My laboratory studies organ formation processes including organ size control and morphogenesis through a combination of Drosophila genetics and quantitative biology methods.

1. Over the past two decades, it has become clear that cell structural proteins, including both cytoskeletal proteins and cell polarity complexes, are important for organ size control.  For example, my group, and others, have independently shown that the cytoskeletal spectrin network modulates Hippo signaling activity and regulates organ size (Wong et al., 2015). The Scribble (Scrib) protein is an example of cell polarity proteins essential for organ size control. We have recently demonstrated that the homozygous scrib mutants exhibit a high degree of plasticity along the temporal axis through longitudinal bulk and single-cell transcriptomic analysis (Ji et al, 2019; Deng et al, 2019). We are currently exploring how highly conserved growth-regulatory signals, including JNK, ERK, Notch, JAK/STAT, Hippo, Insulin and Toll pathways, form a dynamic and quantitatively-refined signaling network that modulates tumor cell plasticity and leads to two opposite growth outcomes (tumorigenesis vs cell death).

2. My group has previously established Drosophila embryonic neuroblasts as a system to study single cell delamination. Through quantitative live imaging analysis, we have found that quantitative differences in medial myosin pulse amplitude and frequency are critical to distinguish delaminating neuroblasts from their neighbors (An et al, 2017). We are investigating how differential Notch signaling activities between delaminating neuroblasts and their neighbors is interpreted to set up a highly dynamic and quantitatively refined actomyosin pattern across the epithelial tissue. 

© 2020 by Y. YAN