Thomas R. O'Donnell

U of I professors slimed for their snail research

In University research on April 15, 2013 at 1:00 pm
snails

Potamopyrgus antipodarum, the New Zealand snail under scrutiny. Image © Bart Zijlstra / http://www.bartzijlstra.com via University of Iowa.

At first, it may sound completely ridiculous: a four-year, $876,000 grant from the federal National Science Foundation (NSF) to study “snail sex.”

That’s how a conservative news website branded it – wrongly. And it’s how two University of Iowa researchers and their California colleague found themselves at the center of the latest debate on government’s role in supporting basic science research, a debate that started with a similar attack on duck penis research.

If you don’t believe this is a big deal, type “snail sex” into your favorite search engine. Since March 27, when the conservative news (and I use that term advisedly) website CNSNews.com posted the item, numerous right-wing blogs and commentators have scorned the investigation as an example of wasteful government spending. Other bloggers have defended the research and the researchers, U of I biology professors Maurine Neiman and John Logsdon and Jeffrey Boore, an adjunct professor at the University of California, Berkeley, and chief executive officer of Genome Project Solutions, Inc.

Snail sex came up on HBO’s Real Time with Bill Maher in a debate about science and the federal deficit. Zack Kopplin, who made a case for basic science research on that program, also defended the U of I snail project on the NPR Science Friday program last week.

The “snail sex” kerfuffle came just a week after CNSNews.com posted a similar item about a Yale University study of waterfowl genitalia that instantly became known as the “duck penis research.” It, too, set off a wave of outrage and a similar outpouring of defenders. The researcher in question, Patricia Brennan, even issued her own response in a Salon article.

Logsdon, who’s received NSF support before, wasn’t too shocked when conservatives targeted the snail project. Having grown up in the years of William Proxmire’s attention-getting Golden Fleece Award, he said, he’s wondered when his research into sex among organisms like tiny protists and rotifers would get this kind of attention.

But he’s disappointed no one bothered to ask him or Neiman about it. “Even though this thing has gone semiviral, it’s perhaps not surprising that there’s been nearly no follow-up with the researchers here.”

Neiman said the extent of her contact with the press was an email from the CNSNews reporter. Under the guise of writing an article about the federal sequester’s effects on science research, he asked her to confirm the amount of the grant. “I said, ‘Yup, that’s it,’” Neiman said. She later got a call from a Fox network reporter with the same question. “Not that my expectations are high for the conservative press,” she adds, “but there was zero effort on their part” to understand the science and its implications.

The press and the bloggerati have kicked the issue around for more than two weeks, but I’m the only writer who’s asked the Iowa professors to explain their research.

At the heart of the outrage is the perception, as Logsdon said, that President Barack Obama is writing them a check. (Of course, in previous years it would have been President George W. Bush writing the checks.)

The reality is that this and other grants are awarded competitively. Panels of scientists in the same or similar fields review each proposal anonymously, weighing them against dozens of others. Recent NSF statistics show that it funded only about a fifth of the proposals made to its Molecular and Cellular Biosciences program in the Directorate of Biological Sciences, the program that funded Neiman and Logsdon. The fact that experts and the NSF chose the snail research indicates that questions about sex’s advantages are important and the project is well designed to get at answers.

If other media outlets had taken a deeper look at the NSF proposal, they might have seen how the snail project addresses some of the most fundamental, persistent questions of biology and evolution, with ramifications for human health and the environment.

This is not about why or how snails have sex. It’s about why any species has sex.

In essence, biologists have long been puzzled by why organisms developed sexual reproduction. Sexual reproduction is costly in time and energy. Asexual reproduction (essentially an organism cloning itself) is more efficient. And sexual reproduction also generally isn’t in an organism’s biological interest because it means passing on only half its genes.

“Theory suggests that sex must be beneficial because sexual females waste half of their reproductive investment on offspring that themselves cannot reproduce directly: males. In other words, such a costly trait as sex would not be so common if it didn’t confer profound benefits,” Neiman and Logsdon wrote in an email.

