Pittsburgh Development Center, Division of Developmental & Regenerative Medicine, and Obstetrics-Gynecology-Reproductive Sciences, Cell Biology, and Bioengineering, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 204 Craft Avenue Pittsburgh, Pennsylvania, 15213, USA.
Division of Cardiometabolic Health, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, 97006, USA.
Sci Rep. 2019 Oct 25;9(1):15282. doi: 10.1038/s41598-019-51815-4.
With nearly ten million babies conceived globally, using assisted reproductive technologies, fundamental questions remain; e.g., How do the sperm and egg DNA unite? Does ICSI have consequences that IVF does not? Here, pronuclear and mitotic events in nonhuman primate zygotes leading to the establishment of polarity are investigated by multidimensional time-lapse video microscopy and immunocytochemistry. Multiplane videos after ICSI show atypical sperm head displacement beneath the oocyte cortex and eccentric para-tangential pronuclear alignment compared to IVF zygotes. Neither fertilization procedure generates incorporation cones. At first interphase, apposed pronuclei align obliquely to the animal-vegetal axis after ICSI, with asymmetric furrows assembling from the male pronucleus. Furrows form within 30° of the animal pole, but typically, not through the ICSI injection site. Membrane flow drives polar bodies and the ICSI site into the furrow. Mitotic spindle imaging suggests para-tangential pronuclear orientation, which initiates random spindle axes and minimal spindle:cortex interactions. Parthenogenetic pronuclei drift centripetally and assemble astral spindles lacking cortical interactions, leading to random furrows through the animal pole. Conversely, androgenotes display cortex-only pronuclear interactions mimicking ICSI. First cleavage axis determination in primates involves dynamic cortex-microtubule interactions among male pronuclei, centrosomal microtubules, and the animal pole, but not the ICSI site.
全球约有一千万例婴儿通过辅助生殖技术孕育，目前仍存在许多基本问题亟待解决，例如，精子和卵子的 DNA 是如何结合的？ICSI 是否会带来 IVF 所没有的后果？本研究通过多维延时视频显微镜和免疫细胞化学技术，研究了导致非人类灵长类动物胚胎极性建立的原核和有丝分裂事件。与 IVF 胚胎相比，ICSI 后的多层面视频显示，精子头部在卵母细胞皮层下的异常位移和偏心的Para-切线原核排列。两种受精程序均未产生整合锥。第一次间期，ICSI 后，原核呈斜向动物-植物轴排列，雄性原核从不对称的核沟开始组装。核沟在动物极形成 30°以内，但通常不会穿过 ICSI 注射点。膜流驱动极体和 ICSI 点进入核沟。有丝分裂纺锤体成像表明原核呈 Para-切线取向，这会引发随机的纺锤体轴和最小的纺锤体-皮层相互作用。孤雌原核向心漂移，并组装缺乏皮层相互作用的星状纺锤体，导致随机的核沟穿过动物极。相反，雄原核表现出类似于 ICSI 的皮层原核相互作用。灵长类动物的第一次卵裂轴决定涉及雄性原核、中心体微管和动物极之间的动态皮层-微管相互作用，但不涉及 ICSI 点。
