CooperGenomics, Livingston New Jersey, USA.
CooperGenomics, Livingston New Jersey, USA.
Reprod Biomed Online. 2020 Apr;40(4):479-493. doi: 10.1016/j.rbmo.2019.12.008. Epub 2019 Dec 19.
What are the incidence and patterns of meiotic trisomies and recombination separately and in relation to each other at the blastocyst stage via single nucleotide polymorphism genotyping combined with array comparative genomic hybridization.
Single nucleotide polymorphism microarrays were carried out on a total of 1442 blastocyst stage embryos derived from 268 fertile couples undergoing preimplantation genetic diagnosis for the purposes of avoiding transmittance of known single gene disorders to their offspring; 24-chromosome aneuploidy screening via array comparative genomic hybridization was carried out in parallel.
One hundred per cent of meiotic trisomies identified in these embryos were of maternal origin and their incidence increased significantly with advancing maternal age (P < 0.0001). A total of 55.8% of meiotic trisomies were meiosis I-type and 44.2% were meiosis II-type. Certain chromosomes were affected more by meiosis I-type errors, whereas others experienced more meiosis II-type errors. A detailed recombination analysis was carried out for 11,476 chromosomes and 17,763 recombination events were recorded. The average number of recombination sites was 24.0 ± 0.3 for male meiosis and 41.2 ± 0.6 for female meiosis (autosomes only). Sex-specific differences were observed in the locations of recombination sites. Comparative analysis conducted between 190 euploid embryos and 69 embryos presenting maternal meiotic trisomies showed similar recombination rates (P = 0.425) and non-recombinant chromatid rates (P = 0.435) between the two categories; differences, however, were observed when analysing embryos affected with specific maternal meiotic trisomies.
This study yielded unique data concerning recombination and the origin of aneuploidies observed during the first few days of life and provides a novel insight into these important biological processes.
通过单核苷酸多态性基因分型结合阵列比较基因组杂交技术，在囊胚阶段，分别和相互关联地研究减数分裂三体和重组的发生率和模式。
对 268 对进行胚胎植入前遗传学诊断以避免将已知的单基因疾病遗传给后代的生育能力正常的夫妇的 1442 个囊胚期胚胎进行了单核苷酸多态性微阵列分析；同时平行进行了 24 条染色体非整倍体的阵列比较基因组杂交筛查。
这些胚胎中 100%的减数分裂三体都是母源性的，其发生率随着母亲年龄的增长而显著增加（P < 0.0001）。总共 55.8%的减数分裂三体是减数分裂 I 型，44.2%是减数分裂 II 型。某些染色体受减数分裂 I 型错误的影响更大，而其他染色体则受减数分裂 II 型错误的影响更大。对 11476 条染色体和 17763 个重组事件进行了详细的重组分析。男性减数分裂的平均重组位点数为 24.0 ± 0.3，女性减数分裂的平均重组位点数为 41.2 ± 0.6（仅常染色体）。在重组位点的位置上观察到了性别特异性差异。将 190 个整倍体胚胎和 69 个存在母源减数分裂三体的胚胎进行比较分析，发现这两类胚胎的重组率（P = 0.425）和非重组染色单体率（P = 0.435）相似；然而，在分析受特定母源减数分裂三体影响的胚胎时，观察到了差异。
这项研究提供了关于在生命的头几天观察到的重组和非整倍体的起源的独特数据，并为这些重要的生物学过程提供了新的见解。
