Laverge H, De Sutter P, Verschraegen-Spae M R, De Paepe A, Dhont M
Infertility Centre, Department of Obstetrics and Gynaecology, University Hospital, Gent, Belgium.
Hum Reprod. 1997 Apr;12(4):809-14. doi: 10.1093/humrep/12.4.809.
The potential for implantation of human embryos obtained by in-vitro fertilization is presumably determined to a large extent by their chromosomal constitution but cytogenetic analysis of preimplantation embryos has been hampered by a number of practical and technical problems. With the advent of fluorescent in-situ hybridization (FISH) a practical method for numerical chromosomal analysis has become available. A limited amount of data has been obtained with FISH on human embryos using probes binding to chromosomes X, Y, 16, 18 and 13/21 combined or for chromosomes X and Y or 1 and 17. It was our purpose to extend these data by the combined analysis of chromosomes X, Y and 1 in spare human embryos. A short fluorescent in-situ hybridization procedure involving the simultaneous use of three deoxyribonucleic acid probes detected with red, green, and a mixture of red and green was used to determine chromosomal abnormalities in 116 spare embryos with a poor morphological score and/or displaying one or more multinucleated blastomeres. The majority of the embryos was obtained by intracytoplasmic sperm injection. Less than half of the embryos (n = 54) were diploid and only 39 of them were uniformly XY11 or XX11; two embryos showed a non-disjunction and 13 embryos were aneuploid. Of the remainder, 22 were mosaic, nine were either haploid, triploid or tetraploid and 12 embryos were classified as chaotic. The latter pattern was particularly frequent in multinucleated blastomeres. Our data are comparable with those obtained with FISH using other chromosomal probes and confirm that the majority of preimplantation embryos carry a numerical chromosomal defect. Aneuploidy for chromosome 1 does not appear to be more common in preimplantation embryos than is reported for other chromosomes. Although the high incidence of chromosomal anomalies is presumably biased by the fact that only embryos with a poor morphological score were analysed, it nevertheless indicates that natural selection is the foremost reason for the low implantation rates of human preimplantation embryos in in-vitro fertilization (IVF) programmes.
体外受精获得的人类胚胎的着床潜力大概在很大程度上由其染色体组成决定，但着床前胚胎的细胞遗传学分析一直受到一些实际和技术问题的阻碍。随着荧光原位杂交（FISH）技术的出现，一种用于染色体数目分析的实用方法已经可用。使用与X、Y、16、18和13/21号染色体结合的探针，或者针对X和Y染色体或1和17号染色体，通过FISH已经获得了关于人类胚胎的有限数据。我们的目的是通过对备用人类胚胎中的X、Y和1号染色体进行联合分析来扩展这些数据。采用一种简短的荧光原位杂交程序，同时使用三种分别用红色、绿色以及红色和绿色混合检测的脱氧核糖核酸探针，来确定116个形态评分较差和/或显示一个或多个多核卵裂球的备用胚胎中的染色体异常情况。大多数胚胎是通过胞浆内单精子注射获得的。不到一半的胚胎（n = 54）是二倍体，其中只有39个是均匀的XY11或XX11；两个胚胎显示有不分离现象，13个胚胎是非整倍体。其余的胚胎中，22个是嵌合体，9个是单倍体、三倍体或四倍体，12个胚胎被归类为混乱型。后一种模式在多核卵裂球中特别常见。我们的数据与使用其他染色体探针通过FISH获得的数据相当，并证实大多数着床前胚胎存在染色体数目缺陷。1号染色体的非整倍体在着床前胚胎中似乎并不比其他染色体报道的更常见。尽管染色体异常的高发生率可能因仅分析了形态评分较差的胚胎这一事实而有偏差，但它仍然表明自然选择是体外受精（IVF）程序中人类着床前胚胎着床率低的首要原因。
