Labor Mural by Judy Taylor Labor Mural by Judy Taylor

Tewhey Lab Members

John Butts
John Butts
Graduate Student
john.butts (at)

John graduated from University of Dayton with a B.S./M.S. in Biology. It was there he first began his interest in gene regulation, particularly cis-regulatory elements, while working with Dr. Thomas Williams studying the evolution of pigmenation patterns in Drosophila. Following graduation John joined Dr. Victoria Meller’s lab at Wayne State University working as Lab Manager and Research Assistant studying the impact of chromatin conformation on dosage compensation in fruit flies. As a PhD student John hopes to continue to probe the logic underyling CREs and how advancements in experimental methods can enhance this study. In his free time John enjoys making music, running, and playing tennis.

Rodrigo Castro
Rodrigo Castro
Associate Computational Scientist
rodrigo.castro (at)

Rodrigo graduated from Georgia State University with a doctoral degree in mathematics, focusing in deep learning research. As a computational scientist in the Tewhey lab, Rodrigo works on generative deep-learning models for cis-regulatory elements and deriving new synthetic elements for desired regulatory functions. In his spare time, Rodrigo enjoys practicing music, biking, and learning about new AI advances.

Hannah Dewey
Hannah Dewey
Data Analyst I
hannah.dewey (at)

Hannah graduated from the University of Maine with a degree in Mathematics, while working with Dr. Andre Khalil in the CompuMAINE lab. Before joining the Tewhey Lab, Hannah completed postgraduate degrees in Applied Mathematics (2015) and Bioinformatics and Computational Genomics (2019) at Rensselaer Polytechinic Institute and Queens University Belfast respectively, as well as serving as a Peace Corps Volunteer in Namibia. Now, as a data analyst in the Tewhey Lab, Hannah works developing pipelines to be used in the analysis of MPRA count data as well as participating in the analysis itself. In her free time Hannah enjoys baking, sharing said baked goods with other lab members, and knitting.

Debi Foster
Debi Foster
Research Administrative Asisstant
debi.foster (at)

Before joining JAX, Debi has 20 years of Admin experience primarily in the medical field. As the RAA for the Tewhey Lab, Debi assists them with ordering products for the lab, coordinating travel and expenses for conferences and scheduling meetings as necessary. In her spare time Debi likes to spend time with her family, go boating in the ocean and be outside playing catch with the dogs.

Susan Kales
Susan Kales
Associate Lab Manager
susan.kales (at)

Susan graduated from the University of Colorado, Boulder with a degree in Molecular Cellular Developmental Biology. Before joining JAX for four years Susan worked at Merck & Co. as a Research Biologist. Susan worked for six years in Tom Jessell’s lab and during that time held a dual position for four years in the Jessell and Axel labs at Columbia University. Susan was there when Dr. Axel won the Nobel Prize. Prior to working at Columbia University, Susan worked at MSKCC in Manhattan in a molecular diagnostic lab and she worked at Chugai Pharmaceutical Co. in Tokyo, Japan in the International Group. Susan is a Research Assistant in the Tewhey Lab and contributes to many different projects but her expertise is in ES cell work. In her spare time Susan likes to paint, draw, walk/hike with her dog and husband, cook and be on the water boating or swimming.

Kousuke Mouri (KOH-skay)
Kousuke Mouri (KOH-skay)
Research Scientist
kousuke.Mouri (at)

Kousuke graduated from Kyoto University with a degree in life science, while working with Dr. Tadashi Uemura by using six-legged fruit fly. Before coming to Jax, Kousuke had been working with four-legged mouse as a postdoctoral fellow with Dr. Toshihiko Shiroishi at National Institute of Genetics, Japan. Now, as a postodoctoral associate in the Tewhey lab, Kousuke works 2-legged human genetics to decipher the mechanisms of the cis regulatory element which makes wonderful variety of animal morphology and phenotype. In his free time Kousuke enjoys snowboarding and taking care of his kawaii tortoise, Chicago.

Niketa Nerurkar
Niketa Nerurkar
Graduate Student
niketa.nerurkar (at)

Niketa graduated from Christ University, Bangalore with a triple major B.S. in Biotechnology, Chemistry and Zoology. Following graduation, Niketa joined Dr. Sangeeta Bhatia’s lab at MIT working as a research technician and assistant lab manager, studying liver-stage malaria and consequently,circadian patterns of drug metabolism and immune response in the liver. Now, as a graduate student in the Tewhey lab, Niketa aims to study howregulatory variants contribute to complex disease. In her free time, Niketaenjoys long walks, swimming, reading, exploring new restaurants and jamming to Taylor Swift and 2000-2010’s pop music.

Ryan Tewhey
Ryan Tewhey
Principal Investigator
ryan.tewhey (at)

Ryan is a human geneticist with expertise in developing large-scale screening methods to understand how genetic variation impacts human traits and disease. His primary research focus is the investigation of non-coding regions of the genome that control gene expression. He has pioneered the use of massively parallel reporter assays (MPRA) and CRISPR based screens of non-coding regions to identify causal alleles from genome wide association studies. His broad interests lie in the application of novel technologies to answer questions related to human health and disease. Ryan completed his undergraduate degree at the University of Maine, Orono. He received his PhD from the University of California, San Diego in 2012 while carrying out work at The Scripps Research Translational Institute and completed his postdoctoral work at Harvard University and The Broad Institute. His awards include Forbes Magazine’s 30 under 30, NSF/A-STAR EAPSI fellow, the Charles J. Epstein Award for Research Excellence by the American Society of Human Genetics, an NIH Pathway to Independence Award, Maine Public Health Association Champion Award, and the NHGRI Genomic Innovator Award. Ryan is currently an associate professor at The Jackson Laboratory in Bar Harbor and holds appointments at Tufts University School of Medicine and The University of Maine Graduate School of Biomedical Science and Engineering.

Tewhey Lab Alumni

Lucy Benjamin - Research Administrative Assistant
2017 - 2022  

Daniel Berenzy - Research Assistant I
2019 - 2022   Subsequent Position: Cell and Molecular Biology Technician (Molecular Biology Services - JAX)

Natalia Fuentes - Summer Student
2018 - 2022   Subsequent Position: Graduated - Harvard

Connor Kean - Summer Student
2017 - 2019   Subsequent Position: Graduate Student - Cornell

Frank Liu - Summer Student
2022 - 2022   Subsequent Position: Undergraduate - Harvard

Luke Parsley - Graduate Student
2019 - 2022   Subsequent Position: Research Associate - Armed Forces Radiobiology Research Institute