Identification of Bacillus anthracis specific chromosomal sequences by suppressive subtractive hybridization.
BACKGROUND
Bacillus anthracis, Bacillus thuringiensis and Bacillus cereus are closely related members of the B. cereus-group of bacilli. Suppressive subtractive hybridization (SSH) was used to identify specific chromosomal sequences unique to B. anthracis.


RESULTS
Two SSH libraries were generated. Genomic DNA from plasmid-cured B. anthracis was used as the tester DNA in both libraries, while genomic DNA from either B. cereus or B. thuringiensis served as the driver DNA. Progressive screening of the libraries by colony filter and Southern blot analyses identified 29 different clones that were specific for the B. anthracis chromosome relative not only to the respective driver DNAs, but also to seven other different strains of B. cereus and B. thuringiensis included in the process. The nucleotide sequences of the clones were compared with those found in genomic databases, revealing that over half of the clones were located into 2 regions on the B. anthracis chromosome.


CONCLUSIONS
Genes encoding potential cell wall synthesis proteins dominated one region, while bacteriophage-related sequences dominated the other region. The latter supports the hypothesis that acquisition of these bacteriophage sequences occurred during or after speciation of B. anthracis relative to B. cereus and B. thuringiensis. This study provides insight into the chromosomal differences between B. anthracis and its closest phylogenetic relatives.
Dwyer
Kathleen G
KG
Loyola Hall of Science, University of Scranton, Scranton, Pennsylvania 18510, USA. kgd301@scranton.edu
Lamonica
Janine M
JM
Schumacher
Jennifer A
JA
Williams
Leanne E
LE
Bishara
Joanne
J
Lewandowski
Anna
A
Redkar
Rajendra
R
Patra
Guy
G
DelVecchio
Vito G
VG
D001408:Bacillus anthracis / Q000145:classification / Q000235:genetics*; D001409:Bacillus cereus / Q000235:genetics; D001413:Bacillus thuringiensis / Q000235:genetics; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics; D015698:Genomic Library; D009693:Nucleic Acid Hybridization / Q000379:methods*; D013045:Species Specificity
D004269:DNA, Bacterial; D015252:Deoxyribonucleases, Type II Site-Specific; C040158:GTAC-specific type II deoxyribonucleases