Evolutionary conservation analysis between the essential and nonessential genes in bacterial genomes.
Essential genes are thought to be critical for the survival of the organisms under certain circumstances, and the natural selection acting on essential genes is expected to be stricter than on nonessential ones. Up to now, essential genes have been identified in approximately thirty bacterial organisms by experimental methods. In this paper, we performed a comprehensive comparison between the essential and nonessential genes in the genomes of 23 bacterial species based on the Ka/Ks ratio, and found that essential genes are more evolutionarily conserved than nonessential genes in most of the bacteria examined. Furthermore, we also analyzed the conservation by functional clusters with the clusters of orthologous groups (COGs), and found that the essential genes in the functional categories of G (Carbohydrate transport and metabolism), H (Coenzyme transport and metabolism), I (Transcription), J (Translation, ribosomal structure and biogenesis), K (Lipid transport and metabolism) and L (Replication, recombination and repair) tend to be more evolutionarily conserved than the corresponding nonessential genes in bacteria. The results suggest that the essential genes in these subcategories are subject to stronger selective pressure than the nonessential genes, and therefore, provide more insights of the evolutionary conservation for the essential and nonessential genes in complex biological processes.
Department of Physics, Tianjin University, Tianjin 300072, China.
Hao
H
Luo
1] Department of Physics, Tianjin University, Tianjin 300072, China [2] Key Laboratory of Systems Bioengineering, (Ministry of Education), Tianjin University, Tianjin 300072, China [3] SynBio Research Platform, CollaborativeInnovation Center of Chemical Science and Engineering, Tianjin 300072, China.
Feng
F
Gao
Department of Physics, Tianjin University, Tianjin 300072, China.
Yan
Y
Lin
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods*; D017124:Conserved Sequence / Q000235:genetics*; D019143:Evolution, Molecular; D005798:Genes, Bacterial / Q000235:genetics*; D020043:Genes, Essential / Q000235:genetics*; D016680:Genome, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data
D001426:Bacterial Proteins