So what genetic and evolutionary advantages does sexual reproduction offer? The theory is that it provides genetic diversity and counters the propagation of harmful mutations. But sexual reproduction also can produce harmful mutations and, anyway, where’s the genetic proof of sexual reproduction’s advantages?

Researchers have put forth hypothetical conditions under which sex can succeed, but “we are still a long way from collecting the data that allow us to rigorously test these hypotheses,” Neiman and Logsdon wrote. That’s what their research is about.

The models scientists typically have used to study reproduction, like fruit flies (sexual) or yeasts (asexual), are inadequate because you can’t compare genetic information from sexual and asexual organisms in species with the same genetic backgrounds.

That’s where Potamopyrgus antipodarum comes in. This New Zealand snail has two lineages, one that reproduces sexually and one that reproduces asexually. While the species typically reproduces sexually, occasionally a female will asexually create a daughter, for unknown reasons the team hopes to explore. Those daughters and their offspring reproduce asexually only, creating two genetic lines the researchers can compare.

Despite the headlines about “snail sex,” Neiman, Logsdon and Boore aren’t peering into snail bedrooms like nonvertebrate fetishists (although the Iowa researchers say there are reasons to study behavior, too). They’re using the latest gene-reading technology to study the DNA of the different snails and compare them. They’re looking at how the genomes of sexually reproducing snails compare with those that reproduce asexually. By observing how mutations accumulate and genes are preserved or lost, they hope to get at the real, fundamental reasons for or against sexual reproduction.

Most of the NSF money is going into compiling and comparing snail DNA sequences, Neiman and Logsdon said, but a lot also is spent training high school, undergraduate and graduate students and early-career researchers. They learn to compile and analyze genomic data, skills that will enable them to continue on the path to discovery.

And some grant money goes to engage the community, with water quality workshops  and collaboration with tenth-grade biology students at a local high school. The students are helping develop and test curricula to teach thousands of other students about biology and genomics.

The research could provide other benefits. The team says P. antipodarum could be a powerful model for other biological questions, including host-parasite dynamics (important to preventing a devastating disease in developing countries). The snails are a problematic invasive species around the world, so learning more about them also could help find strategies to reduce their populations.

P. antipodarum also could be important to ecotoxicology, which addresses pollution’s impact on the environment and human health. For instance, Neiman said, estrogens are an increasing concern in water supplies. The New Zealand snails are especially sensitive to these hormones, which cause them to reproduce more. Monitoring snail populations could provide an early warning of estrogen contamination in lakes and ponds.

Because the snails live at the bottom of lakes, they also could provide clues to contamination from heavy metals and other pollutants. A complete genome for the species could be useful in understanding contaminants’ effects.

The researchers also think the snails could help understand the consequences of chromosome loss, since P. antipodarum often gains or loses single chromosomes. Chromosome loss is a major concern in human health, Neiman and Logsdon say, as a primary cause of infertility and cancer and the source of Down syndrome.

These are only a few possible applications for their research, Logsdon said, but there are more yet to be discovered. That’s the thing about basic research: It provides the kind of knowledge and serendipitous discoveries that lead to breakthroughs.

For example, another U of I researcher studying lung disease in humans contacted Neiman out of the blue, seeking more information about her snail research. “There may be important parallels between the mucus and cilia that characterize lung cells and the mucus and cilia that characterize snail movement,” she wrote in her email to me. The researchers plan to meet soon.

It’s a nascent connection, but, Logsdon said, “It’s an example of how we really can’t predict” how basic research will connect to other subjects. “It’s one reason we need to learn about the diversity of life” beyond humans.

Even given all this, Neiman understands the public’s hesitancy about supporting basic research. “I’m happy to have a conversation about how we should invest” tax dollars, she said, especially in a difficult economy. “I’m very sympathetic to the public wanting to understand how basic science works,” because there’s clearly a misperception – as their case shows.

