title: Transcriptome analysis in blastocyst hatching by cDNA microarray.
abstract: BACKGROUND
  Hatching is an important process for early embryo development, differentiation and implantation. However, little is known about its regulatory mechanisms. By integrating the technologies of RNA amplification and cDNA microarrays, it has become possible to study the gene expression profile at this critical stage.
  
  
  METHODS
  Pre-hatched and hatched ICR mouse embryos (25 blastocysts in each group were used in the triplicate experiments) were collected for RNA extraction, amplification, and microarray analysis (the mouse cDNA microarray, 6144 genes, including expressed sequence tags).
  
  
  RESULTS
  According to cDNA microarray data, we have identified 85 genes that were expressed at a higher level in hatched blastocyst than in pre-hatched blastocysts. In this study, 47 hatching-related candidate genes were verified via re-sequencing. Some of these genes have been selected and confirmed by real-time quantitative RT-PCR. These hatching-specific genes were also expressed at a lower level in the delayed growth embryos (morula or blastocyst without hatching at day 6 post hCG). These genes included: cell adhesion and migration molecules [E-cadherin, neuronal cell adhesion molecule (NCAM), lectin, galactose binding, soluble 7 (Lgals7), vanin 3 and biglycan], epigenetic regulators (Dnmt1, and SIN3 yeast homolog A), stress response regulators (heme oxygenase 1) and immunoresponse regulators [interleukin (IL)-2-inducible T-cell kinase, IL-4R, interferon-gamma receptor 2, and neurotrophin]. The immunostaining of E-cadherin and NCAM showed strong and specific localization in hatched blastocyst.
  
  
  CONCLUSIONS
  This work provides important information for studying the mechanisms of blastocyst hatching and implantation. These hatching-specific genes may have potential as new drug targets for controlling fertility.
authors.affiliation: Institute and Department of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Huei-Wen
authors.initials: HW
authors.lastname: Chen
authors.forename: Jeremy J W
authors.initials: JJ
authors.lastname: Chen
authors.forename: Sung-Liang
authors.initials: SL
authors.lastname: Yu
authors.forename: Han-Ni
authors.initials: HN
authors.lastname: Li
authors.forename: Pan-Chyr
authors.initials: PC
authors.lastname: Yang
authors.forename: Ching-Mao
authors.initials: CM
authors.lastname: Su
authors.forename: Heng-Kien
authors.initials: HK
authors.lastname: Au
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Chang
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Chien
authors.forename: Chieh-Sheng
authors.initials: CS
authors.lastname: Chen
authors.forename: Chii-Ruey
authors.initials: CR
authors.lastname: Tzeng
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D010064:Embryo Implantation / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D021141:Nucleic Acid Amplification Techniques; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction