comparative genomics of mycoplasma analysis of conserved essential genes and diversity of the pan-genome支原体的比较基因组学分析pan-genome守恒的重要基因和多样性.pdf

Comparative Genomics of Mycoplasma: Analysis of Conserved Essential Genes and Diversity of the Pan- Genome 1 1 1 1 1 1 2 2 3 Wei Liu , Liurong Fang , Mao Li , Sha Li , Shaohua Guo , Rui Luo , Zhixin Feng , Bin Li , Zhemin Zhou , 2 1 1 Guoqing Shao , Huanchun Chen , Shaobo Xiao * 1 Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People’s Republic of China, 2 Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, People’s Republic of China, 3 Environmental Research Institute, University College Cork, Cork, Ireland Abstract Mycoplasma, the smallest self-replicating organism with a minimal metabolism and little genomic redundancy, is expected to be a close approximation to the minimal set of genes needed to sustain bacterial life. This study employs comparative evolutionary analysis of twenty Mycoplasma genomes to gain an improved understanding of essential genes. By analyzing the core genome of mycoplasmas, we finally revealed the conserved essential genes set for mycoplasma survival. Further analysis showed that the core genome set has many characteristics in common with experimentally identified essential genes. Several key genes, which are related to DNA replication and repair and can be disrupted in transposon mutagenesis studies, may be critical for bacteria survival especially over long period natural selection. Phylogenomic reconstructions based on 3,355 homologous groups allowed robust estimation of phylogenetic relatedness among mycoplasma strains. To obtain deeper insight into the relative ro