Genome-Wide Analysis of Self-Renewal in Drosophila Neural Stem Cells by Transgenic RNAi

Abstract

SummaryThe balance between stem cell self-renewal and differentiation is precisely controlled to ensure tissue homeostasis and prevent tumorigenesis. Here we use genome-wide transgenic RNAi to identify 620 genes potentially involved in controlling this balance in Drosophila neuroblasts. We quantify all phenotypes and derive measurements for proliferation, lineage, cell size, and cell shape. We identify a set of transcriptional regulators essential for self-renewal and use hierarchical clustering and integration with interaction data to create functional networks for the control of neuroblast self-renewal and differentiation. Our data identify key roles for the chromatin remodeling Brm complex, the spliceosome, and the TRiC/CCT-complex and show that the alternatively spliced transcription factor Lola and the transcriptional elongation factors Ssrp and Barc control self-renewal in neuroblast lineages. As our data are strongly enriched for genes highly expressed in murine neural stem cells, they are likely to provide valuable insights into mammalian stem cell biology as well.

Differential control of Yorkie activity by LKB1/AMPK and the Hippo/Warts cascade in the central nervous system

“…3H). The difference in DIAP1 expression between type I and type II NBs might be caused by differences in gene expression between these cell types (67,77,78). Finally, we observed a dramatic increase in Yki nuclear localization in lkb1 x5 mutant NBs (92.2%) in comparison with control NBs (9.1%; Fig.…”

Evidence of asymmetric cell division and centrosome inheritance in human neuroblastoma cells

“…Although some adult stem cells divide asymmetrically in normal homeostasis, they retain the capacity to divide symmetrically to restore stem-cell pools depleted by injury or disease, as has been observed in the nervous and hematopoietic systems (10). Moreover, it is known that the balance between stem cell self-renewal and differentiation is precisely controlled and an imbalance leads to tumorigenesis in Drosophila neuroblasts (11)(12)(13). Therefore, we investigated the behavior of ACD and symmetric cell division (SCD) in human neuroblastoma cells.…”

Analysis of neural stem cell self-renewal and differentiation by transgenic RNAi in Drosophila

“…To obtain insight into these gene networks, large-scale genome-wide transgenic RNAi technology has recently been used in order to identify novel genes that are potential regulators in the self-renewal and proliferation of Drosophila neuroblasts [12,13].…”

“…Currently, three independent sources of genome-wide UAS-RNAi transgenic lines are available [Vienna Drosophila RNAi Center (VDRC), Transgenic RNAi Project (TRiP) at the Harvard Medical School, and NGI-FLY RNAi Resources in Japan], such that altogether about 90% of the annotated genes in the Drosophila genome can now be targeted by these lines [67]. With the availability of these lines, genome-wide transgenic RNAi screens have been successfully used to study Notch signaling [68,69], muscle morphogenesis and functions [70], host-pathogen interactions [71], and self-renewal of neuroblasts [12,13]. Taken together, these studies show that even very complicated biological mechanisms can be systematically analyzed at the genome-wide level by transgenic RNAi.…”

“…This has been possible due to the generation and availability of several independent genome-wide transgenic RNAi libraries, which are based on the binary Gal4/UAS expression system that allow analysis of complicated developmental processes in a targeted, tissue-specific way [10][11][12][13].…”