Abstract: Purpose: To investigate the effect of Vit. A deficiency on Hox3.5 mRNA expression and development of mouse embryos. Methods: Sixty Kunming female mice were divided in to four groups: normal control group N ( 4 000 IU Vit.A/kg diet),Vit.A deficiency group A ( 0 IU Vit.A/kg diet)、Vit.A-supplement after 0d.p.c (day post coitus), group B and Vit,A-supplement after 7 d.p.c group C (B、C were fed 0 IU Vit.A/kg diet before crossover, B was fed 10 000 IU Vit.A/kg diet after 0 d.p.c and C was fed 10 000 IU Vit.A/kg diet after 7 d.p.c.). On the 12th day p.c. pregnant mice in every group were killed and the uteri were dissected and the mouse embryos were taken out immediately. Meanwhile, blood samples were taken from pregnant mice for the determination of serum Vit.A. In situ hybridization was used to determine Hox-3.5 mRNA expression in the mouse embryos by digitoxin-labeled cDNA probes. Results: Hox-3.5 mRNA expression in the embryos of group A and C decreased significantly as compared with group N and B (P<0.01， P<0.05),and there was no difference between group B and group N. The level of Hox-3.5 mRNA expression in group C was higher than that of group A, but still lower than group N. Vit.A-deficiency(A) was significantly lower than that of group A and abnormal development of the skeleton existed. Moreover, encephalocele and micro kidney were found. Conclusion: Vit.A may regulate Hox gene expression in transcription level and may influence the development and growth of embryos.

Key words: Vitamin A deficieny, Hox-3.5 mRNA expression, mouse embryos