title: Parallel gene loss and acquisition among strains of different Brucella species and biovars.
abstract: The genus Brucella is divided into six species; of these, B. melitensis and B. abortus are pathogenic to humans, and B. ovis and B. neotomae are nonpathogenic to humans. The definition of gene loss and acquisition is essential for understanding Brucella's ecology, evolutionary history, and host relationships. A DNA microarray containing unique genes of B. melitensis Type strain 16MT and B. abortus 9-941 was constructed and used to determine the gene contents of the representative strains of Brucella. Phylogenetic relationships were inferred from sequences of housekeeping genes. Gene loss and acquisition of different Brucella species were inferred. A total of 214 genes were found to be differentially distributed, and 173 of them were clustered into 15 genomic islands (GIs). Evidence of horizontal gene transfer was observed for 10 GIs. Phylogenetic analysis indicated that the 19 strains formed five clades, and some of the GIs had been lost or acquired independently among the different lineages. The derivation of Brucella lineages is concomitant with the parallel loss or acquisition of GIs, indicating a complex interaction between various Brucella species and hosts.
authors.affiliation: Department of Infectious Disease Control, Beijing Institute of Disease Control and Prevention, Beijing 100071, P. R. China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Zhong
authors.forename: Yufei
authors.initials: Y
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Chen
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Ke
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.forename: Xitong
authors.initials: X
authors.lastname: Yuan
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Ruifu
authors.initials: R
authors.lastname: Yang
authors.forename: Guangneng
authors.initials: G
authors.lastname: Peng
authors.forename: Hai
authors.initials: H
authors.lastname: Jiang
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.forename: Hongbin
authors.initials: H
authors.lastname: Song
authors.forename: Buyun
authors.initials: B
authors.lastname: Cui
authors.forename: Liuyu
authors.initials: L
authors.lastname: Huang
authors.forename: Zeliang
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000818:Animals; D002002:Brucella / Q000235:genetics*; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D014644:Genetic Variation; D044404:Genomic Islands; D006801:Humans; D046228:Microarray Analysis; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D011995:Recombination, Genetic