Translator Disclaimer
1 August 2002 Aberrant Allocations of Inner Cell Mass and Trophectoderm Cells in Bovine Nuclear Transfer Blastocysts
Author Affiliations +

Abortions of nuclear transfer (NT) embryos are mainly due to insufficient placentation. We hypothesized that the primary cause might be the aberrant allocations of two different cell lineages of the blastocyst stage embryos, the inner cell mass (ICM) and the trophectoderm (TE) cells. The potential for development of NT embryos to blastocysts was similar to that for in vitro fertilized (IVF) embryos. No difference in the total cell number was detected between NT and IVF blastocysts, but both types of embryos had fewer total cells than did in vivo-derived embryos (P < 0.05). The NT blastocysts showed a higher ratio of ICM:total cells than did IVF or in vivo-derived embryos (P < 0.05). Individual blastocysts were assigned to four subgroups (I: <20%, II: 20–40%, III: 40–60%, IV: >60%) according to the ratio of ICM:total cells. Most NT blastocysts were placed in groups III and IV, whereas most IVF and in vivo-derived blastocysts were distributed in group II. Our findings suggest that placental abnormalities or early fetal losses in the present cloning system may be due to aberrant allocations of NT embryos to the ICM and TE cells during early development.

Deog-Bon Koo, Yong-Kook Kang, Young-Hee Choi, Jung Sun Park, Ha-Na Kim, Keon Bong Oh, Dong-Soo Son, Humdai Park, Kyung-Kwang Lee, and Yong-Mahn Han "Aberrant Allocations of Inner Cell Mass and Trophectoderm Cells in Bovine Nuclear Transfer Blastocysts," Biology of Reproduction 67(2), 487-492, (1 August 2002).
Received: 31 December 2001; Accepted: 1 February 2002; Published: 1 August 2002

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top