Effect of 17β-estradiol on the in vitro maturation of bovine oocytes
Effect of 17β-estradiol on the in vitro maturation of bovine oocytes
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DOI：
10.1016/s0093-691x(02)01082-8
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发表时间：
2002-12-01
期刊：
影响因子：
2.8
通讯作者：
Bevers, MM
中科院分区：
文献类型：
--
作者：
Beker, ARCL;Colenbrander, B;Bevers, MM
尽管1杯/毫升的17 -雌二醇（E2）常用于常规体外成熟（IVM）和体外受精（IVF），但其效果仍存在争议。我们的研究目的是研究E2对牛卵母细胞体外受精和随后胚胎发育的影响，使用一种确定的培养基。牛卵丘细胞复合物（COCs）从屠宰场卵巢的2 ~ 8mm卵泡中抽取，在1马克杯/毫升E2（含或不含0.05 IU/ml重组hFSH）存在的TCM199中成熟。不含E2、FSH或两者的培养作为对照。COCs在含5% CO2的潮湿空气中，在39℃下成熟22℃。为了研究E2加FSH和不加FSH对核成熟的影响，成熟后固定COCs， DAPI染色评估核分期。同样，在E2存在下，脱去的卵母细胞（DO）成熟，22it后评估核期。为了研究IVM过程中E2加和不加FSH对随后胚胎发育的影响，将体外成熟的COCs在体外受精，去除卵丘细胞后，将推定的受精卵在BRL单层上共培养11天。第4天和第9天和第11天分别测定卵裂胚数和囊胚数。在TCM199中添加1 mug/ml E2显著降低了中期II （MII）的比例（分别为56.3%和74.0%），增加了核畸变的比例（分别为13.3%和2.1%）。当DO成熟时，E2对核成熟的负面影响更强；E2组和对照组分别有25.1%和60.0%的卵母细胞达到MII期。当COCs在添加FSH的TCM 199中成熟时，添加1马克杯/毫升E2并不影响MR卵母细胞的比例，尽管与对照组相比，观察到核畸变率更高。IVM期间E2的存在也降低了囊胚率（对照组和E2组分别为14.4%和10.0%）。然而，当FSH存在时，添加E2对卵裂率和囊胚形成没有影响（对照组和E2组分别为20.3%和21.7%）。
Although 1 mug/ml of 17beta-estradiol (E2) is often used in routine in vitro maturation (IVM) and in vitro fertilization (IVF), its effect remains controversial. The objective of our study was to investigate the effects of E2 on bovine oocyte IVM and subsequent embryo development, using a defined medium. Bovine cumulus oocyte complexes (COCs), aspirated from 2 to 8 mm follicles of slaughterhouse ovaries, were matured in TCM199 in the presence of 1 mug/ml E2 with or without 0.05 IU/ml recombinant hFSH. Cultures without E2, FSH or both served as controls. COCs were matured for 22 It at 39 degreesC in a humidified atmosphere of 5% CO2 in air. To investigate the effect of E2 with and without FSH on nuclear maturation, COCs were fixed after maturation and the nuclear stage was assessed following DAPI staining. Similarly, denuded oocytes (DO) were matured in the presence of E2 and the nuclear stage assessed after 22 It. To investigate the effect of E2 with and without FSH during IVM on subsequent embryo development, in vitro matured COCs were fertilized in vitro and after removal of the cumulus cells, the presumed zygotes were cocultured on BRL monolayer for 11 days. At Day 4, the number of cleaved embryos, and at Days 9 and 11, the number of blastocysts, were assessed.Addition of 1 mug/ml E2 to TCM199 significantly decreased the percentage of Metaphase II (MII) compared to control (56.3 and 74.0%, respectively), and increased the percentage of nuclear aberrations compared to control (13.3 and 2.1%, respectively). The negative effect of E2 on nuclear maturation was stronger when DO were matured; 25.1 and 60.0% of the oocytes reached MII stage for the E2 and control groups, respectively. When COCs were matured in TCM 199 supplemented with FSH, the addition of 1 mug/ml E2 did not influence the proportion of MR oocytes, although a higher percentage of nuclear aberrations as compared to control was observed. Presence of E2 during IVM also decreased the blastocyst rate (14.4 and 10.0% for control and E2 groups, respectively). However, when FSH was present, the addition of E2 had no effect on the cleavage rate and blastocyst formation (20.3 and 21.7% for control and E2 groups, respectively).