Charbonneau M
Laboratoire de Biologie et Génétique du Développement, Université de Rennes I, France.
Cell Differ Dev. 1990 Jun;30(3):171-9. doi: 10.1016/0922-3371(90)90137-l.
The cortical endoplasmic reticulum (CER), which develops and becomes organized during oocyte maturation in Xenopus laevis (anuran amphibians), has been thought to be essential for the propagation of the activating signal at the time of fertilization, possibly by regulating intracellular Ca2+ (Ca2+i) (Charbonneau and Grey, Dev. Biol. 102, 90-97, 1984). The present paper demonstrates that changing intracellular pH (pHi) has an influence on the structure and organization of the CER in unactivated Xenopus eggs. Acidifying the egg cytoplasm from its normal value, pH 7.5, to about 6.8, with CO2, produced a dramatic increase in the proportion of the CER being in the form of a continuous and well-developed network. On the other hand, alkalinizing the egg cytoplasm from 7.5 to about 8.2, with NH4Cl, induced a general disruption and vesicularization of the CER. These effects of pHi on a Cai2(+)-regulating system are discussed, taking into account possible artefacts generated during fixation.
非洲爪蟾（无尾两栖动物）卵母细胞成熟过程中发育并形成组织的皮质内质网（CER），被认为在受精时激活信号的传播中至关重要，可能是通过调节细胞内钙离子（Ca2+i）来实现的（Charbonneau和Grey，《发育生物学》102卷，90 - 97页，1984年）。本文证明，改变细胞内pH值（pHi）会影响未激活的非洲爪蟾卵中CER的结构和组织。用二氧化碳将卵细胞质从其正常值pH 7.5酸化至约6.8，会使呈连续且发育良好网络形式的CER比例显著增加。另一方面，用氯化铵将卵细胞质从7.5碱化至约8.2，会导致CER普遍破坏并形成囊泡。考虑到固定过程中可能产生的假象，讨论了pHi对Ca2+i调节系统的这些影响。
