Everett E. Just Lecture (02 December 2007)

5 December 2007

Nancy R. Gough

ASCB president Bruce Alberts presented Alejandro Sánchez Alvarado (University of Utah) with the Everett E. Just Award. Following a few remarks about what the award meant to him, Dr. Alvarado spoke about his work studying regeneration of the planarium Schmidtea meterranea. This organism has remarkable regenerative capacity, which has been known for centuries, and includes the ability for a very small piece (1/279th) of the organism to completely regenerate. The genome of this organism has now been sequenced and annotated and, surprisingly, it contains the same complement of 13 homeobox genes that are found in vertebrates. He described his work to identify and characterize the stem cells responsible for this regenerative response. These stem cells are the only dividing cells in the organism and the two regions that lack these cells are the only ones that do not regenerate. Irradiation of the animals to destroy the stem cells results in wound closure following amputation, but no regeneration. Using RNAi techniques, he found what appears to be a new pathway leading to β-catenin activation that is required for formation and maintenance of tail structures in these organisms. (see the Science article by Alvarado)