title: Identification by cDNA cloning of abundant sRNAs in a human-avirulent Yersinia pestis strain grown under five different growth conditions.
abstract: OBJECTIVE
  sRNA regulation is supposedly involved in the stress response of a pathogen during infection. Yersinia pestis, the etiologic agent of plague, must encounter temperature and microenvironment changes, given its lifestyle. Here, we used the cDNA cloning approach to discover full-length sRNA candidates that are highly expressed in Y. pestis under five different growth conditions.
  
  
  METHODS
  The cDNA cloning approach was improved by combining the traditional cDNA library construction with the prevalent rapid amplification of cDNA ends and RNA size selection techniques.
  
  
  RESULTS
  In total, 43 RNA species, including six previously annotated sRNAs, were identified. Of these, 25 sRNAs were encoded on the antisense strand of the annotated genes. Interestingly, two of these sRNAs were found on the complementary strand of noncoding RNAs. In addition, eight novel sRNAs encoded in the intergenic regions were also revealed. Ten sRNA candidates chosen for the northern blot analysis were successfully detected. Analysis of the expression patterns of 29 candidate sRNAs showed that 24 sRNAs are highly abundant in Y. pestis upon entry into the stationary growth phase.
  
  
  CONCLUSIONS
  Our preliminary attempt at screening the novel sRNA candidates will lay the foundation for understanding the roles of sRNAs in Y. pestis physiology and pathogenesis.
authors.affiliation: State Key Laboratory of Pathogen & Biosecurity, Beijing Institute of Microbiology & Epidemiology, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Qu
authors.forename: Lijun
authors.initials: L
authors.lastname: Bi
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Ji
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Deng
authors.forename: Hongtai
authors.initials: H
authors.lastname: Zhang
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Yan
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Aqian
authors.initials: A
authors.lastname: Li
authors.forename: Xinxiang
authors.initials: X
authors.lastname: Huang
authors.forename: Ruifu
authors.initials: R
authors.lastname: Yang
authors.forename: Yanping
authors.initials: Y
authors.lastname: Han
mesh_terms: D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D058977:Molecular Sequence Annotation; D010930:Plague / Q000382:microbiology*; D012329:RNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D022661:RNA, Untranslated / Q000235:genetics* / Q000378:metabolism; D015010:Yersinia pestis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D018076:DNA, Complementary; D012329:RNA, Bacterial; D022661:RNA, Untranslated