Abstract
Burkholderia mallei (Bm), the causative agent of the predominately equine disease glanders, is a genetically uniform species that is very closely related to the much more diverse species Burkholderia pseudomallei (Bp), an opportunistic human pathogen and the primary cause of melioidosis. To gain insight into the relative lack of genetic diversity within Bm, we performed whole-genome comparative analysis of seven Bm strains and contrasted these with eight Bp strains. The Bm core genome (shared by all seven strains) is smaller in size than that of Bp, but the inverse is true for the variable gene sets that are distributed across strains. Interestingly, the biological roles of the Bm variable gene sets are much more homogeneous than those of Bp. The Bm variable genes are found mostly in contiguous regions flanked by insertion sequence (IS) elements, which appear to mediate excision and subsequent elimination of groups of genes that are under reduced selection in the mammalian host. The analysis suggests that the Bm genome continues to evolve through random IS-mediated recombination events, and differences in gene content may contribute to differences in virulence observed among Bm strains. The results are consistent with the view that Bm recently evolved from a single strain of Bp upon introduction into an animal host followed by expansion of IS elements, prophage elimination, and genome rearrangements and reduction mediated by homologous recombination across IS elements.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 102-116 |
| Number of pages | 15 |
| Journal | Genome Biology and Evolution |
| Volume | 2 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2010 |
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Keywords
- Bacterial evolution
- Bacterial virulence
- Comparative genomics
- Genome erosion
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Genetics
Cite this
Continuing evolution of Burkholderia mallei through genome reduction and large-scale rearrangements. / Losada, Liliana; Ronningf, Catherine M.; Deshazer, David; Woods, Donald; Fedorova, Natalie; Kim, H. Stanley; Shabalina, Svetlana A.; Pearson, Talima R; Brinkac, Lauren; Tan, Patrick; Nandi, Tannistha; Crabtree, Jonathan; Badger, Jonathan; Beckstrom-Sternberg, Stephen M; Saqib, Muhammad; Schutzer, Steven E.; Keim, Paul S; Nierman, William C.
In: Genome Biology and Evolution, Vol. 2, No. 1, 2010, p. 102-116.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Continuing evolution of Burkholderia mallei through genome reduction and large-scale rearrangements
AU - Losada, Liliana
AU - Ronningf, Catherine M.
AU - Deshazer, David
AU - Woods, Donald
AU - Fedorova, Natalie
AU - Kim, H. Stanley
AU - Shabalina, Svetlana A.
AU - Pearson, Talima R
AU - Brinkac, Lauren
AU - Tan, Patrick
AU - Nandi, Tannistha
AU - Crabtree, Jonathan
AU - Badger, Jonathan
AU - Beckstrom-Sternberg, Stephen M
AU - Saqib, Muhammad
AU - Schutzer, Steven E.
AU - Keim, Paul S
AU - Nierman, William C.
PY - 2010
Y1 - 2010
N2 - Burkholderia mallei (Bm), the causative agent of the predominately equine disease glanders, is a genetically uniform species that is very closely related to the much more diverse species Burkholderia pseudomallei (Bp), an opportunistic human pathogen and the primary cause of melioidosis. To gain insight into the relative lack of genetic diversity within Bm, we performed whole-genome comparative analysis of seven Bm strains and contrasted these with eight Bp strains. The Bm core genome (shared by all seven strains) is smaller in size than that of Bp, but the inverse is true for the variable gene sets that are distributed across strains. Interestingly, the biological roles of the Bm variable gene sets are much more homogeneous than those of Bp. The Bm variable genes are found mostly in contiguous regions flanked by insertion sequence (IS) elements, which appear to mediate excision and subsequent elimination of groups of genes that are under reduced selection in the mammalian host. The analysis suggests that the Bm genome continues to evolve through random IS-mediated recombination events, and differences in gene content may contribute to differences in virulence observed among Bm strains. The results are consistent with the view that Bm recently evolved from a single strain of Bp upon introduction into an animal host followed by expansion of IS elements, prophage elimination, and genome rearrangements and reduction mediated by homologous recombination across IS elements.
AB - Burkholderia mallei (Bm), the causative agent of the predominately equine disease glanders, is a genetically uniform species that is very closely related to the much more diverse species Burkholderia pseudomallei (Bp), an opportunistic human pathogen and the primary cause of melioidosis. To gain insight into the relative lack of genetic diversity within Bm, we performed whole-genome comparative analysis of seven Bm strains and contrasted these with eight Bp strains. The Bm core genome (shared by all seven strains) is smaller in size than that of Bp, but the inverse is true for the variable gene sets that are distributed across strains. Interestingly, the biological roles of the Bm variable gene sets are much more homogeneous than those of Bp. The Bm variable genes are found mostly in contiguous regions flanked by insertion sequence (IS) elements, which appear to mediate excision and subsequent elimination of groups of genes that are under reduced selection in the mammalian host. The analysis suggests that the Bm genome continues to evolve through random IS-mediated recombination events, and differences in gene content may contribute to differences in virulence observed among Bm strains. The results are consistent with the view that Bm recently evolved from a single strain of Bp upon introduction into an animal host followed by expansion of IS elements, prophage elimination, and genome rearrangements and reduction mediated by homologous recombination across IS elements.
KW - Bacterial evolution
KW - Bacterial virulence
KW - Comparative genomics
KW - Genome erosion
UR - http://www.scopus.com/inward/record.url?scp=77955709379&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77955709379&partnerID=8YFLogxK
U2 - 10.1093/gbe/evq003
DO - 10.1093/gbe/evq003
M3 - Article
C2 - 20333227
AN - SCOPUS:77955709379
VL - 2
SP - 102
EP - 116
JO - Genome Biology and Evolution
JF - Genome Biology and Evolution
SN - 1759-6653
IS - 1
ER -