title: Gene-expression profile analysis in the mid-gestation human intestine discloses greater functional immaturity of the colon as compared with the ileum.
abstract: OBJECTIVE
  The occurrence of many neonatal inflammatory intestinal diseases in preterm infants highlights the susceptibility of the immature intestine to responding inadequately to nutrients and microbes. A better understanding of functional intestinal development is essential for the design of optimal treatments ensuring survival and growth of premature infants. The purpose of this study was to evaluate the gene expression profiles of the human ileum and colon at mid-gestation because these 2 segments are considered to be similar at this stage and are the sites of the most frequent pathologies in preterm infants.
  
  
  METHODS
  We compared the gene-expression profiles of human fetal small and large intestines using a cDNA microarray and analyzed the data with Ingenuity Pathway Analysis software.
  
  
  RESULTS
  We found that a significant proportion of the genes was differentially expressed in the 2 segments. Gene cluster analysis revealed an even higher level of transcriptional dissimilarity at the functional level. For instance, segment-specific/overexpressed gene clusters in the ileum included genes involved with amino acid, vitamin, and mineral metabolism, reflecting the higher level of maturity of the small intestine as compared with the colon in which genes involved with cell cycle, cell death, and cell signaling were the predominant clusters of genes expressed.
  
  
  CONCLUSIONS
  Functional clustering analysis of the differentially expressed genes revealed important functional differences between the 2 segments and a relative immaturity of the colon, suggesting that already at mid-gestation, the 2 intestinal segments should be considered as 2 distinct organs.
authors.affiliation: Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Tremblay
authors.forename: Emanuela
authors.initials: E
authors.lastname: Ferretti
authors.forename: Corentin
authors.initials: C
authors.lastname: Babakissa
authors.forename: Ernest G
authors.initials: EG
authors.lastname: Seidman
authors.forename: Emile
authors.initials: E
authors.lastname: Levy
authors.forename: Daniel
authors.initials: D
authors.lastname: Ménard
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beaulieu
mesh_terms: D002453:Cell Cycle / Q000235:genetics; D016923:Cell Death / Q000235:genetics; D016000:Cluster Analysis; D003106:Colon / Q000196:embryology*; D018076:DNA, Complementary; D015870:Gene Expression / Q000502:physiology*; D020869:Gene Expression Profiling / Q000379:methods; D006801:Humans; D007082:Ileum / Q000196:embryology*; D046228:Microarray Analysis; D015398:Signal Transduction / Q000235:genetics
chemical_list: D018076:DNA, Complementary