Wang Li, Wang Xiaohong, Zhang Jianguang, Song Zhuo, Wang Shufang, Gao Yang, Wang Jun, Luo Yaning, Niu Ziru, Yue Xiaojing, Xu Genming, Cram David S, Yao Yuanqing
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing, China.
Biol Reprod. 2014 May 8;90(5):95. doi: 10.1095/biolreprod.113.116459. Print 2014 May.
Embryos produced by assisted reproductive technologies are commonly associated with a high level of aneuploidy. Currently, 24-chromosome profiling of embryo biopsy samples by array-based methods is available to identify euploid embryos for transfer that have a higher potential for implantation and development to term. From a laboratory and patient perspective, there is a need to explore the feasibility of developing an alternative method for routine aneuploidy assessment of embryos that would be more comprehensive, cost-effective, and efficient. We speculated that aneuploidy could be readily assessed in test single-cell biopsy samples by first performing whole genome amplification followed by library generation, massively parallel shot-gun sequencing, and finally bioinformatics analysis to quantitatively compare the ratio of uniquely mapped reads to reference cells. Using Down syndrome as an example, the copy number change for chromosome 21 was consistently 1.5-fold higher in multiple cell and single-cell samples with a 47,XX,+21 karyotype. Applying the validated sequencing strategy to 10 sister blastomeres from a single human embryo, we showed that the aneuploidy status called by sequencing was consistent with short tandem repeat allelic profiling. These validation studies indicate that aneuploidy detection using sequencing-based methodology is feasible for further improving the practice of preimplantation genetic diagnosis.
辅助生殖技术产生的胚胎通常与高水平的非整倍体相关。目前，可通过基于阵列的方法对胚胎活检样本进行24条染色体分析，以识别具有更高着床和发育至足月潜力的整倍体胚胎用于移植。从实验室和患者的角度来看，有必要探索开发一种替代方法用于胚胎常规非整倍体评估的可行性，该方法应更全面、更具成本效益且更高效。我们推测，通过首先进行全基因组扩增，然后进行文库构建、大规模平行鸟枪法测序，最后进行生物信息学分析以定量比较唯一比对读数与参考细胞的比率，可在测试单细胞活检样本中轻松评估非整倍体。以唐氏综合征为例，在具有47,XX,+21核型的多个细胞和单细胞样本中，21号染色体的拷贝数变化始终高出1.5倍。将经过验证的测序策略应用于来自单个人类胚胎的10个姐妹卵裂球，我们发现测序所确定的非整倍体状态与短串联重复序列等位基因分析一致。这些验证研究表明，使用基于测序的方法检测非整倍体对于进一步改进植入前基因诊断的实践是可行的。
