Month: September 2022

THE DEFENSE. "In an effort to prove the veracity of his discovery, Dr. Stanley redissolved and recrystallized his protein 15 times, after which point it still produced tobacco mosaic virus as powerful as the original sample. The chemical weight of the crystal substance — 17 million times greater than that of the heaviest known protein — gave Dr. Stanley the first clue as to the virus's inherent contradiction." https://lnkd.in/eSUZzUv View in LinkedIn

CELL PARTS LATER CRYSTALLIZED. "Molecular biologists went on to crystallize most of the essential components of cells and are today accustomed to thinking about cellular constituents—for example, ribosomes, mitochondria, membranes, DNA and proteins—as either chemical machinery or the stuff that the machinery uses or produces." https://lnkd.in/e3cWiQ8 View in LinkedIn

CRYSTALLIZATION AND RECONSTITUTION of a seemingly living entity is absolutely confounding to most scientists. This is the domain of the chemistry lab, retorts and Bunsen burners, not the domain of wriggling, wet, and ingenious biology. Cryopreservation of animal cells is one thing, using special reagents to avoid ice crystal formation. Crystallization is quite another. View in LinkedIn

34,000-YO VIRUS RESURRECTED from permafrost. Frozen without special reagents and slow cooling. https://lnkd.in/ekHnSGM View in LinkedIn

CRYSTALLIZATION OF VIRUSES. "Recall that many serious biologists and chemists in those earlier years still adhered to the belief that some “vital” force outside the known laws of chemistry and physics would be needed to explain the phenomenon of life." The 1946 Nobel Prize was awarded to Wendel Stanley for crystallizing tobacco mosaic virus. https://lnkd.in/eqSfd3G View in LinkedIn

WM STANLEY. "Needless to say, for a time there was great skepticism that the crystalline material could be tobacco mosaic, due chiefly to the old idea that viruses were living organisms. A wide variety of experimental approaches has been used to test the proposal that the crystalline ma-" "terial represented tobacco mosaic virus. It was found that essentially all of the virus activity present in infectious juice could be isolated in the form of the crystalline material. The virus activity of this material was about 500 times that of the starting material." (Nobel Lecture, December 12, 1946). https://lnkd.in/eRJ7Biu View in LinkedIn

FRAGMENT FROM NATURE continues on the second weekend of reductive evolution. Examples of genetic streamlining are numerous. Reductive evolution is considered to be the dominant force in evolution, interspersed by periods of explosive complexification, when new species emerge. It runs against the long-held assumption that increasing genetic complexity is the inevitable and singular driver in living things. View in LinkedIn

OBLIGATE PARASITES. "It has been well known for decades that the evolution of numerous parasitic and symbiotic organisms entails simplification rather than complexification. In particular, bacteria that evolve from free-living forms to obligate intracellular parasites can lose up to 95% of their gene repertoires without compromising the ancestral set of highly conserved genes involved in core cellular function." https://lnkd.in/egqWFZp View in LinkedIn

SPECIALIZED LIFESTYLE. "Intracellular bacteria commonly have a reduced genome size, as a consequence of their nutritional dependence on, and adaptation to their host environment and specialization." https://lnkd.in/ebgdSj3 View in LinkedIn

COMMON BACTERIAL REDUCTION. "Reductive genomic evolution, driven by genetic drift, is common in endosymbiotic bacteria." https://lnkd.in/e9TnyEE View in LinkedIn