Dr. john gearhart is a leading scientist in human genetics and an advocate for embryonic stem cell research. His numerous accolades include an induction in 1999 into the Academy of Achievement, a nonprofit museum of living history located in Washington, D.C. Gearhart works on stem cells derived from fetal tissue yet actively supports federal funding for embryonic stem cells. His chief argument in favor of using fetal tissue from abortion clinics is that this tissue would be discarded otherwise. At present, when he obtains tissue for research, there is no contact between the donating woman, who has signed a consent form, and the researchers. The woman is not financially rewarded in any way, nor is anyone involved in the transfer process.
Gearhart grew up in Girard College, an orphanage in Philadelphia, Pennsylvania, which he entered at the age of 6 years and left between the ages of 16 and 17 years. His father had died in a car accident, and his mother consequently placed John and one of his brothers into the all-male orphanage, which had been established in 1848 to raise and educate boys. Gearhart lived at the orphanage until he moved to Pennsylvania State University after graduation.
Although initially intending to study horticulture, Gearhart quickly developed a passion for human genetics. His first goal was to be a pommologist—an expert in growing apples, peaches, and pears. At the time, the way to improve on these fruits was through breeding. Unsatisfied with the time commitment dedicated to one fruit tree, Gearhart turned to flowers, which could show the results of selective breeding much more rapidly.
It did not take long for Gearhart’s attentions to turn to animal genetics. He wanted to study humans, but the resources were not available in those years; therefore, he started with the fruit fly and continued with the mouse until he reached Johns Hopkins University School of Medicine, where he could finally study human genetics. In the field of human genetics, a significant portion of Gearhart’s work has been on the cellular and molecular mechanisms of the genetic mutation causing Down syndrome (trisomy 21).
Gearhart first attended Pennsylvania State University, earning a bachelor’s of science in biological science in 1964. From there, Gearhart moved to the University of New Hampshire (UNH) to obtain a master’s degree in genetics in 1966. At UNH, Gearhart became a self-proclaimed expert on lilacs, as New Hampshire is “the lilac state.”
From UNH, Gearhart moved to a leading genetics institute: Cornell University in Ithaca, New York. At Cornell, in 1970, Gearhart earned his doctoral degree in genetics, development, and embryology. He then held positions at the Institute for Cancer Research in Philadelphia and the University of Maryland in Baltimore before settling down at Hopkins in 1980. Ten years later, Gear-hart joined the Medical Genetics Center in addition to the Center for Reproductive Biology.
At Hopkins, Gearhart has served as professor of comparative medicine, gynecology and obstetrics, physiology, and population dynamics on the medical campus, as well as at the Bloomberg School of Public Health, where he is professor of biochemistry and molecular biology. As of early 2008, he serves in the department of gynecology and obstetrics as director of research and director of the developmental genetics division.
Much of his research has focused on the manner in which genes regulate the formation of tissues and embryos. For over 20 years, he has researched the causes of mental retardation and other birth defects. The isolation of the stem cells of mice enabled him to attack a difficult challenge, the isolation and culturing of human stem cells.
Gearhart, working with his team, was the first scientist to isolate human pluripotent stem cells in 1998, retrieving his stem cells from the developing gonads of aborted fetuses. During his research, Gearhart’s team successfully identified and isolated the stem cells and maintained them in a nutritive environment where they continued reproducing without differentiating. These cells were characterized to be similar to embryonic germ cells derived from the gonadal ridge and to embryonic stem cells derived from the inner cell mass. The achievement may profoundly impact drug development and transplant therapy, and supports the possibility of growing human tissues in the laboratory to replenish failing organs. The stem cells that Gearhart uses are pluripotent, meaning they have the ability to differentiate into multiple cell types; however, and importantly, they are not totipotent, which would mean that they have the ability to differentiate into a living, independent organism.
Gearhart has been an advocate of federal funding for further embryonic stem cell research. He believes that the possible future benefits of human stem cell research warrant the support of the national government.
