Objective:To identify the differentially expressed proteins of 2

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8-tetrachloro-dibenzo-p-dioxin(2

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8-TCDD)induced cleft palate by using two-dimensional gel electrophoresis(2-DE) and mass spectrometry.Methods:On E12

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8-TCDD(64 μg/kg) and corn oil(control group) were administered to time-pregnant C57BL/6J mice.Anatomical and histological changes of palates in mouse fetuses were studied on E18.Total proteins were extracted from palate tissue of fetuses from both groups.The total proteins were separated by two-dimensional gel electrophoresis.The differentially expressed proteins between the two groups were compared using image analysis software.The peptide mass fingerprintings(PMF) was acquired after matrix assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS)and the proteins were identified by data searching in the Mascot database.The expression of the differential protein was confirmed by immunohistochemistry.Results:Incidence of cleft palate in the experimental group was 100%.Comparative analysis of 2-DE maps revealed 34 differentially expressed proteins between the two groups.Ten differential proteins were further identified by mass spectrometry

of which 7 showed significantly higher volumes in experimental group than in control group and 3 showed significantly higher volumes in control group than in experimental group.Peroxiredoxin 1 protein and guanine nucleotide dissociation inhibitors were up-regulated in experimental group.Conclusion:Up-regulated peroxiredoxin 1 protein and guanine nucleotide dissociation inhibitors may be associated with cleft palate in mice induced by 2

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8-TCDD.