Xiao-jiang Quan

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A comprehensive systems-level understanding of developmental programs requires the mapping of the underlying gene regulatory networks. While significant progress has been made in mapping a few such networks, almost all gene regulatory networks underlying cell-fate specification remain unknown and their discovery is significantly hampered by the paucity of(More)
How conserved pathways are differentially regulated to produce diverse outcomes is a fundamental question of developmental and evolutionary biology. The conserved process of neural precursor cell (NPC) selection by basic helix-loop-helix (bHLH) proneural transcription factors in the peripheral nervous system (PNS) by atonal related proteins (ARPs) presents(More)
Neuronal specification is regulated by the activity of transcription factors containing the basic helix-loop-helix motif (bHLH); these regulating proteins include, among others, the neurogenin (Ngn) family, related to the atonal family of genes. Neurogenin 1 (NGN1) is a 237-residue protein that contains a bHLH domain and is involved in neuronal(More)
BBP proteins constitute a subclass of CUL3 interacting BTB proteins whose in vivo function remains unknown. Here, we show that the Xenopus BBP gene BTBD6 and the single Drosophila homologue of mammalian BBP genes lute are strongly expressed in the developing nervous system. In Xenopus, BTBD6 expression responds positively to proneural and negatively to(More)
Genetic screens are powerful methods for the discovery of gene-phenotype associations. However, a systems biology approach to genetics must leverage the massive amount of "omics" data to enhance the power and speed of functional gene discovery in vivo. Thus far, few computational methods for gene function prediction have been rigorously tested for their(More)
It is now widely recognized that as cells of developing tissues transition through successive states of decreasing pluripotency into a state of terminal differentiation, they undergo significant changes in their gene expression profiles. Interestingly, these successive states of increasing differentiation are marked by the spatially and temporally(More)
Neurogenesis is initiated by the transient expression of the highly conserved proneural proteins, bHLH transcriptional regulators. Here, we discover a conserved post-translational switch governing the duration of proneural protein activity that is required for proper neuronal development. Phosphorylation of a single Serine at the same position in Scute and(More)
The neurogenin (Ngn) transcription factors control early neurogenesis and neurite outgrowth in mammalian cortex. In contrast to their proneural activity, their function in neurite growth is poorly understood. Drosophila has a single predicted Ngn homolog, Tap, of unknown function. Here we show that Tap is not a proneural protein in Drosophila but is(More)
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