Posted on 05/31/2024 11:41:20 AM PDT by Red Badger
Scientists hope the study of it and other giant genomes will shed light on species resilience.
The New Caledonian fork fern (Tmesipteris oblanceolate) possesses the largest genome yet found. ORIANE HIDALGO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The human genome is made up of 3 billion base pairs of DNA. But that’s nothing compared with the New Caledonian fork fern (Tmesipteris oblanceolate), a leafy, tendrilled plant native to several Pacific islands. Its genome contains an astonishing 160 billion base pairs, making it the largest genome ever discovered, researchers report today in iScience. The finding could help scientists understand how genomes grow so large, and how these massive sets of genes affect species’ adaptability and survival.
It’s a neat—but not totally unexpected—finding, notes Kenneth Birnbaum, a developmental biologist at New York University’s Center for Genomics & Systems Biology who was not a part of the research team. “Ferns are known for this. … These are classic chromosome hoarders.”
DNA is made up of base pairs, two molecules connected by hydrogen bonds. The smallest genome discovered so far belongs to the mammalian parasite Encephalitozoon intestinalis, with a paltry 2.25 million base pairs.
Plant genomes tend to be heftier, and scientists know plants with relatively large genomes tend to be longer lived, slower to reproduce, and more vulnerable to environmental stress. But there’s no clear relationship between the size of an organism’s genome and its physical or physiological intricacy, notes Rose Marks, a postdoctoral researcher at Michigan State University who studies plant genomics and was not part of the research team. “Genome size doesn’t correlate tightly with anatomical or organismal complexity,” she says. “It’s something we just don’t have a handle on yet.”
Enter Jaume Pellicer, a lead author of the study and a botanist at the Botanical Institute of Barcelona. He and colleagues weren’t looking to get into the record books. Rather, they were investigating what role repetitive DNA sequences played in the evolution of plants with exceptionally large genomes.
Knowing ferns often have notably long stretches of repetitive DNA, the team turned to the fork fern for analysis. The plant doesn’t stand out in the rainforests of the few Pacific islands, including New Zealand and New Caledonia, where it’s found, Pellicer notes. “It’s not a flowering plant, so it doesn’t get a lot of attention. I guess the beauty is on the inside.”
The researchers used flow cytometry, a laser-based technique that analyzes cell characteristics, to tally the fern’s whopping 160 billion base pairs. That’s 11 billion more than the previous genome record holder, a Japanese flowering plant called Paris japonica. But “the million-dollar question,” Pellicer says, is why the fern possesses such a massive genome.
There are two primary ways that plants come by extra-large genomes. One is the wholesale copying of the genome inside the nucleus, known as polyploidy. The other is having a bevy of repetitive, noncoding DNA sequences. “We used to call [those sequences] junk DNA,” Pellicer says. But now researchers “know they have the ability to insert themselves in nearby genes and provide them with new functions or silence them.”
Yet, “It’s hard to imagine,” Birnbaum says, that producing vast quantities of noncoding DNA confers “some kind of selective advantage [to the fern]. It’s an incredible burden making DNA for every cell and then packaging it and then protecting it.”
Even as researchers continue to ponder why the fork fern has such a vast genome, however, they doubt they’ll find many eukaryotic organisms with genomes that are substantially larger. “We have a good understanding of genomes across families [of organisms],” Pellicer says, and the fern is likely close to the upper limit. “If we’re not at the upper end of the scale,” he says, “we’re close to it.”
Ping!...................
Because there’s no theory that predicts things like that.
There is ONE guy who knows and that’s God Almighty.
It has the highest intelligence of all the ferns and other than a few incidents in the Paleozoic era, has been mostly peaceful.
“But now researchers “know they have the ability to insert themselves in nearby genes and provide them with new functions or silence them.””
Uh oh. I have a real bad feeling about this. As if the globalist ghouls playing god don’t already have enough evil goals to tinker with....(not kidding...lol).
I’ve seen this movie.
It doesn’t end well...................
Genome size past a certain point is not correlated to complexity of the organism.
Amoebas have large genomes for example.
A lot of DNA is along for the ride simply because it can.
“I’ve seen this movie.
It doesn’t end well...................”
No. Not well at all. At least, not for us hoomans.
It’s just data. When they do decode it, it will read “Your time is up. Best regards, God” Bummer.
In their ignorance, scientists don’t have an explanation for certain DNA sequences, so they call it “junk” DNA. THEN it turns out not to be.
That’s why it’s hard to trust them when they talk about settled science.
No one knows.
No theories have ever predicted genomic findings.
As opposed to molecular biological, with RNA translation being the classic example.
Exactly
Yeah, my fern’s always bragging about it, what a pain. ;^)
Thanks Red Badger.
Tell your fern it better straighten up or it’s going to the “
Fern-ace.
I told it I’d hire the Mob to plant it.
If that happens, it’ll be a frond memory.
And to think we get excited when a chubby, drooling, human baby manages for its thumb to find its mouth:
https://www.youtube.com/watch?v=xN8c_X0LNcg&ab_channel=Learjet15
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
