Ribosomal dna copy number variations in maternal and fetal cells in normal pregnancy and missed miscarriage

Objective. To analyze the hypothesis of the effect of rDNA copy number in the maternal and fetal genomes on embryogenesis. Patients and methods. The study included 35 patients: 20 patients with missed miscarriage at a gestational age of 5-13 weeks. An anembryonic pregnancy was registered in 5 of them, and the remaining 15 had missed miscarriage of unknown reason (group I); 5 patients underwent termination for medical reasons (teratogenic effects) at 13-21 weeks of gestation (group II). The control group consisted of 10 healthy patients who underwent induced abortion on their own accord at 8-11 weeks of gestation (group III). The embryonic tissue (sample E), decidual membrane tissue (sample D) and blood from the median cubital vein (sample C) were collected from all patients during the operation. DNA isolation was performed by organic solvent extraction. The number of rDNA copies in DNA was determined by non-radioactive quantitative hybridization (NQH). Results. The rDNA content was similar in blood cells and decidual cells of the same female organism. Missed miscarriage was associated with a pronounced imbalance in rDNA content in the embryonic and maternal genomes. In most cases, the embryonic genome contained significantly fewer rDNA copies than the maternal genome and the genomes of other embryos that did not spontaneously abort. Conclusion. The determination of rDNA copy number in the genomes of potential parents and subsequent modeling of rDNA copy number in the embryo may help in identifying the causes of infertility in couples. © 2024, Dynasty Publishing House. All rights reserved.