TALK SUMMARY: It is paradoxical that for many animal (including humans), the apparent anatomical stability of their adult bodies is maintained by constant change. Under normal physiological conditions, the functions of many organs depend on the continuous destruction and renewal of their cells. Equally remarkable is the fact the adult tissues and organs of many organisms can be fully restored after amputation.

In fact, it appears that metazoans have evolved a series of renewal and repair mechanisms to respond to both trauma and normal wear and tear. Moreover, these mechanisms are under tight regulatory control such that organismal form and function can be maintained throughout life. As important as repair and restoration are to survival of multicellular organisms, we know little about how these processes are effected and regulated at the cellular and molecular levels.

Here, I will discuss how the study of a simple metazoan, the planarian Schmidtea mediterranea, is beginning to shed light on the way adult animals regulate tissue homeostasis and the replacement of the body parts lost to injury.

BIOGRAPHICAL SKETCH: Alejandro Sanchez Alvarado was born in Caracas, Venezuela. He received his Bachelor's Degree in Molecular Biology and Chemistry from Vanderbilt University in 1986. In 1992, he received his Ph.D. in Pharmacology and Cell Biophysics at the University of Cincinnati School of Medicine, where he studied mouse ES cells and their in vitro differentiation under the tutelage of Dr. Jeffrey Robbins and Thomas Doetschman.

In 1994, he joined the laboratory of Dr. Donald Brown at the Carnegie Institution of Washington Department of Embryology as a postdoctoral fellow, and in 1995 was appointed Staff Associate. It was during third period that Dr. Sanchez Alvarado began to explore system in which to molecularly dissect the problem of regeneration. In 2002 he became an Associate Professor at the Department of Neurobiology and Anatomy at the University of Utah School of Medicine, and in 2005 he was promoted to Professor and appointed a Howard Hughes Medical Institute Investigator. His current efforts are aimed at elucidating the molecular basis of regeneration using the free-living flatworm Schmidtea mediterranea.

For more information, visit http://planaria.neuro.utah.edu/