Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-13T11:28:57.421Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  19 August 2002

Yuansong Yu
Affiliation:
Department of Biotechnology, Northeast Agricultural University, Harbin 150030, China
Ping Xia
Affiliation:
Department of Obstetrics and Gynecology, College of Medicine, University of Arizona, Tucson, Arizona, USA
Shufent Li
Affiliation:
Department of Biotechnology, Northeast Agricultural University, Harbin 150030, China
Yunqin Yan
Affiliation:
Department of Biotechnology, Northeast Agricultural University, Harbin 150030, China
Jinghe Tan
Affiliation:
Department of Biotechnology, Northeast Agricultural University, Harbin 150030, China College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai An 271018, China

Abstract

Incorporation of [3H]thymidine at different concentrations into mouse embryos at early developmental stages was determined by autoradiography. Methods to synchronise the G1-phase of mouse 2- and 4-cell embryos were also investigated. The results showed that the ability of embryos to incorporate [3H]thymidine increased with development. Embryos at the 4-cell stage were not labelled when the concentration of [3H]thymidine was lower than 5 μCi/ml, whereas the nuclei of embryos at morula and blastocyst stages began to show silver grains at a concentration of 0.1 μCi/ml of [3H]thymidine. After 2- and 4-cell mouse embryos were synchronised at the onset of G1-phase by treatment with low temperature or nocodazole, and DNA synthesis was detected by autoradiography, the duration of G1-phase was estimated. The result showed that 43% of the 2-cell embryos had a G1-phase of ≤ 1 h, 22% had a G1-phase of ≤ 2 h, 22% had a G1-phase of ≤ 3 h and 13% had a G1-phase of ≤ 4 h. The G1-phase in 85% of the 4-cell embryos was ≤ 3 h, that in 8% of embryos was ≤ 4 h and that in 7% of embryos was ≤ 5 h. The toxicity of nocodazole on mouse embryo development was assessed based on both blastocyst formation and the number of blastomeres, and the results indicated that the effect of nocodazole on embryo development and cell cycle block was dose-dependent. The minimum concentration of nocodazole for metaphase block of mouse late 2-cell embryos was 0.05 μM, and the appropriate concentrations which did not impair development were 0.05-0.5 μM.

Type
Research Article
Copyright
2002 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)