Roelen Bernard A J
Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Uppsalalaan 8, 3584CT Utrecht, Netherlands. Email:
Reprod Fertil Dev. 2019 Jan;32(2):98-103. doi: 10.1071/RD19255.
Although millions of oocytes are formed during embryo and fetal development in the cow, only a small fraction of these will form a developmentally competent oocyte and be fertilised. Development to competence relies on an intimate contact between the oocyte and the surrounding somatic cells in ovarian follicles, via both direct cell-cell contact and paracrine signalling. An important aspect of oocyte maturation is the segregation of homologous chromosomes and subsequently sister chromatids to form a haploid oocyte. Furthermore, the cytoplasm needs to be prepared for the formation of pronuclei and nuclear reprogramming to form a totipotent zygote. Conditions such as high levels of fatty acids or oxidative stress constrain the developmental competence of oocytes, and a better insight into these processes may help improve in vitro and in vivo oocyte maturation success. In addition, identification of the developmentally competent oocyte is useful for the efficiency of (artificial) reproduction.
虽然母牛在胚胎和胎儿发育期间会形成数百万个卵母细胞，但其中只有一小部分会发育成为具有发育能力的卵母细胞并受精。发育至具备能力依赖于卵母细胞与卵巢卵泡中周围体细胞之间通过直接细胞间接触和旁分泌信号传导的密切接触。卵母细胞成熟的一个重要方面是同源染色体的分离，随后姐妹染色单体分离以形成单倍体卵母细胞。此外，细胞质需要为原核的形成和核重编程做好准备，以形成全能合子。诸如高脂肪酸水平或氧化应激等条件会限制卵母细胞的发育能力，对这些过程的更好理解可能有助于提高体外和体内卵母细胞成熟的成功率。此外，识别具有发育能力的卵母细胞对于（人工）繁殖效率很有用。
