The chromosomal constitution of embryos arising from monopronuclear oocytes in programmes of assisted reproduction.
The chromosomal constitution of embryos arising from monopronuclear oocytes in programmes of assisted reproduction.
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DOI：
10.1155/2014/418198
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发表时间：
2014
影响因子：
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通讯作者：
Rosenbusch B
中科院分区：
文献类型：
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作者：
Rosenbusch B
在辅助生殖过程中，对卵母细胞仅显示一个原核的评估具有不确定性。对不同发育阶段遗传构成的数据汇编表明，受影响的卵母细胞能够发育成单倍体、二倍体和具有或多或少复杂染色体组成的马赛克胚胎。在大多数情况下（约80%），单倍体似乎是由雌性生殖引起的，而孤雌生殖或雄性生殖则不太常见。大多数二倍体胚胎是由受精事件导致的，包括两个原核的异步形成或原核融合在非常早期的阶段。如果一个原核未能发育，而另一个原核已经含有二倍体基因组，或者单倍体基因组进行内重复，有时会发生单亲本二倍体。一般来说，常规体外受精获得双亲本二倍体胚胎的机会似乎高于卵胞浆内单精子注射。如果设想从单核卵母细胞获得的胚胎移植，应尝试将其培养到囊胚，因为大多数单倍体胚胎无法达到这一阶段。建议在移植前对患者进行全面的潜在风险咨询，如果可以的话，可以提供植入前遗传学诊断。
The assessment of oocytes showing only one pronucleus during assisted reproduction is associated with uncertainty. A compilation of data on the genetic constitution of different developmental stages shows that affected oocytes are able to develop into haploid, diploid, and mosaic embryos with more or less complex chromosomal compositions. In the majority of cases (~80%), haploidy appears to be caused by gynogenesis, whereas parthenogenesis or androgenesis is less common. Most of the diploid embryos result from a fertilization event involving asynchronous formation of the two pronuclei or pronuclear fusion at a very early stage. Uniparental diploidy may sometimes occur if one pronucleus fails to develop and the other pronucleus already contains a diploid genome or alternatively a haploid genome undergoes endoreduplication. In general, the chance of obtaining a biparental diploid embryo appears higher after conventional in vitro fertilization than after intracytoplasmic sperm injection. If a transfer of embryos obtained from monopronuclear oocytes is envisaged, it should be tried to culture them up to the blastocyst since most haploid embryos are not able to reach this stage. Comprehensive counselling of patients on potential risks is advisable before transfer and a preimplantation genetic diagnosis could be offered if available.