Stephen Walker, PhD
Stephen Walker, Ph.D., Associate Professor
Dr. Walker received his doctorate in Genetics & Developmental Biology at West Virginia University followed by post-graduate work at Wake Forest University Health Sciences in the areas of molecular biology and proteomics. His initial faculty appointment was in the Department of Pediatrics, Section on Medical Genetics, at Wake Forest University Health Sciences. In this position he recruited families and carried out genetic association studies related to single-gene craniofacial disorders. From there he moved to the faculty in the Department of Physiology & Pharmacology where he participated in studies examining the molecular basis for substance abuse using nonhuman primate animal models. It is in this position that he was first introduced to microarray technology (looking at gene expression at the “whole transcriptome” level). Dr. Walker has been a member of the FDA-sponsored International Microarray Quality Control (MAQC) consortium since its inception in 2005. He is currently on the faculty at the Wake Forest Institute for Regenerative Medicine and is also on the Graduate faculty as well as faculty in the Neuroscience Program.
SYNOPSIS OF AREA OF INTEREST: Dr. Walker is broadly interested in using and developing molecular tools, especially array-based and sequencing technologies, to better understand transcriptional control that underlies development and disease processes.
DETAILED AREA OF INTEREST: Dr. Walker’s current research focuses on using molecular tools, including whole-genome microarrays, to understand the biological basis for autism spectrum disorders (ASDs). Two of the keys deficits in the field of ASD research are: (1) a lack of biological/molecular diagnostic criteria to better define the disorder(s) and, (2) a lack of understanding of the biological mechanisms that underlie this complex set of disorders. Much of his research in this area involves understanding how chronic gastrointestinal (GI) symptoms in ASD children are involved in the overall disease phenotype, and in identifying surrogate (molecular) markers in blood of ASD children with GI symptoms in hopes of one day eliminating the need for colonoscopy in some children. He is involved in a number of studies in both human ASD children and in animal models that are designed to address these questions.
A second focus of Dr. Walker’s research is to characterize transcriptomic profiles in cells going through various points in differentiation in an effort to better describe, through these RNA expression patterns, specific key events and characteristic profiles that define cellular status. As an example, we have used microarray profiling to show that animal oocytes do not appear to provide the signals necessary to reprogram human somatic nuclei (Chung et al., 2009).