Zhang Shuo-Ping, Lu Chang-Fu, Gong Fei, Xie Ping-Yuan, Hu Liang, Zhang Shun-Ji, Lu Guang-Xiu, Lin Ge
Institute of Reproductive and Stem Cell Engineering, Central South University, Xiangya Road 88#, 410078, Changsha, People's Republic of China.
Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China.
J Assist Reprod Genet. 2017 May;34(5):563-571. doi: 10.1007/s10815-017-0881-y. Epub 2017 Feb 11.
We aimed to determine the developmental potential of human reconstructed oocytes after polar body genome transfer (PBT) and to report the case of a woman with multiple cycles of severe embryo fragmentation.
Fresh and cryopreserved first polar bodies (PB1s) were transferred to enucleated metaphase II oocytes (PB1T), while fresh PB2s were removed from fertilized oocytes and used instead of the female pronucleus in donor zygotes. Reconstructed oocytes underwent intracytoplasmic sperm injection (ICSI) and were cultured to blastocyst. Biopsied trophectoderm cells of PBT-derived blastocysts were screened for chromosomes by next-generation sequencing (NGS). Then, cryopreserved PB1T was carried out in one woman with a history of several cycles of extensive embryo fragmentation, and the blastocysts derived from PB1T were screened for aneuploidy but not transferred to the patient.
There were no significant differences in the rates of normal fertilization and blastocyst formation between fresh and cryopreserved PB1T and control oocytes. Of the three fresh and three cryopreserved PB1T-derived blastocysts, two and one blastocysts exhibited normal diploidy respectively. In contrast, 17 PB2 transfers yielded 16 two pronuclei (2PN) zygotes with one normal and one small-sized pronucleus each and no blastocyst formation. In the female patient, 18 oocytes were inseminated by ICSI in the fourth cycle and the PB1s were biopsied. Although the embryos developed from the patient's own oocytes showed severe fragmentation, the oocytes reconstructed after PB1T produced three chromosomally normal blastocysts.
Normal blastocysts can develop from human reconstructed oocytes after PB1T. The application of the first PB transfers may be beneficial to patients with a history of poor embryo development and excessive fragmentation.
我们旨在确定极体基因组转移（PBT）后人类重构卵母细胞的发育潜能，并报告一名患有多周期严重胚胎碎片化的女性病例。
将新鲜和冷冻保存的第一极体（PB1）转移至去核的中期II卵母细胞（PB1T）中，而新鲜的PB2则从受精的卵母细胞中取出，并用于替代供体合子中的雌性原核。重构卵母细胞进行胞浆内单精子注射（ICSI）并培养至囊胚。通过下一代测序（NGS）对PBT来源囊胚的活检滋养外胚层细胞进行染色体筛查。然后，对一名有多次广泛胚胎碎片化周期病史的女性进行冷冻保存的PB1T，对PB1T来源的囊胚进行非整倍体筛查，但未移植给患者。
新鲜和冷冻保存的PB1T与对照卵母细胞在正常受精率和囊胚形成率方面无显著差异。在三个新鲜和三个冷冻保存的PB1T来源的囊胚中，分别有两个和一个囊胚表现出正常的二倍体。相比之下，17次PB2转移产生了16个双原核（2PN）合子，每个合子有一个正常原核和一个小原核，且无囊胚形成。在该女性患者中，第四个周期通过ICSI对18个卵母细胞进行授精并对PB1进行活检。尽管患者自身卵母细胞发育的胚胎显示出严重碎片化，但PB1T后重构的卵母细胞产生了三个染色体正常的囊胚。
PB1T后人类重构卵母细胞可发育出正常囊胚。首次PB转移的应用可能对有胚胎发育不良和过度碎片化病史的患者有益。
