{"id":130646,"date":"2024-07-12T08:08:00","date_gmt":"2024-07-12T12:08:00","guid":{"rendered":"http:\/\/kendallharmon.net\/?p=130646"},"modified":"2024-07-12T17:32:16","modified_gmt":"2024-07-12T21:32:16","slug":"nyt-a-mammoth-first-52000-year-old-dna-in-3-d","status":"publish","type":"post","link":"https:\/\/kendallharmon.net\/?p=130646","title":{"rendered":"(NYT) A Mammoth First: 52,000-Year-Old DNA, in 3-D"},"content":{"rendered":"\n

In 2018 an international team of scientists \u2014 from labs in Houston, Copenhagen, Barcelona and beyond \u2014 got their hands on a remarkable biological specimen: a skin sample from a 52,000-year-old woolly mammoth that had been recovered from the permafrost in Siberia. They probed the sample with an innovative experimental technique that revealed the three-dimensional architecture of the mammoth\u2019s genome. The resulting paper<\/a> was published on Thursday in the journal Cell.<\/p>\n\n\n\n

Hendrik Poinar, an evolutionary geneticist at McMaster University in Canada, was \u201cfloored\u201d \u2014 the technique had successfully captured the original geometry of long stretches of DNA, a feat never before accomplished with an ancient DNA sample. \u201cIt\u2019s absolutely beautiful,\u201d said Dr. Poinar, who reviewed the paper for the journal.<\/p>\n\n\n\n

The typical method for extracting ancient DNA from fossils, Dr. Poinar said, is still \u201ckind of cave man.\u201d It produces short fragments of code composed of a four-letter molecular alphabet: A (adenine), G (guanine), C (cytosine), T (thymine). An organism\u2019s full genome resides in cell nuclei, in long, unfragmented DNA strands called chromosomes. And, vitally, the genome is three-dimensional; as it dynamically folds with fractal complexity, its looping<\/a> points of contact help dictate gene activity.<\/p>\n\n\n\n

\u201cTo have the actual architectural structure of the genome, which suggests gene expression patterns, that\u2019s a whole other level,\u201d Dr. Poinar said.<\/p>\n\n\n\n

Read it all<\/a>.<\/p>

My latest for @Nature<\/a>: On Siberia's frozen tundra some 50,000 years ago, a woolly mammoth met its end. In the animal\u2019s skin, researchers have now discovered chromosomes preserved in their original 3D shape\u2014a feat previously thought impossible https:\/\/t.co\/zr1mvj10h7<\/a><\/p>— Giorgia Guglielmi (she\/her) (@GiorgiaWithAnI) July 11, 2024<\/a><\/blockquote>