As a kid, Jesse Dixon often listened to his parents at the dinner table discussing how to run experiments and their own research laboratories. His father Jack is an internationally renowned biochemist and the former vice president and chief scientific officer of the Howard Hughes Medical Institute. His mother Claudia Kent Dixon, now retired, did groundbreaking work in the study of lipid molecules that serve as the building blocks of cell membranes.
So, when Jesse Dixon set out to pursue a career, he followed in his parents’ footsteps and chose science. But Dixon, a researcher at the Salk Institute, La Jolla, CA, has charted a different research path by studying genomics, with a focus on understanding chromosomal structure. Dixon has now received a 2016 NIH Director’s Early Independence Award to study the three-dimensional organization of the genome, and how changes in its structure might contribute to diseases such as cancer or even to physical differences among people.
“The Thinker” by Auguste Rodin (photo by Brian Hillegas)
Humans’ most unique traits, such as speaking and abstract thinking, are rooted in the outer layer of our brains called the cerebral cortex. This convoluted sheet of grey matter is found in all mammals, but it is much larger and far more complex in Homo sapiens than in any other species. The cortex comprises nearly 80 percent of our brain mass, with some 16 billion neurons packed into more than 50 distinct, meticulously organized regions.
In an effort to explore the evolution of the human cortex, many researchers have looked to changes in the portion of the genome that codes for proteins. But a new paper, published in the journal Science , shows that protein-coding DNA provides only part of the answer. The new findings reveal that an even more critical component may be changes in the DNA sequences that regulate the activity of these genes.