Using Drosophila to study regulation of neural stem cell quiescence by nucleocytoplasmic transport

Cellular quiescence is a reversible non-dividing state. Subsets of adult mammalian stem cells, namely neural stem cells, spend the majority of their time in quiescence. The ability of stem cells to adopt the quiescent state appears to be crucial for long-term maintenance of the stem cell compartment. Tumour cells can also become quiescent and this renders them resistance to most chemotherapeutics, which target proliferating cells. Despite its importance, the molecular mechanisms that regulate the quiescent state still remain to be fully elucidated. In particular, the use of Drosophila melanogaster as a genetic model organism has provided important insights into various molecular mechanisms and cellular processes, including neurogenesis and neural stem cell quiescence. Drosophila neural stem cells, called neuroblasts, undergo two waves of neurogenesis separated by a period of quiescence. This project aimed to study the role of nucleocytoplasmic transport in regulating neuroblast quiescence. Here, we show evidence of a role for key components of nuclear transport machinery in the regulation of neuroblast quiescence. Furthermore, we investigate nucleocytoplasmic partitioning of key regulators of growth and/or cell-cycle progression. This work provides preliminary data implicating nucleoporins and casein kinase II as determinants of the quiescent state.