William S. Baldwin


Contact Information

Office: 235 Long Hall
Lab: 318 Jordan
Phone:  864-656-2340
Fax:  864-656-0435
E-mail:  Baldwin@clemson.edu


  • B.S. in Biology (Chemistry minor), Central Michigan University, 1989
  • Ph.D. in Toxicology, North Carolina State University, 1995
  • Post-doctoral Fellow, Molecular Carcinogenesis, National Institute of Environmental Health Sciences, 1997

Research Interests

My research focuses on an organism’s ability to adapt to environmental stressors such as foreign chemicals and toxic endobiotics. Nuclear receptors such as CAR and PXR in mammals and HR96 in invertebrates are important in inducing protective enzymes and helping organisms acclimate to environmental stressors. We use a variety of techniques including lifecycle testing, transactivation assays, transgenic technologies, siRNA, bioinformatics, microarrays and Q-PCR to study how organisms adapt to toxicants. In turn, we are involved in the Fundulus and Daphnia Genomics Consortiums. Current projects are listed below.

  1. We study how the aquatic invertebrate, Daphnia magna adapts to environmental stressors. Our current project investigates the role of the recently annotated orphan nuclear receptors from Daphnia that putatively recognize a variety of toxicants and help this important crustacean adapt to toxicant stress. 
  2. We study the role of the nuclear receptors CAR and PXR, and their regulation of the cytochrome P450 (CYP) enzymes they induce in order to help an organism respond to toxicants.  In addition, we are evaluating the role of the Cyp2b subfamily, a key enzyme group induced by CAR, in metabolizing chemicals to less or more toxic intermediates.  We use newly constructed transgenic models to perform this work.   
  3. We foresee that in the near future we may spend more time evaluating connections between toxicant exposure and diet.

Selected Publications

  • Karamullina, E., Li, Y., Ginjupalli, G.K., Baldwin, W.S. (2012) Daphnia HR96 is a promiscuous xenobiotic and endobiotic nuclear receptor. Aquat Toxicol., 116-117, 69-78.
  • Damiri, B., Holle, E, Yu, X, Baldwin, WS. (2012) Lentiviral-mediated RNAi knockdown yields a novel mouse model for studying Cyp2b function. Toxicol Sci., 125:368-381.
  • Rungta, P., Bandera, Y.P., Roeder, R.D., Li, Y., Baldwin, W.S., Sharma, D., Sehorn, M.G., Luzinov, I., Foulger, S.H. (2011) Selective imaging and killing of cancer cells with protein activated near-infrared fluorescing nanoparticles. Macromol. Biosci., 11:927-37.
  • Mota, L.C., Hernandez, J.P., Barfield, C., Baldwin, W.S. (2011) Nonylphenol-mediated CYP induction is PXR-dependent: The use of humanized mice and human hepatocytes suggests that hPXR is less sensitive than mouse PXR to nonylphenol treatment. Toxicol Appl Pharmacol. 252: 259-267.
  • Mota, L.C., *Hernandez, J.P., Baldwin, W.S. (2010) CAR-null mice are sensitive to the toxic effects of parathion: Association with reduced CYP-mediated parathion metabolism. Drug Metab Dispos. 38: 1582-1588.
  • Gonzalez, H.O., Hu, J, Gaworecki, K.M., *Roling, J.A., Baldwin, W.S., Gardea-Torresdey, J.L., Bain, L.J. (2010) Dose-responsive gene expression changes in juvenile and adult mummichogs (Fundulus heteroclitus) after arsenic exposure. Mar Environ Res. 70: 133-141.
  • Hannas, B.R., Wang, Y.H., Baldwin, W.S., *Li, Y., Wallace, A.D., LeBlanc, G.A. (2010) Interactions of the crustacean nuclear receptors HR3 and E75 in the regulation of gene transcription. Gen Comp Endocrinol. 167: 268-278.
  • Van Aggelen, G, Ankley, G.T., Baldwin, W.S., Bearden, D.W., Benson, W.H., Chipman, K., Collette, T.W., Craft, J.A., Denslow, N.D., Embry, M.R., Falciani, F., George, S.G., Helbing, C.C., Hoekstra, P.F., Iguchi, T., Kagami, Y., Katsiadaki, I., Kille, P., Liu, L., Lord, P.G., McIntyre, T., O’Neill, A., Osachoff, H., Perkins, E.J., Santos, E.M., Skirrow, R.C., Snape, J.R., Tyler, C.R., Versteeg, D., Viant, M.R., Volz, D.C., Williams, T.D., Yu, L. (2010) Integrating omic technologies into aquatic ecological risk assessment and environmental monitoring: Hurdles, achievements and future outlook. Environ Health Perspect. 118: 1-5.
  • Thomson, SA, Baldwin, WS, Wang, YH, Kwon, G, LeBlanc, GA. (2009) Annotation, phylogenetics, and expression of the nuclear receptors in Daphnia pulex. BMC Genomics, 10: 500. PMCID: PMC2774871
  • Hernandez, JP, Mota, LC, Baldwin, WS. (2009) Activation of CAR and PXR by Dietary, Environmental and Occupational Chemicals Alters Drug Metabolism, Intermediary Metabolism, and Cell Proliferation. Curr Pharmacog Person Med. 7: 81-105.
  • Baldwin, W.S., Marko, P.B., Nelson, D.R. (2009) The cytochrome P450 (CYP) gene superfamily in Daphnia pulex. BMC Genomics. 10:169.
  • Hernandez, JP, Mota, LC, Huang, W, Moore, DD, Baldwin, WS (2009) Sexually dimorphic regulation and induction of P450s by the constitutive androstane receptor (CAR). Toxicology, 256: 53-64.
  • Baldwin, W.S. and Roling, J.A. (2009) A concentration addition model for the activation of the constitutive androstane receptor by xenobiotic mixtures. Toxicol Sci. 107: 93-105.
  • Hernandez, J.P., Huang, W., Chapman, L.M., Chua, S., Moore, D.D, Baldwin, W.S. (2007) The environmental estrogen, nonylphenol, activates the constitutive androstane receptor (CAR). Toxicol. Sci., 98: 416-426.
  • Roling, J.A., Bain, L.J., Gardea-Torresdey, J., Key, P.B., Baldwin, W.S. (2007) Using mummichog (Fundulus heteroclitus) arrays to monitor the effectiveness of remediation at a superfund site in Charleston, South Carolina. Environ Toxicol Chem., 26: 1205-1213.
  • Acevedo, R., Villanueva, H., Parnell, P.G., Chapman, L.M., Gimenez, T., Gray, S.L., Baldwin, W.S. (2005) The contribution of hepatic steroid metabolism to serum estradiol and estriol concentrations in nonylphenol treated MMTVneu mice and its potential effects on breast cancer incidence and latency. J. Appl. Toxicol., 25, 339-353.
  • Kretschmer, X.C., Baldwin, W.S. (2005). CAR and PXR: Xenosensors of Endocrine Disrupters? Chem-Biol. Interac., 155, 111-128.

Recent Courses

  • BIOL 103:  General Biology
  • ENTOX/BIOSC 830:  Mechanistic Toxicology
  • BIOSC/AVS 480/680:  Vertebrate Endocrinology
  • BIOSC 844:  Understanding Human Biosystems

Graduate Students

  • Namrata Sengupta
  • Gautam Ginjupalli

Professional Affiliations

  • Society of Environmental Toxicology and Chemistry (1990-present)
  • Society of Toxicology (1993-present)