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LOGAN — A surprising new scientific discovery at Utah State University may lead to a better understanding of why the largest living organism in Utah — an aspen grove called Pando — is dying.
The discovery has to do with an amazing thing about aspens; they don't need seeds to spread. They can spread through the ground putting out suckers that turn into trees. It's the secret behind Pando, which covers 106 acres near Fish Lake, tens of thousands of trees, one giant plant. And it's dying, failing to regenerate possibly because of genetics, scientists say.
Aspens all over the West are dying, and it's one of the things that prompted Karen Mock and Paul Wolf to take samples all over North America looking for clues in aspen leaves, nearly 3,000 of them.
They're trying to understand the genetics, and they have found something unusual about a surprising number of aspen trees that may be at the root of the problem: "Normally, you see two copies of every gene, but we were starting to see three copies of every gene," said USU Biology Professor Paul Wolf.
In other words, many aspen leaves have 50 percent extra DNA — three copies of every chromosome instead of two.
- Latin for "I Spread"
- Among the oldest known living organisms
"It was much more common than we thought," Wolf said. "This is a relatively rare phenomenon."
The finding is especially surprising because triple-chromosome trees are almost non-existent in the east. In the dry west they're all over the place, up to 68 percent of the aspen in some areas.
"Quite a surprise," said USU Population Geneticist Karen Mock. "And in fact we didn't quite believe it at first. So we kept running different kinds of tests to confirm it."
The significance? Triple chromosome trees rarely make seeds.
"The triploids are very likely to be sterile, which is a very interesting aspect of the thing," Mock said. "Because they have three copies, they can't undergo cell division properly."
Like, Pando, most triple-chromosome trees propagate by spreading suckers under the ground.
"We don't know if triploidy may be a factor in Pando's size and, or a factor in Pando's apparent mortality," Mock said.
That's the question no one can answer yet: are triple chromosomes a survival advantage or a disadvantage?
"We don't know," Mock said. "But we do know to ask it now. And that's something we didn't know before."
The researchers are designing new studies to see if they can figure out if this surprising discovery is good news or bad news for the aspen.