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Sea urchins made to order: Scripps scientists make transgenic breakthrough

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Sea urchins made to order: Scripps scientists make transgenic breakthrough

Consider the sea urchin. Specifically, the painted urchin: Lytechinus pictus, a prickly Ping-Pong ball from the eastern Pacific Ocean.

The species is a smaller and shorter-spined cousin of the purple urchins devouring kelp forests. They produce massive numbers of sperm and eggs that fertilize outside of their bodies, allowing scientists to watch the process of urchin creation up close and at scale. One generation gives rise to the next in four to six months. They share more genetic material with humans than fruit flies do and can’t fly away — in short, an ideal lab animal for the developmental biologist.

Scientists have been using sea urchins to study cell development for roughly 150 years. Despite urchins’ status as super reproducers, practical concerns often compel scientists to focus their work on more easily accessible animals: mice, fruit flies, worms.

Scientists working with mice, for example, can order animals online with the specific genetic properties they are hoping to study — transgenic animals, whose genes have been artificially tinkered with to express or repress certain traits.

Researchers working with urchins typically have to spend part of their year collecting them from the ocean.

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“Can you imagine if mouse researchers were setting a mousetrap every night, and whatever it is they caught is what they studied?” said Amro Hamdoun, a professor at UC San Diego’s Scripps Institution of Oceanography.

UC San Diego professor Amro Hamdoun holds a painted urchin. His breakthrough creating the creatures could lead to developments in science and medicine.

(Sandy Huffaker / For The Times)

Marine invertebrates represent about 40% of the animal world’s biological diversity yet appear in a scant fraction of a percentage of animal-based studies. What if researchers could access sea urchins as easily as mice? What if it were possible to make and raise lines of transgenic urchins?

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How much more could we learn about how life works?

“You know how during the pandemic, everyone was making sourdough? I’m not good at making sourdough,” Hamdoun said recently at his office in Scripps’ Hubbs Hall. He set his sights instead on a project of a different sort: a new transgenic lab animal, “a fruit fly from the sea.”

In March, Hamdoun’s lab published a paper on the bioRxiv preprint server demonstrating the successful insertion of a piece of foreign DNA — specifically, a fluorescent protein from a jellyfish — into the genome of a painted urchin that passed the change down to its offspring.

The result is the first transgenic sea urchin, one that happens to glow like a Christmas bulb under a fluorescent light. (The paper has been submitted for peer review.)

The animals are the first transgenic echinoderms, the phylum that includes starfish, sea cucumbers and other marine animals. Hamdoun’s mission is to make genetically modified urchins available to researchers anywhere, not just those who happen to work in research facilities at the edge of the Pacific Ocean.

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Elliot Jackson, a postdoctoral researcher, works with sea urchin eggs in a lab at Scripps

Postdoctoral researcher Elliot Jackson works with sea urchin eggs in a lab at Scripps.

(Sandy Huffaker / For The Times)

“If you look at some of the other model organisms, like Drosophila [fruit flies], zebrafish and mouse, there are well-established resource centers,” said Elliot Jackson, a postdoctoral researcher at Scripps and lead author of the paper. “If you want a transgenic line that labels the nervous system, you could probably get that. You could order it. And that’s what we hope we can be for sea urchins.”

Being able to genetically modify an animal supercharges what scientists can learn from it, with implications far beyond any individual species.

“It will transform sea urchins as a model for understanding neurobiology, for understanding developmental biology, for understanding toxicology,” said Christopher Lowe, a Stanford professor of biology who was not involved in the research.

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The lab’s breakthrough, and its focus on making the animals freely available to fellow scientists, will “allow us to explore how evolution has solved a lot of really complicated life problems,” he said.

Researchers tend to study mice, flies and the like not because the animals’ biology is best suited to answer their questions but because “all the tools that were necessary to get at your questions were built up in just a few species,” said Deirdre Lyons, an associate professor of biology at Scripps who worked with Hamdoun on early research related to the project.

