Biologists Construct a “Periodic Table” for Cell Nuclei – And Discover Something Strange, Baffling and Unexpected
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The two teams met at a conference in the Austrian mountains, where Rowland presented his lab’s latest work. They soon realized that Hoencamp had hit on a way to convert human cells from one nuclear type to another.
“When we looked at the genomes being studied at the DNA Zoo, we discovered that evolution had already done our experiment many, many times! When mutations in a species break condensin II, they usually flip the whole architecture of the nucleus,” said Rowland, senior author on the study. “It’s always a little disappointing to get scooped on an experiment, but evolution had a very long head start.”
The team decided to work together to confirm condensin II’s role. But then the COVID-19 pandemic struck, and much of the world shut down.
“Without access to our laboratories, we were left with only one way to establish what condensin II was doing,” Hoencamp said. “We needed to create a computer program that could simulate the effects of condensin II on the chain of hundreds of millions of genetic letters that comprise each human chromosome.”
The team turned to José Onuchic, the Harry C. and Olga K. Wiess Chair of Physics at Rice. “Our simulations showed that by destroying condensin II, you could make a human nucleus reorganize to resemble a fly nucleus,” said Onuchic, co-director of CTBP, which includes collaborators at Rice, Baylor, Northeastern University and other institutions in Houston and Boston.
(A caption under the picture with the "evolution of man" into the fly says-An artist’s interpretation of evolution from primates, via modern humans to mosquitoes. This artwork is a play on data gathered by biologists at Baylor College of Medicine, the Netherlands Cancer Institute and Rice University that shows the organization of the human genome can change into something that resembles the genome organization of mosquitoes. Credit: Joris Koster/Netherlands Cancer Institute)