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https://www.nytimes.com/2024/05/31/science/largest-genome-fern-plant.html?u2g=c&unlocked_article_code=1.xU0.yeWV.9F3qa_6Df7-g&smid=url-share>
"Last year, Jaume Pellicer led a team of fellow scientists into a forest on
Grande Terre, an island east of Australia. They were in search of a fern called
Tmesipteris oblanceolata. Standing just a few inches tall, it was not easy to
find on the forest floor.
“It doesn’t catch the eye,” said Dr. Pellicer, who works at the Botanical
Institute of Barcelona in Spain. “You would probably step on it and not even
realize it.”
The scientists eventually managed to spot the nondescript fern. When Dr.
Pellicer and his colleagues studied it in the lab, they discovered it held an
extraordinary secret.
Tmesipteris oblanceolata has the largest known genome
on Earth. As the researchers described in a study published on Friday, the
fern’s cells contain more than 50 times as much DNA as ours do.
If you find it strange that such a humble plant has such a gigantic genome,
scientists do, too. The enigma emerged in the 1950s, when biologists discovered
that the double helix of DNA encodes genes. Each gene consists of a series of
genetic letters, and our cells read those letters to make corresponding
proteins.
Scientists assumed that humans and other complex species must make a lot of
different proteins and therefore have bigger genomes. But when they weighed the
DNA in different animals, they discovered they were wildly wrong. Frogs,
salamanders and lungfish had far bigger genomes than humans did.
It turns out that genomes are much weirder than scientists had expected. We
carry about 20,000 protein-coding genes, for example, but they make up only 1.5
percent of the 3 billion pairs of letters in our genome.
Another nine percent or so is made up of stretches of DNA that don’t encode
proteins but still carry out important jobs. Some of them, for example, act
like switches to turn neighboring genes on and off.
The other 90 percent of the human genome has no known function. Some scientists
have an affectionate nickname for this vast quantity of mysterious DNA: junk."
Via
Fix the News:
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https://fixthenews.com/good-news-water-sanitation-hygiene-poverty-cambodia-barn-owls-uk/>
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
