It's no secret that we humans tend to carry a little more pads on our bones than our closest relatives. Even without a diet of donuts and Netflix, evolution has left us with bodies that accumulate fat.
The analysis of fatty tissues from different primates found that part of it can be reduced to subtle differences in the way cells pack DNA, making it difficult to make our spare tire the type of fat that burns easily. Biologists at Duke University have discovered that, unlike chimpanzees and macaques, we humans do not have easy access to calorie-generating sets of genes in our fat cells. As a result, the rich supply of lipids hidden in our fat tissue remains in force unless we work extraordinarily to burn them.
This is not a recent phenomenon imposed by the lifestyle of the couch. While other primates tend to have less than 9% body fat in the wild, healthy people can easily carry up to twice that amount.
"We are fat maies," says Devi Swain-Lenz, a research fellow in the Function Group.
Such a significant metabolic difference is made even more curious, given that the random sequence of human and chimpanzee DNA differs by only a few percent.
To learn how small differences in coding can be large Unlike the waist, Swain-Lenz and her team have taken fat samples from chimpanzee fat, humans and a more distant kernel rhizome. In fact, there are two types of fat that you need to know: brown and white. Brown fat stores fat in small droplets, surrounded by energy-converting mitochondria. Its primary goal is to quickly generate heat when the temperature falls by feeding trembling muscles. Meanwhile, white fat stubbornly sticks to its reserves, providing not only backup fuel but acts as a physical layer of protection and thermal insulation. This is the tissue that expands in the time of abundance and the type of fat that researchers are most interested in. "Long DNA strands are usually wound safely inside cells wrapped around proteins, their exposed segments are easy to access templates that amplify and promote sequences
These so-called open chromatin regions are significantly different between humans and the other two In fact, just under 3,000 regions were either easier or more difficult to access for humans than chimpanzees, a way of lipid metabolism.
One of these buried sequences, a transcription factor called nuclear fact or 1
The size of the brain As our three-dimensional chimpanzee brains barely rumble, the energy needs of the larger nervous system are significant, so it makes sense for our bodies to provide extra security in our energy supplies in the form of a big white fat.
However, just because we have survived our genes, "Maybe we could understand a group of genes that we have to turn on or off, but we're still a long way from that," he says. Swain-Lenz.
"I do not think it's as simple as flipping the key, and if so, we would have known that a long time ago."
This study is published in Biology of Genome and Evolution .