Chromosomes have extra mystery mass
Using one of the UK’s most powerful X-ray beams, researchers recently measured the mass of the 46 human chromosomes. Results were surprising: each chromosome was about 20 times heavier than the DNA contained inside, a much greater mass than the researchers anticipated. “Our measurement suggests the 46 chromosomes in each of our cells weigh 242 picograms [trillionths of a gram],” Ian Robinson, a professor of physics at University College London, said. “This is heavier than we would expect, and if replicated points to unexplained excess mass in chromosomes.”
Each human cell normally contains 23 pairs of chromosomes. Within each chromosome is one DNA molecule and a plethora of proteins that serve a variety of functions, like compressing your two-metre strands of DNA into tiny bundles small enough to fit into individual cells.
The US government-run Human Genome Project revealed, among other things, the mass of DNA molecules. However, the weight of the chromosomes that house these molecules remained a mystery.
Understanding this could lead to further insights about the complex structure of chromosomes, which are studied extensively by medical labs for things like cancer diagnoses. The fact chromosomes weigh 20 times more than the DNA within them puzzled the team, and so far there’s no good explanation. More research is definitely needed. BRANDON SPECKTOR