Sensitivity of early mouse embryos to [3H]thymidine

Effect of polyamine limitation on DNA synthesis and development of mouse preimplantation embryos in vitro

“…Aphidicolin is a specific inhibitor of the 'replicative' DNA polymerase- (Hübscher, 1983), whereas arabinosylcytosine and hydroxyurea are the drugs that have been claimed to inhibit primarily semiconservative DNA replication (Furth & Cohen, 1968;Ingaki, Nakamura & Wakisaka, 1969;Cleaver, 1969). It has been claimed that tritiated thymidine might interfere with the in-vitro development of mouse embryos, due to their sensitivity to irradiation from ß-emitters (Macqueen, 1979;Spindle, Wu & Pedersen, 1982 ( -methylornithine and -DFMO) demonstrates that the synthesis of spermidine and spermine is critical at this early stage of development. MGBG seems to induce a metabolic quiescence of the embryos with regard to both DNA replication and cell proliferation.…”

Determination and synchronisation of G1-phase of the cell cycle in 2- and 4-cell mouse embryos

“…In a study on the effect of [ 3 H]thymidine on mouse embryo development, Spindle et al (1982) found that the exposure time needed to reveal incorporated [ 3 H]thymidine in mouse embryos was related to the developmental stage. In the present study, we labelled mouse embryos at the 4-cell, 8-cell, morula and blastocyst stages with different con- Spindle et al (1982) proposed that the low ability of early embryos to incorporate [ 3 H]thymidine may be attributed to decreased membrane penetrability or interference of the endogenous thymidine pool with incorporation of exogenous thymidine. It has been shown that the duration of embryo cell cycles depends on the length of S-phase, because the length of G1-phase in embryo cells is very short, and some even cannot be detected.…”

Effects of cell cycle specific exposure to 3 H-thymidine or 3 H-arginine on development and cell proliferation of mouse embryos

“…That the high risk exerted by tritium after incorporation into the cell is real and not just theoretically to be expected has been shown in numerous studies of preimplantation embryos [1][2][3][4][5][6][7][8][9][10]. Particularly dangerous are tritiated agents that are incorporated into nuclear compounds either almost exclusively ( 3 H-thymidine into DNA) or predominantly ( 3 H-arginine into histones).…”