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Updated: Aug 23, 2026

Laser-assisted Cytoplasmic Microinjection in Livestock Zygotes
Published on: October 5, 2016
Genome multiplication is a generalised phenomenon in placentomal and interplacentomal trophoblast giant cells in
Karl Klisch1, Preben D Thomsen, Vibeke Dantzer
1Microscopical Anatomy, Medical School of Hannover, Hannover, Germany. klisch.karl@mh-hannover.de
Abstract:
The frequency of polyploidisation in bovine binucleate trophoblast giant cells (TGC) from placentomes (PL) and the interplacentomal allantochorion (AL) of six male fetuses with a crown-rump length between 3.5 and 103 cm was determined by in situ hybridisation with a chromosome-7-specific probe, using a probe specific for the Y chromosome to distinguish between maternal and fetal nuclei. The results showed that polyploid nuclei were essentially always of fetal origin. The frequency of tetraploid nuclei varied between 3% and 15% in both the placentomal and interplacentomal samples, with mean frequencies of 8.8% and 10.0% respectively. Octoploid nuclei were observed with a mean frequency of 1.1% in the interplacentomal samples, but were absent in samples from placentomes. Subsequent determination of nuclear DNA content by cytophotometric measurement of Feulgen-stained nuclei revealed that the frequency of nuclei with an 8C DNA content was several fold higher (AL 5.4%; PL 7.8%) than the frequency of octoploidy, suggesting that tetraploid TGC cells are arrested in the G2 phase of the cell cycle.
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