Yamashita M, Onozato H, Nakanishi T, Nagahama Y
Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki, Japan.
Dev Biol. 1990 Jan;137(1):155-60. doi: 10.1016/0012-1606(90)90016-c.
The gynogenetic fish, Carassius auratus langsdorfii (the ginbuna, a crucian carp), provides an interesting model for the study of the mechanisms controlling male pronucleus formation. When the sperm nucleus of a different subspecies (C. a. cuvieri) is incorporated into the gynogenetic egg, the nuclear envelope of the spermatozoon is not broken down, and the pronucleus fails to develop, although dispersion of the sperm chromatin occurs to some extent within the space limited by the nuclear envelope. When spermatozoa without plasma membranes and nuclear envelopes were microinjected into mature activated eggs, the sperm nuclei underwent chromatin dispersion, nuclear envelope formation, DNA synthesis, and transformation into male pronuclei. These results indicate that the failure of the male pronucleus to form in ginbuna is primarily due to the failure of sperm nuclear envelope breakdown. We conclude that sperm nuclear envelope breakdown is an indispensable step for the development of the male pronucleus.
雌核发育的鱼类——兰氏鲫（银鲫，一种鲫鱼），为研究控制雄原核形成的机制提供了一个有趣的模型。当不同亚种（库维氏鲫）的精子细胞核被注入雌核发育的卵中时，精子的核膜不会解体，原核也无法发育，尽管精子染色质在核膜限定的空间内会发生一定程度的分散。当将没有质膜和核膜的精子显微注射到成熟的激活卵中时，精子细胞核会经历染色质分散、核膜形成、DNA合成，并转化为雄原核。这些结果表明，银鲫中雄原核无法形成主要是由于精子核膜解体失败。我们得出结论，精子核膜解体是雄原核发育不可或缺的一步。
