title: [Effect of environmental contaminants on DNA methyltransferase activity of mouse preimplantation embryos].
abstract: OBJECTIVE
  To investigate the effect of environmental contaminants on development rate and DNA methyltransferase activity of preimplantation embryos.
  
  
  METHODS
  1-cell embryos were collected from oviduct, in vitro cultured to blastocyst stage in media with or without environmental contaminants. The development rate and DNA methyltransferase activity were determined.
  
  
  RESULTS
  The development rates of preimplantation embryos from 1-cell stage to blastocyst stage were not affected by the exposed compounds. However, 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) significantly increased the DNA methyltransferase activity, 2, 2', 3, 3' 4, 4'-polychlorinated biphenyl (PCB153) and diethylstilbestrol (DES) significantly decreased the DNA methyltransferase activity, while p, p'- dichlorodiphenel ethylene (DDE) and dibutyl phthalate (DBP) did not change the DNA methyltransferase activity significantly.
  
  
  CONCLUSIONS
  Exposure to TCDD, DES, and PCB 153 alters the DNA methyltransferase activity in early development stage, which may induce the change of methylation status of genes and affect the development in the later stage.
authors.affiliation: School of Public Health, Fudan University, Shanghai 200032, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wu
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Zhou
authors.forename: Seiichroh
authors.initials: S
authors.lastname: Ohsako
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects* / Q000201:enzymology; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000187:drug effects / Q000378:metabolism*; D004054:Diethylstilbestrol / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D051379:Mice; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011247:Pregnancy
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D004054:Diethylstilbestrol; D011078:Polychlorinated Biphenyls; D015254:DNA Modification Methylases; C014024:2,4,5,2',4',5'-hexachlorobiphenyl