title: Targeted expression of Cre recombinase provokes placental-specific DNA recombination in transgenic mice.
abstract: BACKGROUND
  Inadequate placental development is associated with a high incidence of early embryonic lethality and serious pregnancy disorders in both humans and mice. However, the lack of well-defined trophoblast-specific gene regulatory elements has hampered investigations regarding the role of specific genes in placental development and fetal growth.
  
  
  RESULTS
  By random assembly of placental enhancers from two previously characterized genes, trophoblast specific protein α (Tpbpa) and adenosine deaminase (Ada), we identified a chimeric Tpbpa/Ada enhancer that when combined with the basal Ada promoter provided the highest luciferase activity in cultured human trophoblast cells, in comparison with non-trophoblast cell lines. We used this chimeric enhancer arrangement to drive the expression of a Cre recombinase transgene in the placentas of transgenic mice. Cre transgene expression occurred throughout the placenta but not in maternal organs examined or in the fetus.
  
  
  CONCLUSIONS
  In conclusion, we have provided both in vitro and in vivo evidence for a novel genetic system to achieve placental transgene expression by the use of a chimeric Tpbpa/Ada enhancer driven transgene. The availability of this expression vector provides transgenic opportunities to direct the production of desired proteins to the placenta.
authors.affiliation: Department of Biochemistry, Texas A&M Health Science Center, Houston, Texas, United States of America.
authors.forename: Cissy Chenyi
authors.initials: CC
authors.lastname: Zhou
authors.forename: Jiang
authors.initials: J
authors.lastname: Chang
authors.forename: Tiejuan
authors.initials: T
authors.lastname: Mi
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Abbasi
authors.forename: Dongmin
authors.initials: D
authors.lastname: Gu
authors.forename: Le
authors.initials: L
authors.lastname: Huang
authors.forename: WenZheng
authors.initials: W
authors.lastname: Zhang
authors.forename: Rodney E
authors.initials: RE
authors.lastname: Kellems
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schwartz
authors.forename: Yang
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000243:Adenosine Deaminase / Q000235:genetics; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics*; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D018390:Gene Targeting; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D019426:Integrases / Q000378:metabolism*; D008156:Luciferases / Q000235:genetics; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009928:Organ Specificity / Q000235:genetics; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics*; D014158:Transcription, Genetic; D019076:Transgenes / Q000235:genetics; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D011257:Pregnancy Proteins; C558404:Tpbpa protein, mouse; D004247:DNA; D008156:Luciferases; C045073:Cre recombinase; D019426:Integrases; D000243:Adenosine Deaminase