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Updated: Aug 13, 2026

Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Endoreduplication of the hyperhaploid maternal complement and abnormal pronuclear formation in a human zygote
Bernd Rosenbusch1, Birgitta Glaeser, Cosima Brucker
1Department of Gynecology and Obstetrics, Centre of Reproductive Medicine, University of Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany. bernd.rosenbusch@medizin.uni-ulm.de
Abstract:
We report the cytogenetic analysis of a tripronuclear zygote with two polar bodies observed after intracytoplasmic sperm injection. Rare previous investigations of this kind of zygote suggested a diploid or a hypotriploid chromosome constitution. In contrast, the present case turned out to be hypertriploid. Besides the haploid (23,Y) sperm chromosome set, there was a hyperdiploid endoreduplicated (end48,XX,+18,+18) maternal contribution. This zygote not only revealed a peculiar combination of different anomalies (hyperhaploidy of the female gamete, endoreduplication and abnormal pronuclear formation) but also indicates that endoreduplication may sporadically contribute to the generation of triploidy.
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