This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ozil, J. P. Search for Related Content PubMed PubMed Citation Articles by Ozil, J. P.

Production of identical twins by bisection of blastocysts in the cow

Summary. Day-8 embryos were recovered by a non-surgical method from superovulated crossbred heifers. Normal expanded blastocysts with a distinct inner cell mass and a trophoblast were released from the zona pellucida and bisected along a sagittal plane into two 'half' blastocysts. Each 'half' blastocyst was replaced in an empty zona pellucida and cultured for 2 h in B2 medium. After culture the 'half' blastocysts were directly transferred to recipient heifers via the cervix. From 11 blastocysts, 11 monozygotic 'half' blastocyst pairs were transferred to 11 recipients: 8 recipients became pregnant, 4 carried twins and one delivered a normal calf and an acardiacus amorphus monster consisting of disorganized embryonic tissues. A further 11 'half' blastocysts were transferred as singletons to 11 recipients. Five recipients were apparently pregnant at Day 42. One returned to oestrus at Day 45, 3 were carrying normal fetuses and 1 a pair of normal twin fetuses when slaughtered at Day 128.

It is concluded that even after the first irreversible cellular differentiation which occurs at the blastocyst stage it is still possible to produce identical cattle twins by bisection of the Day-8 blastocyst.

This article has been cited by other articles:

				C. Lorthongpanich, S.-H. Yang, K. Piotrowska-Nitsche, R. Parnpai, and A. W S Chan Development of single mouse blastomeres into blastocysts, outgrowths and the establishment of embryonic stem cells Reproduction, June 1, 2008; 135(6): 805 - 813. [Abstract] [Full Text] [PDF]

				S. M. Mitalipov, R. R. Yeoman, H.-C. Kuo, and D. P. Wolf Monozygotic Twinning in Rhesus Monkeys by Manipulation of In Vitro-Derived Embryos Biol Reprod, May 1, 2002; 66(5): 1449 - 1455. [Abstract] [Full Text]

				K. Yakin, S. Kahraman, and S. Comert Three blastocyst stage embryo transfer resulting in a quintuplet pregnancy: Case report Hum. Reprod., April 1, 2001; 16(4): 782 - 784. [Abstract] [Full Text] [PDF]

				J. Ozil and D Huneau Activation of rabbit oocytes: the impact of the Ca2+ signal regime on development Development, January 3, 2001; 128(6): 917 - 928. [Abstract] [PDF]

				E.S. Sills, M. Moomjy, N. Zaninovic, L. L. Veeck, M. McGee, G. D. Palermo, and Z. Rosenwaks Human zona pellucida micromanipulation and monozygotic twinning frequency after IVF Hum. Reprod., April 1, 2000; 15(4): 890 - 895. [Abstract] [Full Text] [PDF]