Dark Matter in your Chromosomes? By Brian Simpson

To my limited understanding, there is a cosmological problem, as the universe, according to the General Theory of Relativity, has more mass than it should. This has led to the postulation of Dark Matter to account for his, but as yet there is no evidence of it. The possibility that the sacred cow of physics, General Relativity, could be wrong, is a last-ditch matter, so to speak.

Anyway, something like this problem is occurring in genetics, with the mass of the 46 human chromosomes weighing more than the DNA in them. This is not trivial, as chromosomes weigh 20 times more than the DNA in them! If this is correct, chromosomes are not solely DNA, but what else are they? And, how come nobody ever noticed any “dark matter” equivalent there? It is a bit of a mystery, and I will keep an eye on what they uncover. I suspect that received genetics could be in for a surprise, if the weight experiments are confirmed.

https://www.livescience.com/human-chromosome-weight-calculated-xray.html

“How much do you weigh? No, not your body weight (we're not here to judge) — but the weight of your chromosomes, those X-shaped bundles of genetic instructions that make you you?

If you don't know offhand, then scientists have you covered. Using one of the U.K.'s most powerful X-ray beams, a team of researchers recently measured the mass of the 46 human chromosomes.

The results were surprising: Each chromosome was about 20 times heavier than the DNA contained inside them — a much greater mass than the researchers anticipated, according to their study published March 31 in the journal Chromosome Research.

"Our measurement suggests the 46 chromosomes in each of our cells weigh 242 picograms (trillionths of a gram)," study co-author Ian Robinson, a professor of physics at University College, London, said in a statement. "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, such as compressing your 6.5-foot-long (2 meters) strands of DNA into teensy bundles small enough to fit into individual cells.

The U.S. 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, according to the researchers.

To calculate the mass of a standard set of 46 human chromosomes, the study authors used a technique called X-ray ptychography — essentially, creating a 3D model of the chromosomes by shooting them with an extremely powerful X-ray beam at the U.K.'s Diamond Light Source science center in Oxfordshire. With this model, the researchers could calculate the precise number of electrons in each chromosome, allowing the researchers to estimate the chromosomes'  total mass.

The fact that chromosomes weigh 20 times more than the DNA within them puzzled the team; so far, there's no good explanation for this "excess" mass, but further study could reveal the secrets buried below the X.”