de Smedt V, Crozet N, Gall L
I.N.R.A., Unité de Biologie de la Fécondation, Station de Physiologie Animale, Jouy-en-Josas, France.
J Exp Zool. 1994 Jun 1;269(2):128-39. doi: 10.1002/jez.1402690206.
In order to determine at which follicular size goat oocytes were capable of resuming and completing meiosis, we evaluated their ability to mature in vitro and measured their maturation promoting factor (MPF) activity by histone H1 kinase assay. The results indicated that goat oocyte meiotic competence developed progressively in follicles ranging from 0.5 to 3 mm; the oocytes acquired the ability to resume meiosis in follicles of 0.5-0.8 mm, to reach metaphase I (MI) in follicles of 1-1.8 mm, and to reach metaphase II (MII) in follicles larger than 3 mm. The presence of MPF activity was first observed in oocytes arrested at early prometaphase I and reached a maximum level in oocytes blocked in metaphase I (MI). In the second part of this study, RNA synthesis and nucleolar changes were analyzed during the growth period. The acquisition of meiotic competence was accompanied by nucleolar compaction and a dramatic decrease in RNA synthesis. Changes in protein patterns were also analyzed, but only slight differences were observed among oocytes from the different classes.
为了确定山羊卵母细胞在何种卵泡大小下能够恢复并完成减数分裂，我们评估了它们的体外成熟能力，并通过组蛋白H1激酶测定法测量了它们的成熟促进因子（MPF）活性。结果表明，山羊卵母细胞的减数分裂能力在直径0.5至3毫米的卵泡中逐步发展；卵母细胞在直径0.5 - 0.8毫米的卵泡中获得恢复减数分裂的能力，在直径1 - 1.8毫米的卵泡中达到减数第一次分裂中期（MI），并在直径大于3毫米的卵泡中达到减数第二次分裂中期（MII）。MPF活性首先在停滞于减数第一次分裂前期早期的卵母细胞中被观察到，并在停滞于减数第一次分裂中期（MI）的卵母细胞中达到最高水平。在本研究的第二部分，分析了生长期的RNA合成和核仁变化。减数分裂能力的获得伴随着核仁致密化和RNA合成的显著减少。还分析了蛋白质模式的变化，但在不同类别的卵母细胞之间仅观察到细微差异。
