报告题目：Systems-level analysis of spatial and temporal coordination during fate specification during animal embryogenesis, a quantitative perspective
内容摘要: Development of multicellular animals demands not only precise control over cell fate specification but also on accurate regulation of cell division pace and cell migration to ensure proper development. How cell divisions are spatially and temporally coordinated to accommodate cell fate specification during development is poorly understood. C. elegans embryogenesis provides an excellent opportunity to address these questions due to its invariant fate development and consistent cell division paces relative to each other. On top of these, its transparent embryo with fast developing speed (roughly 14 hours at room temperature) allows in vivo visualization of live cell division throughout embryogenesis. A combination of 3D time-lapse fluorescence microscopy and customized software permits automated identification and tracking of cell divisions and fate specification. Leveraged on these tools, we previously knockdown a total of 822 essential and conserved genes using RNAi to screen for genes that are not only required for breaking cell fate symmetry, but also for establishing division timing asymmetry. We demonstrated that the same regulatory schemes were used for breaking the both symmetries. Mining of the division defects in mutant embryos allows us to dissect the genetic control over the intestine-specific delay of division paces relative to the remaining cells. Intriguingly, knockdown of numerous genes encoding the components of general transcription pathway or its regulatory factors leads to a significant reduction in the cell cycle length of intestine stem cells but an increase in cell cycle length of the remaining cells, indicating a differential requirement of transcription for division pace between the two types of cells. The reduction in intestine cell cycle length is frequently associated with cell migration defect and gastrulation failure. The results suggest that a tissue-specific transcriptional activation is required to coordinate fate differentiation, division timing, and cell migration to ensure proper development. To further illustrate the coordination between cell division pace and fate specification, we have recently developed cell-cycle specific markers, which allows precise monitoring of cell cycle progression during fate specification. The combination of the fate and cell cycle markers along with genetic manipulation paves the way for study of coordination between cell cycle progression and cell fate specification in a developing embryo, which could be insightful of tissue-specific origin of cancer. The preliminary data on the coordination between cell cycle progression and cell fate specification will be presented..
报告人简介：赵中应博士毕业于 Simon Fraser大学，并在 University of Washington从事过博士后工作。现为香港浸会大学生物系副教授，主要研究兴趣有Mechanism of postzygotic hybrid incompatibilities between nematode species， Developmental dynamics of signaling pathways during nematode embryogenesis， Gene regulatory networks underlying cell fate determination during nematode embryogenesis。已在PNAS, Nature Methods, Genome Research, Molecular Systems Biology, Plos Genet, Nucleic Acids Res, Genome Biology等顶级期刊发表论文多篇。