title: Mutational pressure dictates synonymous codon usage in freshwater unicellular α - cyanobacterial descendant Paulinella chromatophora and β - cyanobacterium Synechococcus elongatus PCC6301.
abstract: BACKGROUND
  Comparative study of synonymous codon usage variations and factors influencing its diversification in α - cyanobacterial descendant Paulinella chromatophora and β - cyanobacterium Synechococcus elongatus PCC6301 has not been reported so far. In the present study, we investigated various factors associated with synonymous codon usage in the genomes of P. chromatophora and S. elongatus PCC6301 and findings were discussed.
  
  
  RESULTS
  Mutational pressure was identified as the major force behind codon usage variation in both genomes. However, correspondence analysis revealed that intensity of mutational pressure was higher in S. elongatus than in P. chromatophora. Living habitats were also found to determine synonymous codon usage variations across the genomes of P. chromatophora and S. elongatus.
  
  
  CONCLUSIONS
  Whole genome sequencing of α-cyanobacteria in the cyanobium clade would certainly facilitate the understanding of synonymous codon usage patterns and factors contributing its diversification in presumed ancestors of photosynthetic endosymbionts of P. chromatophora.
authors.affiliation: Department of Biotechnology, Vignan University, Vadlamudi, 522 213 Guntur, Andhra Pradesh India.
authors.forename: Rahul Raveendran
authors.initials: RR
authors.lastname: Nair
authors.forename: Manivasagam Bharatha
authors.initials: MB
authors.lastname: Nandhini
authors.forename: Thilaga
authors.initials: T
authors.lastname: Sethuraman
authors.forename: Ganesh
authors.initials: G
authors.lastname: Doss
keywords: Chromatophore; Mutational pressure; Paulinella chromatophora; Synechococcus elongatus; Synonymous codon usage