In a future post, I’ll share my thoughts about the snail firestorm.

  1. […] money on scientific research to come on the heels of ‘duck penis research‘ is ‘snail sex.’ Research systems, like snail and duck sex, serve as important models for understanding […]

  2. How appropriate. Look at the article from Reuters today. It proves we need this research to stop an infestation that could be catastrophic across the US.

    ORLANDO, Florida (Reuters) – South Florida is fighting a growing infestation of one of the world’s most destructive invasive species: the giant African land snail, which can grow as big as a rat and gnaw through stucco and plaster.

    More than 1,000 of the mollusks are being caught each week in Miami-Dade and 117,000 in total since the first snail was spotted by a homeowner in September 2011, said Denise Feiber, a spokeswoman for the Florida Department of Agriculture and Consumer Services.

    Residents will soon likely begin encountering them more often, crunching them underfoot as the snails emerge from underground hibernation at the start of the state’s rainy season in just seven weeks, Feiber said.

    The snails attack “over 500 known species of plants … pretty much anything that’s in their path and green,” Feiber said.

    In some Caribbean countries, such as Barbados, which are overrun with the creatures, the snails’ shells blow out tires on the highway and turn into hurling projectiles from lawnmower blades, while their slime and excrement coat walls and pavement.

    “It becomes a slick mess,” Feiber said.

    A typical snail can produce about 1,200 eggs a year and the creatures are a particular pest in homes because of their fondness for stucco, devoured for the calcium content they need for their shells.

    The snails also carry a parasitic rat lungworm that can cause illness in humans, including a form of meningitis, Feiber said, although no such cases have yet been identified in the United States.

    EXOTIC INVASION

    The snails’ saga is something of a sequel to the Florida horror show of exotic species invasions, including the well-known infestation of giant Burmese pythons, which became established in the Everglades in 2000. There is a long list of destructive non-native species that thrive in the state’s moist, subtropical climate.

    Experts gathered last week in Gainesville, Florida, for a Giant African Land Snail Science Symposium, to seek the best ways to eradicate the mollusks, including use of a stronger bait approved recently by the federal government.

    Feiber said investigators were trying to trace the snail infestation source. One possibility being examined is a Miami Santeria group, a religion with West African and Caribbean roots, which was found in 2010 to be using the large snails in its rituals, she said. But many exotic species come into the United States unintentionally in freight or tourists’ baggage.

    “If you got a ham sandwich in Jamaica or the Dominican Republic, or an orange, and you didn’t eat it all and you bring it back into the States and then you discard it, at some point, things can emerge from those products,” Feiber said.

    Authorities are expanding a series of announcements on buses, billboards and in movie theaters urging the public to be on the lookout.

    The last known Florida invasion of the giant mollusks occurred in 1966, when a boy returning to Miami from a vacation in Hawaii brought back three of them, possibly in his jacket pockets. His grandmother eventually released the snails into her garden where the population grew in seven years to 17,000 snails. The state spent $1 million and 10 years eradicating them.

    Feiber said many people unfamiliar with the danger viewed the snails as cute pets.

    “They’re huge, they move around, they look like they’re looking at you … communicating with you, and people enjoy them for that,” Feiber said. “But they don’t realize the devastation they can create if they are released into the environment where they don’t have any natural enemies and they thrive.”

  3. […] I posted it about a week ago, more than 2,000 visitors have read my report on the conservative criticism directed at University of Iowa professors Maurine Neiman and John […]

  4. Dear Mr. O’Donnell,
    I would like to inform you the picture you used for this article is made by me so it’s under my copyright. You might not have known the original source as you mention the University of Iowa. It’s fine with me if you use the picture, but please at a credit line (© Bart Zijlstra / http://www.bartzijlstra.com) to the picture description. Thanks !

  5. […] on research that puts shrimp on tiny treadmills, asks questions of single people on speed dates, studies snail sex1, or examines farm-based tourism in rural China2. Senator Paul regularly complains about NSF, often […]

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