PCNE · Plasticity of nuclear cycling in response to the environment

The traditional view of proliferation in eukaryotic cells maintains that genome duplication is followed by cellular division into two new daughter cells, each containing its own nucleus. Organisms have evolved diverse strategies to accomplish this feat efficiently whilst acted upon by different selection pressures, some of which alter the mode of proliferation altogether. Strikingly, several organisms across the tree of life have evolved to utilize the multiplication of genetic material without the generation of new daughter cells as a successful replicative strategy. Although the nuclei reside in a shared cytoplasm, the dynamics of the nuclear cycles of multinucleate cells vary across organisms, from synchronicity, such as in the Drosophila embryo, to asynchronous replication as in the filamentous fungi Ashbya gossypii. While the fast, synchronized divisions in developing Drosophila embryos are hypothesized to benefit growth speeds, asynchronous divisions are hypothesized to balance replication speed with resource availability. While it is evident that the efficient use of resources for regulating the cell cycle control network is fundamental for survival and adaptation to the environment, the factors and molecular mechanisms regulating autonomous nuclear cycles in multinucleate cells are largely unknown. Using a combination of multiplexed spatial transcriptomics, classic cell biology approaches, high-resolution imaging, and molecular genetics, the proposed project will elucidate the extent to which the environment influences nuclear cycling in two evolutionarily distant eukaryotes, the free-living slime mold, Physarum polycephalum and the intracellular parasite, Plasmodium falciparum.