Expanding the range of animals available for sophisticated lab work is like adding colors to an artist’s palette, Lyons said: “Now you can go get the color that you really want, that best fits your vision, rather than being stuck with a few models.”

Hamdoun holds two painted urchins in an outstretched hand

Painted urchins and humans live vastly different lives but genetically are quite similar.

(Sandy Huffaker / For The Times)

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On the ground floor of Hamdoun’s office building is the Hubbs Hall experimental aquarium, a garage-like space crammed with tanks full of recirculating seawater and a motley assortment of marine life.

On a recent visit, Hamdoun reached into a tank and gently dislodged a painted urchin. It scooched with surprising speed across an outstretched palm, as if exploring alien terrain.

The last common ancestor of L. pictus and Homo sapiens lived at least 550 million years ago. Despite the different evolutionary paths we’ve since traveled, our genomes reveal a shared biological heritage.

The genetic instructions that drive the transformation of a single zygote into a living body are strikingly similar in our two species. Specialized systems differentiating from a single fertilized egg and the translation of a jumble of proteins into a singular living thing — on the cellular level, all of that proceeds in much the same way for urchins and people.

These animals are “really fundamental to our understanding of all of life,” Hamdoun said, placing the urchin back in its tank. “And historically, very inaccessible genetically.”

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The experimental aquarium was built in the 1970s, when scooping life from the sea was the only way to acquire research specimens. A few floors up in Hubbs Hall, Hamdoun led the way into the urchin nursery — the first large-scale effort to raise successive generations of the animals in a laboratory. At any given moment, the team has 1,000 to 2,000 sea urchins in various stages of development.

Hamdoun points at rows of greenish tanks holding sea urchins

Hamdoun points to transgenic sea urchins his lab is raising at Scripps.

(Sandy Huffaker / For The Times)

Row upon row of tiny plastic tanks stood against a wall, each containing a lentil-size juvenile urchin. A strip of tape on each tank noted the animal’s genetic modification and date of fertilization. On some, a second bit of tape indicated animals that had the modification in their sex cells’ DNA, meaning it could be passed down to offspring. (For this reason, the lab keeps its urchins scrupulously separate from the wild population.)

“One of the big questions in all of biology is to understand how the series of instructions in the genome gives you whatever phenotype you want to study,” Hamdoun said — essentially, how the string of amino acids that is an animal’s genetic code gives rise to the characteristics of the living, respiring creature. “One of the fundamental things you have to do is be able to modify that genome, and then study what the outcome is.”

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He pointed to a tank containing a tiny urchin from whose genetic code the protein ABCD1 has been snipped.

ABCD1 acts like a bouncer, Hamdoun explained, parking along the cell membrane and ejecting foreign molecules. The protein’s action can preserve the cell from harmful substances but can sometimes work against an organism’s best interest, as when it prevents the cell from absorbing a necessary medication.

Researchers using urchins in which that protein no longer works can study the movement of a molecule through an organism — DDT, for example — and measure how much of the substance ends up in the cell without the confounding interference of ABCD1. They can reverse-engineer how big a role ABCD1 plays in preventing a cell from absorbing a drug.

A transgenic fluorescent sea urchin glows green through a microscope

One biology professor said Scripps’ work will transform sea urchins as a model for research.

(Sandy Huffaker / For The Times)

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And then there are the fluorescent urchins.

“The magic happens in this room,” Jackson said, walking into a narrow office with $1 million worth of microscopes at one end and a decades-old hand-cranked centrifuge bolted to a table at another.

He placed a petri dish containing three pencil-eraser-size transgenic urchins under a microscope. At 120 times its size, each looked like the Times Square New Year’s Eve ball come to life — a glowing, wiggling creature of pentamerous radial symmetry.

Fluorescence is not just an echinoderm party trick. Lighting up the cells makes it easier for researchers to track their movement in a developing organism. Researchers can watch as the early cells of a blastula divide and reorganize into neural or cardiac tissue. Eventually, scientists will be able to turn off individual genes and see how that affects development. It will help us understand how our own species develops, and why that development doesn’t always proceed according to plan.

