Fungal Mitoses, the Significance of Variations on a Theme

SUMMARY

Details of the mitotic process in the fungi differ to varying extents from those found in higher plants and animals. Examples of the more interesting deviations found in some fungi include the segregation of kinetochores into two groups during prophase, the absence of detectable chromatin condensation at any stage in the nuclear cycle, the absence of a metaphase plate, the formation of a discrete central bundle of non-kinetochore microtubules and a probable role for cytoplasmic microtubules in generating anaphase-telophase nuclear elongation. These variations are discussed in terms of the contributions they make to our understanding of how mitosis works. The above variations are only a part of a rich diversity of mitotic characteristics found among the fungi. This diversity is examined for its potential to explain both the mode of evolution of mitosis and the interrelationships of the fungi and their traditional allies. A preliminary attempt to use numerical-taxonomy techniques to achieve the latter objective is described.