Chankitisakul Vibuntita, Tharasanit Theerawat, Tasripoo Kriengsak, Techakumphu Mongkol
Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
Vet Med Int. 2010 Dec 22;2010:382989. doi: 10.4061/2010/382989.
This paper aimed to study the dynamics of early embryonic development, in terms of redistribution of cytoskeleton (microtubules, actin microfilaments) and chromatin configurations during the first cell cycle in swamp buffalo embryos. Oocytes were matured and fertilized in vitro, and they were fixed at various time points after IVF. At 6 h after IVF, 44.4% matured oocytes were penetrated by spermatozoa. Partial ZP digestion, however, did not improve fertilization rate compared to control (P > .05). At 12 h after IVF, the fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the paternal chromatin continued to decondense. A sperm aster was observed radiating from the base of the decondensing sperm head. At 18 h after IVF, most presumptive zygotes had reached the pronuclear stage. The sperm aster was concurrently enlarged to assist the migration and apposition of pronuclei. Cell cleavage was facilitated by microfilaments and firstly observed by 30 h after IVF. In conclusion, the cytoskeleton actively involves with the process of fertilization and cleavage in swamp buffalo oocytes. The centrosomal material is paternally inherited. Fertilization failure is predominantly caused by poor sperm penetration. However, partial digestion of ZP did not improve fertilization rate.
本文旨在研究沼泽水牛胚胎第一个细胞周期中细胞骨架（微管、肌动蛋白微丝）重新分布和染色质构型方面的早期胚胎发育动力学。卵母细胞在体外成熟并受精，在体外受精后的不同时间点进行固定。体外受精后6小时，44.4%的成熟卵母细胞被精子穿透。然而，与对照组相比，部分透明带消化并未提高受精率（P>.05）。体外受精后12小时，受精卵进入第二次减数分裂，形成雌原核，同时父本染色质继续解聚。观察到一个精子星体从解聚的精子头部基部发出。体外受精后18小时，大多数推测的合子达到原核阶段。精子星体同时扩大，以协助原核的迁移和并置。微丝促进细胞分裂，在体外受精后30小时首次观察到。总之，细胞骨架积极参与沼泽水牛卵母细胞的受精和分裂过程。中心体物质由父本遗传。受精失败主要是由精子穿透不良引起的。然而，透明带部分消化并未提高受精率。
