Effect Of ROS On Cell Number And Cleavage Index Of Mouse Embryo

To make clear the mechanism of early embryo development block in vitro of mammalian, people searched the reason in the inner embryo and outer circumstance constantly. At present time people has found that various oxidants exist in injured cells, including peroxide and other free radical (eg: peroxide anion and hydroxide radical ion); these ROS also exist in abnormal cells arose from cell cleavage block and cell function loss.This experiment object was 1-cell embryo of KUNMING mouse , ROS was added in different developmental phases through basal medium with CZB medium, cultured to morulae, early blastula, blastula and the hatching of blastula, observed the change of cell number and cleavage index of embryo. On the level of cell we further proved whether exogenous ROS had effect on mammalian early embryo.The experiment has shown: 1,The average cell number of each morulae, early blastula, blastula and the hatching of blastula development in vivo were 22.54, 35.49, 36.93, 46.78, its cleavage index were 5.85, 4.64, 2.16, 4.96; The average cell number of each morulae, early blastula, blastula and the hatching of blastula development with CZB medium in vitro were 18.03, 25.30, 29.13, 45.68, its cleavage index were 6.26, 5.08, 2.77, 3.03. By statistic analysis, there were significant differences with the average cell number of each morulae, early blastula and blastula between in vivo and in vitro, there were no differences with the hatching of blastula between in vivo and in vitro. Furthermore, the cleavage index of various embryos phases were no differences between in vivo and in vitro.2,The average cell number of each embryo were significant differences between 12-24 hr and 36-48 hr treatment and 0-72 hr treatment of early blastula; the cleavage index of each embryo were significant differences between 0-12hr and 24-36 hr treatment and 0-72 hr treatment of the hatching of blastula; embryo cell number and cleavage of other treatments were no differences. These showed that embryo was sensitivity to exogenous H2O2 in 2-cell embryo(0-12 hr treatment) cultured in vitro, development block occurred more easily. But embryo got through 2-cell block after H2O2 treatment occurred compensatory growth in later development, there were no differences with the embryo cell number and the cleavage index compared with normal developmental embryo.