Qi-Long Ying


Associate Professor

Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC
Department of Cell & Neurobiology
Keck School of Medicine

Research Topics

  • Cellular Neurobiology
  • Developmental Biology
  • Signal Transduction
  • Stem Cell Biology

Research Overview

Embryonic stem (ES) cells are remarkable cell lines that are derived from the inner cell mass of pre-implantation embryos. They can be grown indefinitely in culture while retaining the capacity to differentiate into all the cells of the body. When reintroduced into early stage embryos, ES cell can reenter normal developmental processes and contribute to all lineages including germ cells. This differentiation potential makes ES cells a possible source for future cell replacement therapies. The process in which pluripotent ES cells differentiate into progenitors with a more restricted developmental potential and then to terminally differentiated cells is predictable and controllable. This means ES cells are also an ideal model for the study of the molecular and epigenetic events that occur during this differentiation process.

My research focuses on understanding the molecular mechanism underlying ES cell self-renewal and differentiation. When an ES cell divides it can either produce identical copies of itself (self-renewal) or it can produce other more specialized cell types (differentiation) such as neurons. Understanding how an ES cell makes this choice between self-renewal and differentiation is the central challenge in stem cell research. We recently identified a novel regulatory pathway that promotes the multiplication of pure populations of mouse embryonic stem cells. This discovery allowed for the first time growth of embryonic stem cells in fully defined medium. I am also interested in finding out the molecular basis underlying the difference between mouse and human ES cells in their requirement for extrinsic stimuli that sustain pluripotency