MTOControl · Spatiotemporal coordination of microtubule-organizing centers in two evolutionary distant eukaryotes

Spatiotemporal coordination of microtubule-organizing centers in two evolutionary distant eukaryotes

Green algae play a significant role in the global CO2 absorption, removing this greenhouse gas from the atmosphere and using it for photosynthesis. To keep the atmosphere balanced, especially with the growing challenges of climate change, it is important to understand the basic cell biology of green algae proliferation: their cell cycle and especially their mitosis and cell division. During mitosis, a massive reorganization of the microtubule cytoskeleton is critical to ensure mitotic spindle formation, proper segregation of chromosomes and, finally, cell division. In animals, the main microtubule organizing center (MTOC) coordinating microtubules is the centrosome, which contains a central pair of so-called centrioles, cylindrical, complex structures made of microtubules. During mitosis in animals, centrosomes are positioned at the two poles of the mitotic spindle, organizing spindle microtubules. In the evolution of land plants, centrioles were lost and spindle microtubules were organized by a centriole-free, dispersed MTOC. In the eukaryotic tree of life, green algae are in an interesting position “in between” animals and land plants to understand evolution of MTOCs in the green lineage and the impact on mitosis. The unicellular green algae model organism, Chlamydomons reinhardtii, has retained animal-like centrioles which were often assumed to act as MTOCs for mitotic spindle microtubules in the alga. However, there is a clear gap between mitotic spindle poles and the position of the centrioles in the alga cell, questioning whether centrioles are the MTOCs of spindle microtubules in Chlamydomonas. Instead, a second, separated MTOC might coordinate microtubules of the mitotic spindle. In this project, I investigated the dynamics and ultrastructural organization of mitosis, centrioles and associated structures in the green alga Chlamydomonas reinhardtii to understand how the green alga proliferates and which role different MTOCs play during mitosis of the alga in comparison to animals and land plants. The results of my project will help to understand evolution and diversity of MTOC and mitosis biology in green algae and might ultimately give a new view on how the dispersed MTOC of land plants evolved.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз