Mitotic spindle assembles in each blastomere to segregate duplicated chromosomes during cleavage of the fertilized egg. Here, the authors establish functional assays in fish embryos and find that Ran-GTP assembles a microtubule network at the metaphase spindle center that is essential for chromosome segregation.
- Ai Kiyomitsu
- Toshiya Nishimura
- Tomomi Kiyomitsu
