Division of Molecular Embryonic Development, State Key Laboratory of Reproductive Biology, Institute of Zoology/Chinese Academy of Sciences, Beijing 100101, PR China.
Mol Aspects Med. 2013 Oct;34(5):919-38. doi: 10.1016/j.mam.2013.01.003. Epub 2013 Jan 23.
Prior to activation of the embryonic genome, the initiating events of mammalian development are under maternal control and include fertilization, the block to polyspermy and processing sperm DNA. Following gamete union, the transcriptionally inert sperm DNA is repackaged into the male pronucleus which fuses with the female pronucleus to form a 1-cell zygote. Embryonic transcription begins during the maternal to zygotic transfer of control in directing development. This transition occurs at species-specific times after one or several rounds of blastomere cleavage and is essential for normal development. However, even after activation of the embryonic genome, successful development relies on stored maternal components without which embryos fail to progress beyond initial cell divisions. Better understanding of the molecular basis of maternal to zygotic transition including fertilization, the activation of the embryonic genome and cleavage-stage development will provide insight into early human development that should translate into clinical applications for regenerative medicine and assisted reproductive technologies.
在胚胎基因组激活之前，哺乳动物发育的起始事件受母体控制，包括受精、多精受精的阻断和精子 DNA 的处理。配子结合后，转录惰性的精子 DNA 被重新包装到雄性原核中，雄性原核与雌性原核融合形成一个 1 细胞受精卵。胚胎转录在母体到合子控制的转移过程中开始指导发育。这种转变发生在物种特有的时间后，经过一轮或多轮卵裂球分裂，对正常发育是必不可少的。然而，即使在胚胎基因组被激活之后，成功的发育也依赖于储存的母体成分，没有这些成分，胚胎就无法在初始细胞分裂之外进一步发展。更好地理解母体到合子过渡的分子基础，包括受精、胚胎基因组的激活和卵裂期发育，将为早期人类发育提供深入的了解，这应该转化为再生医学和辅助生殖技术的临床应用。
