Marcela Uliano da Silva’s Crusade Against the Golden Mussel

The Golden Mussel’s Worst Nightmare

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Why you should care

Because this molecular biologist believes that DNA sequencing is the key to protecting the Amazon River from an invasive mussel species. 

Save the Earth by killing it? Sure, but only a little part of it. So goes the philosophy of young superstar Brazilian biologist Marcela Uliano da Silva, who wants to eradicate a foreign species encroaching on the Amazon River’s shores: the golden mussel.

It’s controversial.

But before she can stamp out the mussel, she’s decided to arm herself with the nerdiest of all weapons … sequencing the invasive species’ genome. The golden mussel began its life in the Americas as a stowaway on Chinese ships in the 1990s; within about a decade, it looks set to fully invade Amazonian waters. And it’s already vastly altered its new environment, killing some existing inhabitants. Which means bad news if the hardy bivalves reach the Amazon River — home to the most numerous freshwater fish species in the world.

Her game plan?  Identify and target the genes that underlie the mussel’s MO instead of relying on chemicals that also harm neighboring species.

Invasive species are migrants, a product of globalization — and the golden mussel is just one example of the many foreign bodies that could threaten native environments in the coming years.

“The Amazon River is very precious,” said Uliano da Silva, a Ph.D. student at the Federal University of Rio de Janeiro.

And its treasure isn’t just theoretical — it’s got some dollar signs attached to it: Golden mussels have already begun clogging power plant pipes, incurring losses of $20,000 a day.


But while the idea of attacking an invader species isn’t new, Uliano da Silva’s high-tech approach is significant, especially because it comes from a youngster in the science research world: a 27-year-old with Hollywood-blond hair and no Ph.D. … yet. Instead of introducing predators to the environment that then take over, or spraying chlorine and other chemicals — think chemotherapy for the environment — she wants to use a laser focus — think surgery — to target the genes that underlie the mussel’s MO. One strategy? To inject mussels in the lab with molecules called silencing RNAs that recognize and turn off only golden mussel survival genes. These modified mussels would then be released into the wild to breed so that future generations won’t express these genes, either.

Uliano da Silva’s work is a helluva lot more interesting than what ecologists typically rely on to eradicate invasive species; mostly, her colleagues depend on educational outreach and fighting for policy measures (like federal laws requiring ships to empty their ballasts — where golden mussels often hitch a ride — before they sail into the Amazon). Only in the past five years has DNA sequencing become cheap and user-friendly enough to wield against invasive species.

Marcela in front of tire with mussels on it on dock

Marcela on the dock in front of a tire with mussels on it.

So far, other researchers are developing a “lampricide ” that silences genes crucial for embryonic development in lampreys invading the upper Great Lakes. Biotech startup Cotyledon Consulting is devising a similar strategy against invasive plants in Victoria, Canada. What Uliano da Silva is working on could be the face of a smart new way to think about ecology.

You have to be able to live in agony. Otherwise, you’re not going to do great things.

But plenty of sequencing’s possibility is still theoretical, said Daniel Simberloff, a professor of ecology at the University of Tennessee. “A number of ideas have been floated … but there’s been very little in the way of development.” 

Others warn that altered genes could undergo further changes when introduced to the wild — with unexpected, and possibly undesirable, consequences. “We know that evolution does not stop,” said James Collins, a professor of evolutionary biology at Arizona State University. How can scientists be certain that Mother Nature won’t tamper with their handiwork? 

The daughter of a salesman and housewife, Uliano da Silva led a frugal childhood in the small metropolis of Criciúma (population less than 200,000) so she could afford to attend private school — “the only way” to ensure admission to a top university in Brazil, she said. Her dad worked constantly, and her family spent holidays close to home. She started tuning in to the Discovery Channel — mainly because of her best friend, a biology geek. Which soon evolved into a bona fide passion, and she went on to study molecular and cell biology on scholarship at the Federal University of Santa Catarina.

She met her Ph.D. adviser, Mauro Rebelo, as an undergraduate, when she presented her research at a local university — an opportunity open only to Ph.D. students. Undaunted, she had applied to be a presenter and was accepted anyway. That’s a ballsy move in the science research world, whose unspoken hierarchy relegates inexperienced undergrads to the bottom of the totem pole. Rarely are they expected to conduct, much less present, their own research. 

“Every day, I’m anxious,” Uliano da Silva said. “But you have to be able to live in agony. Otherwise, you’re not going to do great things. … You cannot be safe. You need to take risks.” 

Rebelo describes Uliano da Silva as “idealistic … curious and determined.”  But as with most people, “her strongest points … can also be her greatest weaknesses.” Her idealism can sometimes cloud her “real view of the world,” he says. Which is exactly what critics might say about her hopes that the intellectually rigorous exercise of DNA sequencing can have real impact — that these hopes are not anchored in convincing, concrete evidence. But if she’s right, then this is one big idea. And that steel-jawed resolve might make her just the person to halt the golden mussel’s relentless spread.

So far, Uliano da Silva has sequenced the golden mussel DNA regions that encode genes, or the transcriptome, outlining her findings in the journal PLOS ONE in July. She identified genes that enable the mussels to cling to boat hulls and other surfaces, resist disease even in crowded conditions, and thrive anywhere — from power plants to fishes’ digestive tracts.

Next up? She wants to engineer reproductive genes to generate and release sterile mussels, causing the population to perish over time — similar to the “designer mosquitoes” released in Brazil and other countries. And she’s successfully crowdfunded her $20,000 sequencing project —  a less common but emerging approach, as researchers struggle with limited government funding

For Uliano da Silva, protecting the Amazon River reflects a deeper philosophy about our role on the planet. “That’s one thing I really like about molecular biology,” she said. “Science is saying to us, ‘We are all related, from bacteria to humans, because we share the same genetic code.’”



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