Effects of Warming Rate and Degenerated Blastomere(s) on Development of Frozen and Thawed Mouse Embryos

Kim,  Moon-Kyoo; Lee,  Ho-Joon; Lee,  Seung-Jae; Jun,  Jong-Young

Original Article

Korean Journal of Fertility and Sterility 1987;14(1):51-59.

Moon-Kyoo Kim¹, Ho-Joon Lee¹, Seung-Jae Lee², Jong-Young Jun²

¹Department of Biology, College of Natural Sciences, Hanyang University
²IVF Laboratory, Department of ObstetrU:s and Gynecology, Cheil General Hospital

냉동.해빙한 생쥐배아의 발생에 미치는 해빙속도와 퇴화할구의 영향

김문규¹, 이호준¹, 이승재², 전종영²

¹한양대학교 자연과학대학 생물학과
²제일병원 산부인과 체외수정연구실

Abstract

The present experiments have been bone to verify the effects of the warming rate and the degenerated blastomere(s) on further development of the frozen and thawed 4- and 8-cell mouse embryos. The embryos obtained from the mouse superovulated and mated were frozen in the solution of 15M DMSO in PBS containing 10% FCS at a slowly cooling rate($0.3^{\circ}C/min$). Two methods of warming slowly($8^{\circ}C/min$) and quickly ($450^{\circ}C/min$) were applied for thawing embryos. The thawed embryos were grouped according to the number of healthy blastomere(s) in the embryos. Some of the embryos were eliminated their degenerated blastomere(s) by means of a micromanipulation technique. The embryos were examined their developmental phases after 48 or 72 hrs incubation. The rates of blastocyst development from the frozen and thawed 4- and 8-cell embryos were 72.7% and 73.5%, respectively in case of thawing slowly, and were 78.9% and 80.0%, respectively in case of thawing quickly. The rate in case of thawing quickly was significantly higher than that in case of thawing slowly. The rates of blastocyst development from the frozen and thawed 4- and 8-cell embryos eliminated their degenerated blastomere(s) increased 5.9% and 24.4%, respectively compared with those of control groups not eliminated. The more number of degenerated blastomere(s) were eliminated from the embryos, the higher rate of blastocyst development was shown. It may be concluded from the results that the quickly thawing method is better for increasing survival rate than the slowly thawing one, and that the degenerated blastomere(s) in the frozen and thawed embryos affects as an interfering factor for further development of the embryos.