John Tower received his PhD in 1988 from The Johns Hopkins University School of Medicine, Biochemistry, Cellular, and Molecular Biology Training Program, where he worked under the direction of Dr. Barbara Sollner-Webb on the topic of rDNA transcriptional regulation. He subsequently undertook postdoctoral training with Dr. Allan C. Spradling, at the Department of Embryology, Carnegie Institution of Washington, in Baltimore, where he began ongoing studies on Drosophila P element mutagenesis and chorion gene amplification. In 1991 he joined the faculty in the Department of Biological Sciences, University of Southern California, in what is now the Molecular and Computational Biology Program. Dr. Tower has been investigating the molecular genetics of aging in Drosophila since 1989, with a particular emphasis on transgenic technologies, hsps, superoxide dismutase, p53 and the role of sexual differentiation.
Professor Tower's research focuses on the molecular genetics of aging in Drosophila melanogaster. He is taking several approaches to his research on aging, the first of which is studying the regulation of gene expression as a function of age, in particular, the heat shock protein genes hsp70 and hsp22, and anti-microbial peptide genes involved in the innate immune response. Increased expression of these genes was found to be a predictive biomarker of aging. The second approach is to identify genes that directly regulate life span. His current emphasis is to test candidate genes involved in regulating oxidative stress responses and nuclear-mitochondrial signaling. He is particularly interested in how the post-mitotic muscle, nerve and liver cells of the adult maintain function during aging, and how stem cells populations are maintained in the ovary. These studies have identified p53 and sexual differentiation as key contributors to aging. Professor Tower is investigating how sex-specific hormones, including steroid hormones and male Sex Peptide hormone can promote sexual differentiation and reproduction at a cost for animal health and life span.