dwalker@mail.utexas.edu
Ph.D. 2012, Institute for Neuroscience
Background:
I graduated from UT in 2002 with a B.S. in biology. As an undergraduate, I worked under Dr. Tom Mabry studying the estrogenic nature of compounds extracted from several plant species native to central Texas. Following this, I began research in the lab of Dr. Su Dharmawardhane and was given an independent project determining the role of TGF-Beta in breast cancer metastasis. In addition to my work in research laboratories, I worked with Dr. Delia Brownson, supervising the preparations for the upper and lower-division molecular biology lab courses at UT-Austin.
After graduation, I was hired as a technician in Dr. Cheryl Walker’s laboratory at the MD Anderson Cancer Center, Research Division in Smithville, TX. While there, I studied the effects of diethylstilbesterol (DES) on the development of uterine leiomyomas in rats. The research I conducted in Dr. Walker’s lab was instrumental in establishing an interest in endocrine disrupting chemicals (EDCs) and their effects on the developing fetus.
I worked for two years as a technician in Dr. Gore’s laboratory prior to graduate school. While there, I served as the molecular biology specialist for the lab. I established a real-time PCR protocol and developed assays to substitute for our RNase Protection Assay (RPA) protocols, such as assays measuring the primary transcript for GnRH. I was involved in a number of molecular based projects, but was interested in those projects concerning EDCs and development in rats. I completed my own project which sought to elucidate the role of GnRH gene expression in pubertal development in male rats using real-time PCR.
Research:
I started graduate school in 2006. Since being in graduate school, I have expanded my interest in the molecular mechanisms underlying the onset of puberty in rats by studying gene expression changes in sex steroid hormone receptors in the developing preoptic area. Along with Lorenzo Perez, an undergraduate in our lab, I have also begun work identifying sex differences in gene expression in both the preoptic area and the medial basal hypothalamus. We are also interested to determine if the changes in gene expression that we have observed are associated with changes in serum hormone concentrations. Finally, I would like to determine if developmental exposure to EDCs can alter the gene expression profiles in both male and female rats. Together, I hope these studies will help to identify basic molecular mechanisms required for the onset of puberty in mammals.
Published Papers:
- Walker DM, Gore AC (2007) Endocrine-disrupting chemicals and the brain. In: Gore AC (ed), Handbook of Endocrine-disrupting Chemicals, Humana Press, pp 63 – 109.
- Dickerson SM, Walker DM, Reveron ME, Duvauchelle CL, Gore AC (2008) The recreational drug ecstasy disrupts the hypothalamic-pituitary-gonadal reproductive axis in adult male rats. Neuroendocrinology 88(2):95-102.
- Maffucci JA, Walker DM, Ikegami A, Woller MJ, Gore AC (2008) The NMDA receptor subunit NR2b: Effects on LH release and GnRH gene expression in young and middle-aged rats, with modulation by estradiol. Neuroendocrinology 87(3):129-41.
- Steinberg RM, Walker DM, Juenger TE, Woller MJ, Gore AC (2008) The effects of perinatal PCBs on adult female reproduction: Development, reproductive physiology, and second generational effects. Biology of Reproduction 78(6):1091-101.
- Walker DM, Juenger TE, Gore AC (2009) Developmental profiles of neuroendocrine gene expression in the preoptic area in the male rat. Endocrinology 150: 2308-2316.