Steven Jacobsen, PhD

Steven Jacobsen, Ph.D. 



Steven Jacobsen, PhD, focuses on the area of epigenetics, and particularly on the question of how genetically identical cells are able to inherit alternative states of gene activity without alterations in the primary sequence of the DNA. Epigenetics involves stable and inherited chemical modifications of chromatin; the combination of DNA and other proteins that make up chromosomes. The most common epigenetic modification is methylation of the DNA.

In his research, Dr. Jacobsen uses Arabidopsis thaliana, a small flowering plant native to Europe, Asia and northwestern Africa, as a model system to study how chromatin modifications silence certain genes. He also conducts studies in other systems, such as human embryonic stem cells. Using genetics and biochemistry, Dr. Jacobsen seeks to understand the mechanisms that control DNA methylation. Proper DNA methylation of particular genes is critical for normal development and cellular differentiation of most organisms, including humans. Dr. Jacobsen co-directs the Broad Stem Cell Research Center DNA Sequencing – Bioinformatics Core Resource with Matteo Pellegrini, PhD.

Dr. Jacobsen expanded into stem cell research because stem cells provide good model systems for studying DNA methylation. Stem cells are tolerant to dramatic loses of DNA methylation, allowing for detailed study of the methylation processes. Dr. Jacobsen hopes his research into DNA methylation will help in the use of stem cells for regenerative medicine. DNA methylation controls gene expression, which helps to maintain the stem cell’s ability to develop into any cell in the body. It also is critical for stem cell differentiation.

In addition to his affiliation with the Broad Stem Cell Research Center at UCLA, Dr. Jacobsen is a member of UCLA’s Jonsson Comprehensive Cancer Center and the cancer center’s Gene Regulation Program Area. He also is an investigator with the Howard Hughes Medical Institute and a fellow of the American Association for the Advancement of Science.

A professor of molecular, cell and development biology in the Life Sciences, Dr. Jacobsen came to UCLA from the California Institute of Technology in 1998. He earned his bachelor’s degree in biology from California Polytechnic State University San Luis Obispo and his doctoral degree from the University of Minnesota.

Dr Jacobsen’s work is funded by the National Science Foundation’s plant genome research program, the National Institutes of Health and the Howard Hughes Medical Institute.