Department of Biomedicine, Institute of Bio- and Translational Medicine, University of Tartu, Tartu, Estonia; Competence Center on Health Technologies, Tartu, Estonia; Department of Biotechnology, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
Laboratory of Molecular Diagnostics, Research Institute of Medical Genetics, Tomsk, National Research Medical Center of Russian Academy of Science, Tomsk, Russian Federation; Department of Cytology and Genetics, National Research Tomsk State University, Tomsk, Russian Federation.
Fertil Steril. 2018 Jun;109(6):1127-1134.e1. doi: 10.1016/j.fertnstert.2018.02.008.
To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst.
Prospective study.
Academic and in vitro fertilization units.
PATIENT(S): Sixteen donated cryopreserved embryos at blastocyst stage.
INTERVENTION(S): BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS).
MAIN OUTCOME MEASURE(S): Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments.
RESULT(S): Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM.
CONCLUSION(S): BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised.
比较源自同一囊胚的囊胚腔液（BF）、内细胞团（ICM）和滋养外胚层（TE）细胞的基因组谱。
前瞻性研究。
学术和体外受精单位。
16 个处于囊胚期的冷冻胚胎。
通过下一代测序（NGS）从每个囊胚中取出 BF、TE 和 ICM 细胞，以进行染色体分析。
BF、TE 和 ICM 样本的非整倍体筛查和嵌合体评估，随后比较三个囊胚腔室之间的基因组谱。
在 16 个囊胚中，有 10 个 BF 样本和 14 个 TE 和 ICM 样本提供了可靠的 NGS 数据，可用于全面的染色体分析。只有 40.0%的 BF-DNA 核型与 TE 或 ICM 完全一致，而 TE 与 ICM 的一致性为 85.7%。此外，BF-DNA 存在镶嵌性非整倍体，且 BF 中受影响的染色体总数明显高于 TE 和 ICM。
BF-DNA 可成功扩增并进行 NGS，但由于与 ICM 和 TE 的不匹配增加，BF 不能充分代表胚胎其余部分的状态。为了克服与 BF 取样和处理相关的生物学和技术挑战，囊胚活检需要改进实验室方案和非整倍体检测算法。因此，TE 活检仍然是预测胚胎核型的最有效方法，不建议将 BF 用作植入前遗传筛查的单一 DNA 来源。
