Dividing to their own beat

Multiple fungal nuclei within a common cytoplasm divide independently, based on findings on page 347. Gladfelter et al. suggest that the Ashbya gossypii filamentous fungus evolved a new means to control cyclin activity that might make asynchronous nuclear division possible.

Cyclin activity drives the mitotic cycle in eukaryotes. To prevent untimely mitosis, most cells degrade mitotic cyclins at telophase and show an oscillating pattern of cyclin protein levels. As cyclins can enter and exit nuclei and diffuse throughout the cytoplasm, multinucleated cells normally have synchronous nuclear divisions.

But the new report shows that A. gossypii nuclei divide independently of their neighbors. Nuclei at various stages of the cell cycle were found within single cells. Artificially synchronized nuclei did not remain in synch for long, suggesting that each nucleus...