Scientists at the University of Massachusetts Amherst are pioneering a monumental research project, diving into the cerebral depths of primates to unravel the mysteries tying gene expression to brain evolution. A substantial study spearheaded by UMass Amherst biologists has sequenced the RNA from 18 different primate species - encompassing the broadest spectrum to date. This initiative may hold the key to understanding complex brain functions and potentially shed light on human neurodegenerative diseases such as Alzheimer's.
The endeavor, reflecting meticulous effort, required obtaining samples of brain tissue from a range of primates – including humans. The study set out to distinctly map the 17,000 genes expressed in primate brains, a task of staggering proportions. Lead author Katie Rickelton, a doctoral candidate, highlighted the essence of the project: "Primates, and especially humans, are defined by having very large brains compared to their body size—and yet, humans, chimpanzees, and lemurs are all very different, despite having similar DNA sequences," she told UMass News. The team believes that gene expression levels may partly clarify these differences.
Earlier studies scrutinizing RNA in primate brains didn't cast as wide a net, focusing on a limited selection of species. "If we are going to figure out what makes humans unique among primates," stated Courtney Babbitt, associate professor of biology and senior author on the paper, "we’re going to have to study a wider selection of primates, and no one has looked at such a large sample before." The team's research was published in the renowned journal eLife, according to UMass News.
By collaborating with revered institutions like the National Institute for Child Health and Human Development Brain and Tissue Bank for Developmental Disorders and the National Chimpanzee Brain Resource, the team was able to ethically source high-quality brain tissue samples. Their findings revealed a remarkable level of variation across the primate species, specifically in humans and chimpanzees. This suggests that even short evolutionary timelines can birth significant changes in brain structure and function. In an interesting revelation, the cerebellum displayed the highest level of evolutionary-driven differentiation. "It’s evolutionarily the oldest part of the brain," Rickelton explained, "and so has had the most time to evolve in different ways for each of the species."
With their newfound insights, the work of Rickelton, Babbitt, and their colleagues not only opens a window to our humanity but also prepares them to further investigate specific genes that could enlighten our understanding of primate brain nuances. Moreover, their research could pave the way for breakthroughs in the battle against degenerative brain conditions. "It’s one of the great evolutionary paradoxes: humans and chimps have pretty much the same genes, and yet we’re so different," remarked Babbitt in UMass News. Their findings are the outcome of generous funding by various institutions, including the U.S. National Science Foundation and the National Institutes of Health.
