title: Quantitative analysis of miRNA expression in several developmental stages of human livers.
abstract: OBJECTIVE
  miRNAs have been found to regulate gene expression at a posttranscriptional level in cells. Studies have shown that expression of miRNAs is tissue-specific and developmental stage-specific. The mechanism behind this could be explained by miRNA pathways.
  
  
  METHODS
  We introduce the identification of miRNAs from two human fetal liver cDNA libraries by a cloning protocol. The miRNAs detected were then analyzed in a chorionic villus tissue and four liver tissues using real-time polymerase chain reaction.
  
  
  RESULTS
  After sequencing and database searching, a total of 42 miRNAs in two fetal livers were detected. Quantitative analysis showed that they have higher general expression in the livers of the fetal period than the adult period, and furthermore the expression levels of the miRNAs during the fetal period were dynamically changed.
  
  
  CONCLUSIONS
  Our results indicate that a special group of miRNAs may play an important role in human fetal liver development, while their roles in the adult livers are limited.
authors.affiliation: Departments of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.forename: Wanjiang
authors.initials: W
authors.lastname: Zeng
authors.forename: Yiwu
authors.initials: Y
authors.lastname: Zhou
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Ingvarsson
authors.forename: Huiping
authors.initials: H
authors.lastname: Chen