People
Principle Investigator
James Dewar
James carried out his undergraduate studies at the University of Bath, England, and graduated in 2007 with First Class Honours in Molecular and Cellular Biology. He received his PhD in 2011 in yeast genetics from Newcastle University, England, before undertaking post-doctoral training in Johannes Walter’s lab at Harvard Medical School, where he became a Charles A. King Trust Fellow. In 2016, James joined the Vanderbilt Faculty as an Assistant Professor of Biochemistry. Since joining Vanderbilt, James has been a recipient of a Joe and Dorothy Brown Foundation award for research into healthy aging and is an American Cancer Society Research Scholar.
Outside of the lab, James is a devoted parent, low-key audiophile, and podcast addict.
Email: james.dewar@vanderbilt.edu
Science Twitter Handle: @JamesMDewar
Graduate students
Sabrina Van Ravenstein
Sabrina graduated The University of Texas at Austin with a Bachelors degree in Biology Honors (B.S.A.) in 2018. While studying, she worked part-time as an Undergraduate Research Assistant for Dr. Kevin Dalby under the guidance of Dr. Tamer Kaoud for 3 years. In the Dalby lab she worked on small-molecule inhibitors for MAP kinases. In 2018, Sabrina joined the Vanderbilt IGP program and then joined the Dewar Lab in April of 2019. She currently works on the mechanisms of how topoisomerases and topoisomerase-targeting drugs affect DNA replication termination.
Outside of the lab, Sabrina can be spotted browsing the local farmer’s markets, baking sourdough, or trying to min-max her D&D character.
Science Twitter Handle: @sabrinadoessci1
Emma Vontalge
Emma graduated with honors from Iowa State University in 2020 with a degree in Biochemistry. During her time at Iowa State, Emma was an undergraduate researcher in the Sashital Lab where she developed an inducible protein dimerization tool using the CRISPR-Cas protein Cas6. Emma came to Vanderbilt through the IGP program and joined the Dewar lab in May 2021.
During her free time Emma enjoys working out, spending time with friends and family, exploring Nashville, and scrapbooking!
Sara Conwell
Sara received her B.A. from Vanderbilt University in 2020, double majoring in Molecular & Cellular Biology and Medicine, Health, & Society. During her undergraduate years, Sara worked as an undergrad. researcher in Dr. Katherine Friedman’s lab where she studied mechanisms of telomere maintenance and telomerase regulation. In 2020, Sara continued her studies at Vanderbilt, entering the Vanderbilt Interdisciplinary Graduate Program (IGP). Upon completion of her first year, Sara joined the Dewar Lab where she currently studies mechanisms of replication restart.
When she is not in lab, Sara likes to spend time with family and friends, explore new areas of Nashville, and watch trashy reality tv.
Nabil Saleh
Nabil graduated from University of Tennessee – Knoxville with a Bachelor’s of Science in Chemistry. He performed computational modeling for his Undergraduate Honor’s research under Dr. Robert Hinde. Before joining the IGP at Vanderbilt, Nabil worked the lab of Ann Richmond studying immunotherapies against Melanoma and Breast Cancer. Nabil has undertaken a variety of research projects, ranging from Organometallic chemical synthesis to translational research on Uveal Melanoma / Retinoblastoma. Nabil joined the Dewar lab as a graduate student in 2023.
Outside of lab, Nabil holds positions in Vanderbilt’s student leadership including President of the Honor Council and Graduate School Representative to the Appellate Review Board.
Josh Gann
Josh graduated from University of Minnesota-Twin Cities with a degree in Chemistry (B.S) in 2023. During his time in Minneapolis, Josh was an undergraduate research assistant for Dr. Natalia Tretyakova where he helped to synthesize oligonucleotide and peptide tools to be used in mass spectrometry-based assays investigating epigenomic modifications by TET-dioxygenases and electrophile exposure in industrial settings. Josh joined the Dewar Lab in 2023 through the QCB program and is currently investigating how protein-protein and drug interactions with topoisomerase affect DNA replication.
During his free time, you can find Josh brewing beer, doing crossword puzzles, playing pickup basketball, or taking care of his cat Stella.
Research technicians
Obehi Ozua
Obehi graduated from Southwestern University with a B.S degree in Biochemistry in 2023. During her undergraduate years, she participated in a Research Experience for Undergraduates (REU) at Purdue University with the Tao Lab. Under the guidance of Dr. Tao, she worked on finding strategies to optimize their one-pot extracellular vesicle extraction method. Obehi joined the Dewar lab as a research technician in 2023.
In her free time, Obehi enjoys spending time with friends, watching movies and baking.
Steven Dahmen
Steven graduated from the University of California, Santa Cruz with a Bachelors degree in Biochemistry and Molecular Biology (B.S.) in 2020. He worked as an Undergraduate researcher for Dr. Camilla Forsberg under the guidance of Donna Poscablo for 1 and a half years. In the Forsberg Lab, Steven worked on characterizing a novel population of age-specific platelets in mice. In September of 2020, Steven joined the Zinkel lab at Vanderbilt University as a Research Assistant 1. Steven subsequently joined the Dewar lab for his Masters research, and then stayed on as a Research Assistant after obtaining his Masters in Biochemistry in 2024.
During his free time, Steven likes to play video games, play with his dog Sox, or enjoy the outdoors looking for new ant queens.
Lab Alumni
| Name | Position in lab | Grad Year | Current Position |
| Darren Heintzman | Research Assistant | 2019 | PhD Candidate, Vanderbilt University Medical Center |
| Lillian Campos | Post-doc | 2022 | Biotech |
| Tamar Kavlashvili | Graduate student | 2023 | Post-doc, Sloan Kettering Institute |
| Stedman Stephens | Research Assistant | 2023 | PhD Student, Vanderbilt University |