the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote
例句
The male and female pronucleus fused finally.Most hybrids could develop normally. 成熟的雌雄原核形成后完成融合过程，形成合子核，受精过程结束。
Objective To investigate the relationship between the first polar body morphology of oocyte and the zygote morphology in pronucleus stage, embryo quality in cleavage stage. 目的探讨卵细胞第一极体形态与原核期受精卵形态、卵裂期胚胎质量的关系。
Treated at anaphase of second meiosis, two female pronuclei and one male pronucleus of the fertilized eggs became abnormal during their fusion and separation procedure. 受精卵在第2次减数分裂的后期时接受处理，可使部分受精卵的两个雌性原核和一个雄性原核在融合和分离过程中发生异常。
