Immune complexity: isolating specific DNA info read (Introduction)

by David Turell , Thursday, June 03, 2021, 00:04 (1057 days ago) @ David Turell

DNA is like a huge library with many shelved areas containing exactly precise narrow regions of specific instructions must be reviewed while not using any other shelves/regions:

https://www.sciencedaily.com/releases/2021/06/210602153352.htm

"The organization of the human genome relies on physics of different states of matter -- such as liquid and solid -- a team of scientists has discovered. The findings, which reveal how the physical nature of the genome changes as cells transform to serve specific functions,

"The genome is the library of genetic information essential for life. Each cell contains the entire library, yet it uses only part of this information. Special types of cells, such as a white blood cell or a neuron, have only certain "books" open -- those containing information relevant for their function. Researchers have long sought to determine how the genome manages these enormous libraries and allows access to the "books" that are needed, while storing away the ones not in use.

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'"We found that the parts of the genome that are being used are liquid, while the unused parts form solid-like islands," explains Alexandra Zidovska, an assistant professor in New York University's Department of Physics and the senior author of the study. "These solid-like islands serve as library bookshelves storing the books with genes not currently in use, while the liquid genome part acts like an 'open book,' which is readily accessible and used for a cell's life and function."

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"Here they found that stem cells keep their genome "open" -- making it as accessible as an open book, with "genetic pages" being easily reachable.

However, the mapping also showed that once a stem cell becomes a specialized cell, e.g. a neuron, this specialized cell keeps readily accessible only parts of the genome that are needed for its specific function. It puts away the unused parts of the genome on "bookshelves." This leaves more space for information that is being actively read out and processed.

"'These motions tell us exactly how accessible the genome is in a given place in the cell nucleus," explains Zidovska. "Moreover, these motions reveal the physical state of different parts of the genome, with liquid parts corresponding to loosely packed DNA, and solid-like parts corresponding to tightly packed DNA gels. The genome packing in these different states of matter directly impacts the genome's accessibility; the liquid parts are accessible, in contrast to the solid-like parts. The amazing thing is that this organization relies on physics of different states of matter, liquid and solid."

"'Measuring motions of distinct parts of the genome allowed us to show these different physical properties of different parts of the genome, and thus understand the genome organization -- the cell's 'library system,' " she adds.

"A proper cellular filing system is vital for human health, the researchers note.

"'Considering the vast number of cell types in the human body, if a book is missing or misplaced in this cellular library, it may lead to missing or unnecessary information, possibly leading to developmental and inherited disorders as well as afflictions such as cancer," explains Zidovska. "Therefore, revealing how the genome is organized inside the cell nucleus is critical to our understanding of these conditions and diseases. Moreover, such knowledge may help us in designing future therapies and diagnostics of such disorders.'"

Comment: Having liquid and more solid phases to pinpoint usable areas in DNA is an extremely clever clever design, as cells in general do this in multiple ways making wall-less organelles in the body of the cell by liquid or solid phase transitions isolating manufacturing processes to very specific regions. To twist an old saying 'cleverless is equal to Godliness'.