Comparison of genome degradation in Paratyphi A and Typhi, human-restricted serovars of Salmonella enterica that cause typhoid.
Salmonella enterica serovars often have a broad host range, and some cause both gastrointestinal and systemic disease. But the serovars Paratyphi A and Typhi are restricted to humans and cause only systemic disease. It has been estimated that Typhi arose in the last few thousand years. The sequence and microarray analysis of the Paratyphi A genome indicates that it is similar to the Typhi genome but suggests that it has a more recent evolutionary origin. Both genomes have independently accumulated many pseudogenes among their approximately 4,400 protein coding sequences: 173 in Paratyphi A and approximately 210 in Typhi. The recent convergence of these two similar genomes on a similar phenotype is subtly reflected in their genotypes: only 30 genes are degraded in both serovars. Nevertheless, these 30 genes include three known to be important in gastroenteritis, which does not occur in these serovars, and four for Salmonella-translocated effectors, which are normally secreted into host cells to subvert host functions. Loss of function also occurs by mutation in different genes in the same pathway (e.g., in chemotaxis and in the production of fimbriae).
McClelland
Michael
M
Sidney Kimmel Cancer Center, 10835 Altman Row, San Diego, California 92121, USA. mmcclelland@skcc.org
Sanderson
Kenneth E
KE
Clifton
Sandra W
SW
Latreille
Phil
P
Porwollik
Steffen
S
Sabo
Aniko
A
Meyer
Rekha
R
Bieri
Tamberlyn
T
Ozersky
Phil
P
McLellan
Michael
M
Harkins
C Richard
CR
Wang
Chunyan
C
Nguyen
Christine
C
Berghoff
Amy
A
Elliott
Glendoria
G
Kohlberg
Sara
S
Strong
Cindy
C
Du
Feiyu
F
Carter
Jason
J
Kremizki
Colin
C
Layman
Dan
D
Leonard
Shawn
S
Sun
Hui
H
Fulton
Lucinda
L
Nash
William
W
Miner
Tracie
T
Minx
Patrick
P
Delehaunty
Kim
K
Fronick
Catrina
C
Magrini
Vincent
V
Nhan
Michael
M
Warren
Wesley
W
Florea
Liliana
L
Spieth
John
J
Wilson
Richard K
RK
D001483:Base Sequence; D019143:Evolution, Molecular; D015723:Gene Library; D014644:Genetic Variation; D040481:Genome Components / Q000235:genetics; D016680:Genome, Bacterial; D006801:Humans; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011544:Pseudogenes / Q000235:genetics; D012482:Salmonella paratyphi A / Q000235:genetics*; D012485:Salmonella typhi / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity