Role of nucleoporin Nup98 in the nuclear differentiation process of ciliated protozoa

核孔蛋白Nup98的核特异性同源物可以区分四膜虫的大核（MAC）和微核（MIC）。在这项研究中，我们研究了核分化过程中Nup98的动态行为。我们观察到，MAC型Nup98开始组装后，立即在最后一次有丝分裂结束的合子后核的未来MAC的外围。这个时间比MAC核分化所需的因子的核运输早约30分钟。这些结果表明，放置MAC NPC含有MAC型Nup98是第一个不同的事件触发进一步MAC分化，可能是通过导致MAC选择性核转运。

The macronucleus (MAC) and the micronucleus (MIC) of ciliate Tetrahymena thermophila can be distinguished by nucleus-specific homologues of nucleoporin Nup98. In this study, we examined the dynamic behavior of the Nup98s during nuclear differentiation. We observed that MAC-type Nup98 started to assemble on the periphery of the future MACs immediately after the end of the last mitotic division of postzygotic nuclei. This timing was about 30 min earlier than the nuclear transport of factors required for MAC nuclear differentiation. These results suggest that placement of the MAC NPC containing MAC-type Nup98 is the first distinct event triggering further MAC differentiation, probably by leading to MAC-selective nuclear transport.