![]() ![]() Today’s high-throughput genome sequencers actually work best on DNA measuring scores to hundreds of nucleotides-the iconic A’s, T’s, C’s, and G’sthat comprise DNA - long. It’s almost always as badly fragmented as a shattered wine goblet because “DNA decay begins within days of death,” said UCSC’s Shapiro. Scientists collect tissue samples from museum specimens: the Museums Victoria in Melbourne, Australia, had great Tasmanian tigers, for instance, while the Royal Ontario Museum in Toronto had a nice toe bone from the little bush moa. ![]() Last month, researchers in Australia unveiled the genome of the Tasmanian tiger, the last of which died in captivity in 1936. Scientists are also close to reconstructing the genomes of the dodo, the flightless bird that went extinct from Mauritius, its only home, in the late 1600s and the great auk, which lived in the North Atlantic before dying out in the mid-19th century. The zebra-like quagga was the first extinct species to have its DNA sequenced, back in the genomic Stone Age of 1984, but it’s not up to modern standards. The nearly complete extinct genomes include two human relatives, Neanderthals and Denisovans, in addition to the woolly mammoth, and the passenger pigeon. “The number that’s actually been done is possibly quadruple” the four or five extinct genomes formally reported, “but the results are just sitting in people’s labs.” Journals demand more from papers than “here it is,” said Ben Novak, a co-author of the passenger pigeon study. That the assembly of an extinct genome is being spread like scientific samizdat is not unusual in this field. Morten Erik Allentoft of the Natural History Museum of Denmark, an expert on moa DNA and other extinct genomes, called it “a significant step forward.” Beth Shapiro of the University of California, Santa Cruz, who led a 2017 study reconstructing the genome of the passenger pigeon, called it “super cool” because it “gives us an extinct genome on an evolutionary branch where we hadn’t had any before.” The work on the little bush moa has yet to be published in a journal (the researchers posted a non-peer-reviewed paper on a public site), but colleagues in the small world of extinct genomes sang its praises. “De-extinction probability increases with every improvement in ancient DNA analysis,” said Stewart Brand, co-founder of the nonprofit conservation group Revive and Restore, which aims to resurrect vanished species including the passenger pigeon and the woolly mammoth, whose genomes have already been mostly pieced together.įor the moa, whose DNA was reconstructed from the toe bone of a museum specimen, that might require a little more genetic tinkering and a lot of egg: The 6-inch long, 1-pounder that emus lay might be just the ticket. The achievement moves the field of extinct genomes closer to the goal of “de-extinction”-bringing vanished species back to life by slipping the genome into the egg of a living species, “Jurassic Park”-like. Scientists at Harvard University have assembled the first nearly complete genome of the little bush moa, a flightless bird that went extinct soon after Polynesians settled New Zealand in the late 13th century. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |