The award for the longest animal genome now goes to a South American fish. At 91 billion base pairs, that's double the previous record… and 30 times the human genome.
Yet it is present in every cell of this creature called the lungfish.The Lipidose Paradox) Because it has the ability to breathe outside the water.
The previous record, of “only” 43 billion base pairs, was also held by a lungfish, but from Australia. The team of researchers who Published August 14 in the magazine natureHe has now decoded the genomes of six species of lungfish, all of which have abnormally large genomes.
This ability to breathe air gives them an advantage in long periods of drought: the animal can hang out in small water holes, hoping for better days.
But this ability It cannot be explained alone. This giant genome. Last Junehumble fern (Tmesipteris oblanceolata) which lives only on a handful of islands in the Pacific Ocean, has broken the record for the longest genome of any organism, plant and animal combined: 160 billion base pairs. That’s 11 billion more than the previous record holder—and still enormous—a flowering plant called Paris JaponicaWhich can reach a height of 75 cm.
Biologists They have no explanation for the benefit. Of these ambitious genomes. In theory, a larger genome It means spending more energy. For a living organism, it must constantly “access” the parts of the genome that produce the proteins necessary for its proper functioning. However, this fish has about 20,000 genes capable of encoding proteins. By comparison, humans, whose genome is 30 times smaller, also have about 20,000 genes capable of encoding proteins. Does this mean that everything else in this giant genome is useless? The question remains.
One thing is for sure, at the rate at which these records have been broken in recent years, the list may not be complete yet.
