Elissa A Hallem, Ph.D.

Office Address:
Los Angeles, CA 90095

Associate Professor, Brain Research Institute, Microbiology, Immunology & Molecular Genetics
Member, Immunity, Microbes & Molecular Pathogenesis GPB Home Area, Neuroscience GPB Home Area
Research Interests
Our research focuses on sensory circuit function in parasitic and free-living animals, and lies at the interface of neurobiology and parasitology. Nearly all organisms respond to sensory stimuli, but how sensory circuits specify behavior is poorly understood. We are investigating the neural basis of sensory behaviors in the context of human parasitism. We use parasitic nematodes and the free-living nematode C. elegans as models. The goals of our research are to understand how parasitic worms use sensory cues to locate hosts to infect, how sensory circuits of parasitic animals differ from those of free-living animals to enable parasitic behaviors, and how sensory microcircuits generate flexible outputs. Our research addresses fundamental questions of sensory circuit function and evolution. In addition, human-parasitic worms are a major cause of morbidity worldwide, and a better understanding of their behaviors may enable the development of novel strategies for preventing infections.
Bryant AS, Ruiz F, Gang SS, Castelletto ML, Lopez JB, Hallem EA A critical role for thermosensation in host seeking by skin-penetrating nematodes. Curr Biol. 2018; 28: 2338–2347.
Banerjee N, Hallem E Sexual Dimorphisms: How sex-shared neurons generate sex-specific behaviors. Curr Biol. 2018; 28: R254-R256.
Gang SS, Castelletto ML, Bryant AS, Yang E, Mancuso N, Lopez JB, Pellegrini M, Hallem EA Targeted mutagenesis in a human-parasitic nematode. PLoS Pathog. 2017; 13: e1006675.
Guillermin ML, Carrillo MA, Hallem EA A single set of interneurons drives opposite behaviors in C. elegans. Curr Biol. 2017; 27: 2630-2639.
Ruiz F, Castelletto ML, Gang SS, Hallem EA Experience-dependent olfactory behaviors of the parasitic nematode Heligmosomoides polygyrus. PLoS Pathog. 2017; 13: e1006709.
Cevallos JA, Okubo RP, Perlman SJ, and Hallem EA Olfactory preferences of the parasitic nematode Howardula aoronymphium and its insect host Drosophila falleni. J Chem Ecol. 2017; 43: 362-373.
Park HB, Sampathkumar P, Perez CE, Lee J, Tran J, Bonanno JB, Hallem EA, Almo SC, and Crawford JM Stilbene epoxidation and detoxification in a Photorhabdus luminescens-nematode symbiosis. J Biol Chem. 2017; 292: 6680-6694.
Gang SS and Hallem EA Mechanisms of host seeking by parasitic nematodes. Mol Biochem Parasitol. 2016; 208: 23-32.
Rengarajan S and Hallem EA Olfactory circuits and behaviors of nematodes. Curr Opin Neurobiol. 2016; 41: 136-148.
Lee J, Dillman AR, Hallem EA Temperature-dependent changes in the host-seeking behaviors of parasitic nematodes. BMC Biol. 2016; 14: 36.
Carrillo MA and Hallem EA Gas sensing in nematodes. Mol Neurobiol. 2015; 51: 919-931.
Pena JM, Carrillo MA, and Hallem EA Variation in the susceptibility of Drosophila to different entomopathogenic nematodes. Infect Immun. 2015; 83: 1130-8.
Castelletto ML, Gang SS, Okubo RP, Tselikova AA, Nolan TJ, Platzer EG, Lok JB, and Hallem EA Diverse host-seeking behaviors of skin-penetrating nematodes. PLoS Pathog. 2014; 10: e1004305.
Carrillo MA, Guillermin ML, Rengarajan S, Okubo RP, and Hallem EA O2-sensing neurons control CO2 response in C. elegans. J Neurosci. 2013; 33: 9675-83.
Dillman AR, Guillermin ML, Lee J, Kim B, Sternberg PW, and Hallem EA Olfaction shapes host-parasite interactions in parasitic nematodes. Proc Natl Acad Sci USA. 2012; 109: E2324-E2333.
Chaisson KE and Hallem EA Chemosensory behaviors of parasites. Trends Parasitol. 2012; 28: 427-436.
Hallem EA, Dillman AR, Hong AV, Zhang Y, Yano JM, DeMarco SF, and Sternberg PW A sensory code for host seeking in parasitic nematodes. Curr Biol. 2011; 21: 377-83.
Guillermin ML, Castelletto ML, and Hallem EA Differentiation of carbon dioxide-sensing neurons in Caenorhabditis elegans requires the ETS-5 transcription factor. Genetics. 2011; 189: 1327-39.
Hallem EA, Spencer WC, McWhirter RD, Zeller G, Henz SR, Ratsch G, Miller DM, Horvitz HR, Sternberg PW, and Ringstad N Receptor-type guanylate cyclase is required for carbon dioxide sensation by Caenorhabditis elegans. Proc Natl Acad Sci USA. 2010; 108: 254-259.
Hallem EA and Sternberg PW Acute carbon dioxide avoidance in Caenorhabditis elegans. Proc Natl Acad Sci USA. 2008; 105: 8038-43.
Hallem EA, Rengarajan M, Ciche TA, Sternberg PW Nematodes, bacteria, and flies: a tripartite model for nematode parasitism. Curr Biol. 2007; 17: 898-904.
Hallem EA and Carlson JR Coding of odors by a receptor repertoire. Cell. 2006; 125: 143-60.
Hallem EA, Dahanukar A, and Carlson JR Insect odor and taste receptors. Ann Rev Entomol. 2006; 51: 113-35.
Dahanukar A, Hallem EA, and Carlson JR Insect chemoreception. Curr Opin Neurobiol. 2005; 15: 423-30.
Hallem EA, Fox AN, Zwiebel LJ, and Carlson JR Olfaction: mosquito receptor for human-sweat odorant. Nature. 2004; 427: 212-3.
Hallem EA, Ho MG, and Carlson JR The molecular basis of odor coding in the Drosophila antenna. Cell. 2004; 117: 965-79.
Hallem EA and Carlson JR The odor coding system of Drosophila. Trends Genet. 2004; 20: 453-9.
Hallem EA and Carlson JR The spatial code for odors is changed by conditioning. Neuron. 2004; 42: 359-61.
Shirke S, Faber SC, Hallem E, Makarenkova HP, Robinson ML, Overbeek PA, and Lang RA Misexpression of IGF-I in the mouse lens expands the transitional zone and perturbs lens polarization. Mech Dev. 2001; 101: 167-174.