Mitochondrial distribution and adenosine triphosphate content of bovine oocytes before and after in vitro maturation:: Correlation with morphological criteria and developmental capacity after in vitro fertilization and culture
Mitochondrial distribution and adenosine triphosphate content of bovine oocytes before and after in vitro maturation:: Correlation with morphological criteria and developmental capacity after in vitro fertilization and culture
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DOI：
10.1095/biolreprod64.3.904
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发表时间：
2001-03-01
影响因子：
3.6
通讯作者：
Wolf, E
中科院分区：
文献类型：
--
作者：
Stojkovic, M;Machado, SA;Wolf, E
本研究测定了牛卵母细胞体外成熟前后线粒体的分布和ATP含量。卵丘-卵母细胞复合体根据形态学标准进行分类：第1类，同质的卵母细胞细胞质，致密的多层卵丘;第2类，细胞质具有小的不均匀区域，致密的卵丘超过五层;第3类，异质/空泡化细胞质，三到五层卵丘，包括小区域的裸露透明带;第4类，异质细胞质，完全或大部分裸露。在未成熟的卵母细胞中，MitoTracker绿色染色显示细胞质周围的线粒体团块，在1类卵母细胞中具有强的均匀信号，在2类卵母细胞中染色较弱，在3类卵母细胞中线粒体分布在空泡周围，在4类卵母细胞中线粒体染色较差。IVM后，线粒体团更多地向中心分配，变得更大，染色更密集的第1类和第2类卵母细胞。这也是真实的3类卵母细胞，然而，线粒体保持其泡周分布。4类卵母细胞未见线粒体重组。IVM前，第1类卵母细胞ATP含量（1.8pmol）高于第2类卵母细胞（1.6pmol），且显著高于第3类卵母细胞（1.4pmol）和第4类卵母细胞（0.9pmol）（P < 0.01）。IVM使各类卵母细胞的ATP含量显著增加（P < 0.01），而排出极体的卵母细胞与未排出极体的卵母细胞之间无差异。体外受精（IVF）后168 h，第1类和第2类卵母细胞发育至桑椹胚或囊胚期的数量显著多于第3类和第4类卵母细胞（P < 0.05）。来自1类和2类卵母细胞的扩张囊胚细胞总数显著高于来自3类和4类卵母细胞的扩张囊胚细胞总数（P < 0.05）。这些数据表明，线粒体重组和ATP水平是不同的形态良好和贫穷的卵母细胞，可能是负责体外受精后的不同发育能力。
In this study we evaluated mitochondrial distribution and ATP content of individual bovine oocytes before and after in vitro maturation (IVM). Cumulus-oocyte complexes were classified according to morphological criteria: category 1, homogeneous oocyte cytoplasm, compact multilayered cumulus oophorus; category 2, cytoplasm with small inhomogeneous areas, more than five layers of compact cumulus; category 3, heterogeneous/vacuolated cytoplasm, three to five layers of cumulus including small areas of denuded zona pellucida; category 4, heterogeneous cytoplasm, completely or in great part denuded. In immature oocytes, staining with MitoTracker green revealed mitochondrial clumps in the periphery of the cytoplasm, with a strong homogenous signal in category 1 oocytes, a weaker staining in category 2 oocytes,allocation of mitochondria around vacuoles in category 3 oocytes, and poor staining of mitochondria in category 4 oocytes. After IVM, mitochondrial clumps were allocated more toward the center, became larger, and stained more intensive in category land 2 oocytes. This was also true for category 3 oocytes; however, mitochondria maintained their perivacuolar distribution. No mitochondrial reorganization was seen for category 4 oocytes. Before IVM, the average ATP content of category 1 oocytes (1.8 pmol) tended to be higher than that of category 2 oocytes (1.6 pmol) and was significantly (P < 0.01) higher than in category 3 (1.4 pmol) and 4 oocytes (0.9 pmol). The IVM resulted in a significant (P < 0.01) increase in the average ATP content of all oocyte categories, with no difference between oocytes extruding versus non-extruding a polar body. After in vitro fertilization (IVF) and culture, significantly (P < 0.05) more category 1 and 2 than category 3 and 4 oocytes developed to the morula or blastocyst stage (determined 168 h after IVF). Total cell numbers of expanded blastocysts derived from category 1 and 2 oocytes were significantly (P < 0.05) higher than of those originating from category 3 and 4 oocytes. These data indicate that mitochondrial reorganization and ATP levels are different between morphologically good and poor oocytes and may be responsible for their different developmental capacity after IVF.