Evsikov S, Verlinsky Y
Reproductive Genetics Institute, Chicago, IL 60657, USA.
Hum Reprod. 1998 Nov;13(11):3151-5. doi: 10.1093/humrep/13.11.3151.
Although mosaicism was shown to be a normal feature in cleaving embryos, its consequences for the late preimplantation stages are unknown. We performed blastocyst immunosurgery, followed by fluorescent in-situ hybridization (FISH), to determine the number of cells and degree of mosaicism in the inner cell mass (ICM) of human blastocysts. Of 47 ICM samples analysed, 20 had aneuploid cells, and two also had a few tetraploid cells. The average degree of aneuploidy in the ICM was similar to the overall blastocyst mosaicism, suggesting that there is probably no selection for euploid ICM. The lower degree of blastocyst mosaicism, compared with the cleavage-stage embryos, may be due to a mechanism of selection against the embryos with high frequency of mosaicism, leading to elimination of these embryos prior to blastocyst formation.
虽然镶嵌现象被证明是正在分裂的胚胎的一种正常特征，但其对植入前晚期阶段的影响尚不清楚。我们进行了囊胚免疫手术，随后进行荧光原位杂交（FISH），以确定人类囊胚内细胞团（ICM）中的细胞数量和镶嵌程度。在分析的47个ICM样本中，20个有非整倍体细胞，2个还有一些四倍体细胞。ICM中的非整倍体平均程度与囊胚整体镶嵌现象相似，这表明可能不存在对整倍体ICM的选择。与卵裂期胚胎相比，囊胚镶嵌现象程度较低，可能是由于对镶嵌频率高的胚胎存在一种选择机制，导致这些胚胎在囊胚形成之前就被淘汰。
