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. The cytochrome P450s (CYP) are one of the key enzymes induced by xenobiotic-sensing nuclear receptors, and an enzyme family of special interest in our research.  We use a variety of techniques including lifecycle testing, transactivation assays, transgenic technologies, bioinformatics, and transcriptomics to study how organisms adapt to toxicants.


  1. We study the interplay between toxicant exposure and high-fat diet in the development of non-alcoholic fatty liver disease and obesity. We are especially interested in chemicals that modulate CYP activity.  We often use newly constructed knockout and humanized mouse models to perform this work.   
  2. 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 recognize a variety of toxicants and help Daphnia acclimate to toxicant stress. 
  3. 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 environmental 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.   

Selected Publications

  • *Sengupta, N., **Litoff, E.J., Baldwin, W.S. (2015) The HR96 activator, atrazine, reduces sensitivity of D. magna to triclosan and DHA.  Chemosphere, 128, 299-306.
  • *Ginjupalli, G.K., Gerard, P.D., Baldwin, W.S., (2015) Arachidonic acid enhances reproduction in Daphnia magna and mitigates changes in sex ratios induced by pyriproxyfen.  Environ Toxicol Chem, 34, 527-535.
  • **Litoff, E.J., **Garriott, T.E., *Ginjupalli, G.K., **Butler, L, **Gay, C., **Scott, K., Baldwin, W.S.  (2014) Annotation of the Daphnia magna nuclear receptors:  Comparison to the distantly related cladocern, Daphnia pulexGene, 552, 116-125.
  • *Li, Y, *Gingupalli, GK, Baldwin, WS.  (2014) The HR97 (NR1L) group of nuclear receptors:  A new group of nuclear receptors discovered in Daphnia species.  Gen Comp Endocrinol, 206:  30-42.
  • *Karimullina, 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. 
  • *Mota, L.C., *Hernandez, J.P., Baldwin, W.S.  (2010) Constitutive androstane receptor-null mice are sensitive to the toxic effects of parathion:  Association with reduced CYP-mediated parathion metabolism.  Drug Metab Dispos. 38:  1582-1588.  
  • 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. 
  • Baldwin, W.S., Marko, P.B., Nelson, D.R. (2009) The cytochrome P450 (CYP) gene superfamily in Daphnia pulexBMC Genomics.  10:169.
  • 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.

Recent Courses

  • BIOL 1030:  General Biology
  • ENTOX/BIOSC 8300:  Mechanistic Toxicology
  • BIOL 4800/6800:  Endocrinology
  • BIOL 8440:  Understanding Human Biosystems

Graduate Students

  • Namrata Sengupta
  • Ramiya Kumar
  • Allison Schmidt

Professional Affiliations

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