Effect of Intrauterine Malnutrition on Growth Characters and the DNA Methylation Level of H19 of Their Offspring / 医学研究杂志

ABSTRACT

Objective To establish a mouse model of intrauterine malnutrition to investigate the growth characters and the DNA methylation level of H19 of the offspring. Methods The pregnancy ICR mice were randomly divided into the food restricted group and the control group. The food eaten by each pregnant mouse every day was monitored from d0. 5 to d12. 5. The food restricted pregnancy mice were given half amount food of the daily consumption during d0. 5-d12. 5. The mice in control group were given the normal food. The pregnant mice of both groups of were given normal food after delivery. The number, birth weight and sex ratio of the offspring were calculated. Furthermore, the body weight of the offspring was monitored at different growth stages. The oocytes of female offspring mice were obtained to detect the DNA methylation level of H19. Results (1) Compared to normal feeding pregnant mice, mice with food restricted were small and less active, and even some of them were died before delivery. The incidence of premature birth was significantly increased (P ＜0. 05). The number of abortion, stillbirth pregnant mice in the food restriction group were more than that in the control group, but the difference was not statistically significant (P ＞ 0. 05). (2) There was no significant difference in the number of offspring between pregnancy mice with food restricted or normal food (P ＞ 0. 05). As well as the number of male offspring between the two groups (P ＞ 0. 05). However, the offspring of the food restricted pregnant mice showed significant low birth weight (P ＜ 0. 05). (3) At the age of 3 weeks, there was still a low body weight in the offspring of the food restricted pregnant mice, but the difference had no significant difference between groups (P ＞ 0. 05). After weaning at 3 weeks, the offspring of food restricted pregnant mice began the catch-up growth. At the age of 6 weeks, the body weight of offspring of food restricted pregnant mice was higher than that of the normal offspring, but the difference was not statistically significant (P ＞ 0. 05). During the period of 6-8 weeks, the weight of offspring of normal feed pregnancy mice was increased slowly. But the body weight of food restriction offspring mice was increased rapidly. At the age of 8 weeks, the body weight of offspring of food restricted group was significantly higher than that in control group (P ＜ 0. 05). (4) The methylation level of H19 in oocyte from offspring of food restricted pregnancy mice was normal. Conclusion Food restriction at pregnancy period not only affect the outcome of pregnancy, but also increased the rate of premature birth. The offspring of food restriction pregnancy mice showed low birth weight. Until the age of 6 weeks, the offspring of food restriction pregnancy mice had lower body weight compared with the offspring with normal feeding pregnancy mice. The offspring of food restriction pregnancy mice demonstrated obesity at 8 weeks. But the H19 methylation levels of oocytes from offspring of pregnancy mice with food restriction was normal.