After graduating from Hangzhou University, China in 1982, Xiaohang Yang was honored as a CUSBEA student and went to the United States for graduate study in1983. He received his PhD from Dartmouth College in 1988 and worked as a postdoctoral research associate at the Massachusetts Institute of Technology before joining the IMCB in late 1989. He received the distinguished Lee Kuan Yew research fellowship in 1991 and shared Singapore National Science award in 2001. He is now an Associate Professor.

Asymmetric cell division is a common process involved in stem cell self-renewing and differentiation. Drosophila melanoglaster represents a unique and convenient model system for asymmetric cell division study. During Drosophila embryonic neurogensis, neural stem cells divide asymmetrically to produce two daughters with distinct cell sizes. The large cell remains as the stem cell and will continue to divide asymmetrically. The small one becomes the ganglion mother cell and divides terminally to form two neurons. In mitotic neural stem cells, two groups of proteins are asymmetrically localized to either apical or basal cortex of the cell. Baz, Par6, DAPKC, Insc, Pins and Gαi, as well as Loco, are concentrated on the apical cortex while cell fate determinants Numb and Pros, together with their adapter proteins Pon and Mira, are restricted to the basal cortex. The apically localized proteins form a functional complex (apical complex) which controls Numb and Pros basal localization; orients mitotic spindle position and promotes spindle asymmetry.

We are interested in the mechanism of neural stem cell asymmetric division and are taking a combination of genetic, molecular and cell biology approaches to identify new players involved in this process. We are currently characterizing several candidate genes isolated from a previous microarray screen. Other ongoing projects in the lab include a genetic screen with RNAi flies, TAP-fusion protein pulldown experiments and a microarray screen identifying proteins commonly controlled by the Snail family proteins. We hope that the novel proteins isolated from these screens will help us understand further the mechanism of neural stem cell asymmetric division.