At the fall 2014 meeting, the HRP consortium realized that we lacked an important genomics dataset, which would characterize at a molecular level how supporting cells respond to immediate death of hair cells. Using a mouse model developed by Ed Rubel, an HRP investigator, this project will examine how RNA expression changes in mice whose hair cells are killed with an application of diphtheria toxin. These “DTR mice” respond to the diphtheria toxin because all of their hair cells are uniquely sensitive to the toxin because of expression of a specific receptor. We will be able to compare the responses of supporting cells to the toxin with responses to hair cell death from aminoglycosides, already carried out by this group.