Collas P, Poccia D L
Department of Food Science, Agricultural University of Norway, Aas, Norway.
Mol Reprod Dev. 1995 Sep;42(1):106-13. doi: 10.1002/mrd.1080420114.
We demonstrate that complete sea urchin male pronuclear development in vitro is a two-step process involving membrane-independent chromatin decondensation and nuclear envelope-dependent pronuclear swelling. In the absence of cytoplasmic membrane vesicles (MVs), permeabilized sperm chromatin decondenses into a spherical nucleus of approximately 4 microns in diameter. Pronuclear swelling to approximately 7 microns requires an intact nuclear envelope, and the degree of swelling is limited by the amount of MVs assembled on the chromatin. Furthermore, after a nuclear envelope is formed, swelling can occur in the absence of additional cytoplasmic MVs. Nuclear swelling also requires ATP hydrolysis, Ca2+ and cytosolic factors, some of which are sensitive to heat and to the sulfhydryl alkylating agent, N-ethylmaleimide. The requirement for a nuclear envelope and the rate of pronuclear swelling are consistent with previous in vivo observations.
我们证明，海胆雄原核在体外的完全发育是一个两步过程，包括不依赖膜的染色质解聚和依赖核膜的原核肿胀。在没有细胞质膜泡（MVs）的情况下，通透的精子染色质解聚成直径约4微米的球形细胞核。原核肿胀到约7微米需要完整的核膜，并且肿胀程度受组装在染色质上的MVs数量限制。此外，在形成核膜后，即使没有额外的细胞质MVs也会发生肿胀。核肿胀还需要ATP水解、Ca2+和胞质因子，其中一些对热和巯基烷基化剂N-乙基马来酰亚胺敏感。对核膜的需求和原核肿胀速率与先前的体内观察结果一致。
