Wiesak Teresa, Wasielak Marta, Złotkowska Aleksandra, Milewski Robert
Department of Gamete and Embryo Biology, The Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland.
Department of Gamete and Embryo Biology, The Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland; Center of Gynaecology and Endocrinology and Reproductive Medicine - Artemida, Olsztyn, Poland.
Cryobiology. 2017 Jun;76:18-23. doi: 10.1016/j.cryobiol.2017.05.001. Epub 2017 May 6.
The purpose of our study was to assess the effect of vitrification with or without the presence of calcium in the vitrification solution on the: 1) diameter of oocytes and thickness of the zona pellucida, 2) zona pellucida hardening, 3) expression of mRNA follistatin (FST) and cathepsin B (CTSB) in oocytes and 4) developmental competence of embryos derived from in vitro matured and vitrified oocytes. The results of our study demonstrate, that vitrification did not alter thickness of the zona pellucida and diameter of the oocytes, however it triggered hardening of the zona pellucida. The presence of calcium in the vitrification solutions intensified hardening of zona in immature and mature oocytes (P < 0.04, P < 0.001, respectively) and provoked increased mRNA FST expression in oocytes matured in vitro compared to immature oocytes (P < 0.01) and those vitrified without calcium (P < 0.004). CTSB mRNA expression was increased in immature oocytes and oocytes vitrified with calcium compare to mature oocytes (P < 0.02). The developmental potential of vitrified oocytes was impaired compared to non-vitrified oocytes, being more evident in oocytes vitrified with calcium. In summary, vitrification did not change the oocyte diameter and thickness of the zona pellucida and expression of FST and CTSB mRNA. It diminished developmental potential of the vitrified oocytes. The presence of calcium in the vitrification solutions increased hardening of zona pellucida as well as affected the level of FST and CTSB mRNA in oocytes and developmental potential of these oocytes.
1）卵母细胞直径和透明带厚度；2）透明带硬化；3）卵母细胞中卵泡抑素（FST）和组织蛋白酶B（CTSB）mRNA的表达；4）体外成熟并经玻璃化处理的卵母细胞所衍生胚胎的发育能力。我们的研究结果表明，玻璃化处理并未改变透明带厚度和卵母细胞直径，但会引发透明带硬化。玻璃化溶液中钙的存在加剧了未成熟和成熟卵母细胞透明带的硬化（分别为P < 0.04，P < 0.001），并且与未成熟卵母细胞相比，体外成熟卵母细胞中mRNA FST的表达增加（P < 0.01），与无钙玻璃化处理的卵母细胞相比也增加（P < 0.004）。与成熟卵母细胞相比，未成熟卵母细胞和添加钙玻璃化处理的卵母细胞中CTSB mRNA表达增加（P < 0.02）。与未玻璃化处理的卵母细胞相比，玻璃化处理的卵母细胞发育潜能受损，在添加钙玻璃化处理的卵母细胞中更为明显。总之，玻璃化处理未改变卵母细胞直径、透明带厚度以及FST和CTSB mRNA的表达。它降低了玻璃化处理卵母细胞的发育潜能。玻璃化溶液中钙的存在增加了透明带的硬化，同时影响了卵母细胞中FST和CTSB mRNA的水平以及这些卵母细胞的发育潜能。
