Updated: December 5, 2015
CBC Scholar: Class of 2011
PhD Candidate, Committee on Development, Regeneration and Stem Cell Biology (BSD), UChicago, Advisor: Robert Ho
HO LAB WEBPAGE
On June 11, 2013, Qiyan successfully defended her thesis: "Spatial dynamics and regulation of the zebrafish limb morphogenetic field." Congratulations!
How cells organize to shape the embryo is a central question in developmental biology. Cell migration ubiquitous presents in diverse morphogenesis processes and constitutes a key mechanism of cell organization. The vertebrate limb bud is a classic model in developmental genetics. Though genetic mechanisms orchestrating limb bud development has been detailed, surprisingly little is known about the cellular mechanism of its morphogenesis. It has been long considered that the limb bud arise solely from the onsite proliferation of lateral plate mesoderm cells. However, a previous study from our lab has suggested that cell migration is involved during formation of the pectoral limb bud in zebrafish, a process requiring Tbx5a function.
We combine single-cell labeling-based fate mapping and 4D cell tracking to trace cell migration in the zebrafish pectoral limb field. During the past one year, we developed a semi-automatic 4D cell tracking approach to analyze trajectories of limb field cells. First, we obtained 4D datasets (XYZT) from double transgenic embryos with an LPM marker and a nucleus marker on a spinning disk confocal microscope. Next, we manually tracked XY spots based on locations of LPM cell nucleus on maximum intensity projections (MIP) along Z-axis. Then with a customly developed ImageJ macro, we generated XYZ spots by automatically obtaining the Z-position of each XY spots from the original XYZT dataset. Subsequently, we fitted a 3D surface to all XYZ spots via parabolic regression for the orthogonal XY and XZ planes to mimic the curvature of the yolk ball and to generate fitted XYZ cell tracks. Finally, to reduce dimensionality and to facilitate comparisons between embryos, we carried out a “digital flat mount” procedure to transform XYZ tracks into XY tracks. With the new technique, we can rapidly analyze cell motility in multiple genetic background in parallel.
Mao Q, Stinnett HK, Ho RK. Asymmetric cell convergence-driven fin bud initiation and pre-pattern requires Tbx5a control of a mesenchymal Fgf signal. Development. 2015 Nov 2. [Epub ahead of print] (PubMed)
AWARDS AND SERVICE:
- Travel Award for presentation at the 12th International Conference on Limb Development and Regeneration at Mont-Tremblant Qc, 3-6 June 2012
- 1st place Presentation Award for research talk “Coordinated Cell Convergence Drives Zebrafish Pectoral Limb Bud Initiation” at the 50th Annual Midwest Developmental Biology Meeting, May 11-12, 2012, Cincinnati, Ohio
- Judge, Chicago Public Schools Student Science Fair, March 2012
- CBC Scholar 2011-2012
- Certificated participation: Gordon Research Conference: Cell Contact & Adhesion 2011
- Certificated completion: Professional Grant Developmental Workshop 2011
- Community services: Student judge at Chicago Public School Science Fair 2011
- University services: Executive board member at University of Chicago Biotechnology Association