponding orthologs on CIs. Results reveal a higher level of sequence conservation of CIs than the sequence conservation of CIIs. There is no significant difference in HGT estimates between CIs and CIIs. A majority of orthologous genes of CIs and CIIs experience purifying selection; however, genes on CIIs were significantly less constrained than the corresponding ones on CIs. This finding is true for both pathogenic and non-pathogenic bacteria, but the selective constraints for non-pathogenic bacteria are relatively less constrained. It was concluded that the differential selective constraint is a potent driving force for the rapid evolution of CII. Therefore, gene expression analysis at the transcriptome and proteome levels may shed light on the gene regulation mechanisms that might affect the sequence divergence between CI and CII.