大波斯菊小孢子发生时期线粒体的动态

运用电镜及电镜细胞化学等方法对大波斯菊小孢子发生时期,即小孢子母细胞到四分休的整个发育过程中的线粒体动态进行了观察。实验表明:在小孢子母细胞减数分裂过程中,线粒体要经受一个复杂的反分化过程。在减数分裂前期的早期阶段,线粒体的数量增加很快;与此同时,一些空白的被称作”spherical inclusion”的细胞器(STs)也随之产生,它们代表着新产生细胞器的退化。造成退化的原因可能是由于细胞器缺少核密码的调控。推测减数分裂后线粒体围核现象可能与ATP、信息大分子及其他物质的传递有关。

Mitochondria Behaviour During Microsporogenesis in

Using a combination of E.M. electron microscopic cytochemistry and experiments with inhibitors (N, DNP, Actinomycin D), mitochondria behaviour during microsporogenesis in Cosmos bipinnatus was examined. In male cells, mitochondrial populations underwent comprehensive dedifferentiation, such that the possibility of discontinuity of the organelle line was considered. The number of mitochondria increases dramatically during the early, meiotic prophase, with the accompanying production of profiles, which indicate that many of these newly produced organelles degenerate. It is suggested that , the degeneration observed may result from the lack of nulear-encoded regulatory molecules reaching the organelles. The association of mitochondria and nuclear envelopes in post-meiotic cells of Cosmos is the most likely evidence of direct ATP injection into the nucleus or a sign that information carrying molecules are being exported from the nucleus and passed to the organelles. Unfortunately, experiments using inhibitors suggest that this may not necessarily be the case. ' '