The Changes And Differences In Expression Of Fibroblast Growth Factor 3 During Development Of BALB/c Mouse Palate And Cleft Palate

Objective:Retinoic acid(RA)was used to induce cleft palate model in BALB/c mice and to observe the changes and differences in expression of Fibroblast Growth Factor 3(FGF3)during development of normal palate and cleft palate and to explore its role in palate development.Methods:The study selected 48(36 female and 12 male mice)SPF BALB/c mice.female ones were housed overnight with male ones according to the proportion of 3 to 1.Pregnant mice were randomly divided into two groups,each group contained 18 mice.The experimental group was treated with a single dose of RA(50mg/kg)on gestation day(GD)10 while the control group was treated with the equivalent volume of corn oil(5ml/kg)alone.Every 3mice were killed in both two groups on GD 12,13,14,15 respectively.Fetal mice were took out and made the head specimens.Observed the development of palate and cleft palate,immunohistochemical staining was used to detect the expression of FGF3 and the differences between two groups.Remaining 12 pregnant mice were killed on GD 17.Fetal mice were removed and observed for the conclusion of the rate of deformity.Results:1.The study obtained 75 fetal mice,among which 36 mice in RA group and 31 showed cleft palate,the incidence rate was 86%;39 mice in control group and no individuals with cleft palate.2.The HE staining showed: the palatal developed normally in control group;in RA group,tongue declined slow and palatal process had difficulty in uplifting on GD 14,palatal process was thin and unable to fuse on GD 15.3.The immunohistochemical staining showed: FGF3 was expressed only in mesenchymal cytoplasm.In control group,FGF3 was all positive detected and the staining of GD13 and GD14 was deeper;no obvious staining of GD14 was found in RA group and the staining of remaining days were relatively shallow compared with the control group.Expression of FGF3 in RA group was lower than control group,the difference was statistically significant(P < 0.05).There were both significant differences of OD among two groups(P < 0.05).In control group FGF3 was strongest expression in GD14,showing a trend of rising and then descending.The strongest expression of FGF3 in RA group was in GD12,while the trend was reverse relative to that in control group.Conclusions:FGF3 was positive expressed in EPM cells from sprout to fusion period of development of palata,especially stronger in the uplift and horizontal growth stages.The expression level of FGF3 in the development of the cleft palate was lower than normal palatal process.It could be assumed that FGF3 promotes the proliferation of EPM cells,which is associated with the development of palatal processes.