Genetic variations in the pgm locus among natural isolates of Yersinia pestis.
A PCR-based screening method was used to study the genetic variations of the pgm locus among natural isolates of Yersinia pestis from China. Our results indicate that genetic variations in the pgm locus are well correlated with biovars of Y. pestis and plague foci, suggesting that the pgm locus plays a role in Y. pestis adaptation to its environment. The gene encoding two-component regulatory system sensor kinase became a pseudogene in all strains of biovar Orientalis due to a thymidine deletion, while it is intact in all the strains of the other biovars. Only strains from Foci H and L are the same as Yersinia pseudotuberculosis in that they have an intact transmembrane helix in the sensor kinase protein, which is lost in all the other strains because of the 18 bp in-frame deletion. The IS100 element that flanks the 39 terminus of the pgm locus was inserted into the chromosome during the within-species microevolution of Y. pestis, which is absent in strains from Foci G, H and L and also in Y. pseudotuberculosis. This fact indicates that the strains from these three foci are of an older lineage of Chinese Y. pestis. It is this IS100 element's absence that maintained high stability of the pgm locus in the Y. pestis strains from these three foci. The IS285 element insertion in the pigmentation segment and the IS100 element insertion in the downstream flanking region of the pgm locus are only present in strains from Foci H and L. The flanking region outside the 59 terminus of the upstream IS100 element is identical in the strains from these two foci, which is different in the other strains. All of these unique characteristics suggest that they are of a special lineage of Chinese Y. pestis.
Tong
Zong-Zhong
ZZ
Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, P. R. China.
Zhou
Dong-Sheng
DS
Song
Ya-Jun
YJ
Zhang
Ling
L
Pei
Decui
D
Han
Yan-Ping
YP
Pang
Xin
X
Li
Min
M
Cui
Bai-Zhong
BZ
Wang
Jin
J
Guo
Zhao-Biao
ZB
Qi
Zhi-Zhen
ZZ
Jin
Li-Xia
LX
Zhai
Jun-Hui
JH
Du
Zong-Min
ZM
Wang
Xiao-Yi
XY
Wang
Jian
J
Huang
Pei-Tang
PT
Yang
Huan-Ming
HM
Yang
Rui-Fu
RF
D000483:Alleles; D001483:Base Sequence; D002681:China; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D014644:Genetic Variation; D042822:Genomic Instability; D044404:Genomic Islands; D006801:Humans; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D015010:Yersinia pestis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D015011:Yersinia pseudotuberculosis / Q000145:classification / Q000235:genetics
D004251:DNA Transposable Elements; D004269:DNA, Bacterial