Environmental and developmental toxicology
Francis is an environmental toxicologist whose work focuses on the irreversible effects of pesticides. One focus of her research is on alterations in gene expression following exposure to environmental agents (broadly defined). By using chemicals that affect gene expression (e.g., retinoic acid) and cause malformations in experimental animals, she attempts both to identify mechanisms by which developmental toxicants cause malformations, and to identify genes acting in normal development.
Francis also has a strong interest in pesticide in toxicology, and especially their irreversible effects. Such studies often intersect the developmental studies. For example, the herbicide nitrofen (2,4-dichlorophenyl 4'-nitrophenyl ether) causes a unique constellation of defects in rodents that is highly suggestive of perturbed gene expression as a primary mechanism.. Nitrofen causes malformations of the kidneys, heart, diaphragm, and Harderian glands if administered to mice on gestational day (GD) 8 development. It does not cause limb malformations, even though our experience shows that most teratogens that cause cell death or decrease cell proliferation will cause limb malformations on GD 8.
Another example is the delayed paralysis that follows exposure to some organophosphorus esters (OPs). In humans, both adults and children can be affected, although children seem to be less sensitive. In chickens, only mature fowl become paralyzed -- chicks do not. However, when chick embryos or very young chicks are exposed to such OPs, long-lastin functional deficits result. In some cases, birds remained abnormal even as adults. Neither the mechanism for the adult paralysis nor for the develmental effects is known.
Additional pesticide studies include comparison of structure-activity relationships among nitrofen analogs and examination of the possibility that pesticides cause endocrine disruption, either by altering estrogen metabolism (DDT) or thyroid function (nitrofen) in developing fetuses and their dams.
Finally, Francis remains interested in the ecological effects of pesticide use, and uses the Metcalf microcosm to investigate these.
PhD, 1971, University of Michigan, Ann Arbor
Additional Campus Affiliations
Associate Professor Emerita, Entomology
Chernoff, N., Hill, D. J., Diggs, D. L., Faison, B. D., Francis, B. M., Lang, J. R., Larue, M. M., Le, T. T., Loftin, K. A., Lugo, J. N., Schmid, J. E., & Winnik, W. M. (2017). A critical review of the postulated role of the non-essential amino acid, β-N-methylamino-L-alanine, in neurodegenerative disease in humans. Journal of Toxicology and Environmental Health - Part B: Critical Reviews, 20(4), 183-229. https://doi.org/10.1080/10937404.2017.1297592
Francis, B. M. (2017). Reproductive toxicology of trichothecenes. In V. R. Beasley (Ed.), Trichothecene Mycotoxicosis: Pathophysiologic Effects (1989) (Vol. 1, pp. 143-159). (CRC Press Revivals). CRC Press. https://doi.org/10.1201/9781315121284
Lehmann, G. M., Verner, M. A., Luukinen, B., Henning, C., Assimon, S. A., Lakind, J. S., Mclanahan, E. D., Phillips, L. J., Davis, M. H., Powers, C. M., Hines, E. P., Haddad, S., Longnecker, M. P., Poulsen, M. T., Farrer, D. G., Marchitti, S. A., Tan, Y. M., Swartout, J. C., Sagiv, S. K., ... Simmons, J. E. (2014). Improving the risk assessment of lipophilic persistent environmental chemicals in breast milk. Critical Reviews in Toxicology, 44(7), 600-617. https://doi.org/10.3109/10408444.2014.926306
Powers, L. E., Hofmann, J. E., Mengelkoch, J., & Francis, B. M. (2013). Temporal variation in bat wing damage in the absence of white-nose syndrome. Journal of wildlife diseases, 49(4), 946-954. https://doi.org/10.7589/2012-02-034
Yi, S. A., Francis, B. M., Jarrell, W. M., & Soucek, D. J. (2011). Toxicological effects of the aquatic herbicide, fluridone, on male water mites (Hydrachnidiae: Arrenurus: Megaluracarus). Ecotoxicology, 20(1), 81-87. https://doi.org/10.1007/s10646-010-0558-0