The lab has “done a great job. It’s really been welcomed by the community,” said Marko Horb, senior scientist and director of the National Xenopus Resource at the University of Chicago’s Marine Biological Laboratory.

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Horb runs the national clearinghouse for genetically modified species of Xenopus, a clawed frog used in lab research. Funded in part by the National Institutes of Health, the center develops lines of transgenic frogs for scientific use and distributes them to researchers.

Hamdoun envisions a similar resource center for his lab’s urchins. They’ve already started sending tiny vials of transgenic urchin sperm to interested scientists, who can grow bespoke urchins with eggs acquired from Hamdoun’s lab or another source.

Hamdoun vividly recalls the time he spent earlier in his career trying to track down random snippets of DNA necessary for his research, the disappointment and frustration of writing to professors and former postdocs only to find that the material had long been lost. He’d rather future generations of scientists spend their time on discovery.

“Biology is really interesting,” he said. “The more people can get access to it, the more we’re going to learn.”

Sea urchins in a microscope dish

Three transgenic sea urchins in a petri dish.

(Sandy Huffaker / For The Times)

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‘It is scary’: Oak-killing beetle reaches Ventura County, significantly expanding range

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‘It is scary’: Oak-killing beetle reaches Ventura County, significantly expanding range

A tiny beetle responsible for killing hundreds of thousands of oak trees in Southern California has reached Ventura County, marking a troubling expansion.

This is the farthest north the goldspotted oak borer has been found in the state. Given the less-than-one-half-inch insect’s track record of devastating oaks since being first detected in San Diego County in 2008, scientists and land stewards are alarmed — and working to contain the outbreak.

“We keep seeing these oak groves getting infested and declining, and a lot of oak mortality,” said Beatriz Nobua-Behrmann, an ecologist with UC Agriculture and Natural Resources. “And as we go north, we have tons of oak woodlands that are very important ecosystems over there. It can even get into the Sierras if we don’t stop it. So it is scary.”

A goldspotted oak borer emerges from a tree.

(Shane Brown)

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Although officials are only now reporting the arrival, they first found the beetle in Ventura County in the summer of 2024. Julie Clark, a community education specialist at the UC program, recalled getting a call from a local forester who spotted an unhealthy-looking coast live oak while driving in the Simi Hills’ Box Canyon.

“He saw dieback. He saw all the leaves on the crown were brown, which is one of the characteristic signs of a GSOB infestation,” Clark said in a blog post published this week, using the acronym for the invasive insect.

The forester examined the tree and found D-shaped holes — the calling card of the goldspotted oak borer — where the beetles had chewed through the tree to emerge from the bark.

Foresters debarked and chipped the highly infested tree to kill the beetles inside. Surrounding trees, however, were not afflicted.

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Still, the beetle continued its march in the county. In April, another dead, beetle-infested oak was found in Santa Susana, according to the California Department of Forestry and Fire Protection. A month later, several more dead and injured trees were discovered.

The beetle, named for six gold spots that adorn its back, doesn’t fly far. It reaches faraway areas by hitching a ride on firewood. Nobua-Behrmann, an urban forestry and natural resources advisor, is among a contingent calling for regulations limiting the movement of firewood.

The goal, they say, is to prevent the slaughter of the state’s iconic oaks.

The beetles lay their eggs on oaks. When the larvae hatch, they bore in to reach the cambium. The cambium is like a tree’s blood vessels, carrying water and nutrients up and down. The insect chews through the layer, and eventually the damage is akin to putting a permanent tourniquet on the tree.

An infested tree will often display a thinning canopy and red or black stains on the trunk, injured areas where the tree is attempting to force out insects. The “confirming sign” is the roughly eighth-inch exit hole.

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In the Golden State, the beetles are attacking the coast live oak, canyon live oak and the California black oak.

The goldspotted oak borer is native to Arizona, where the ecosystem is adapted to it and it doesn’t kill many trees. It’s believed that it traveled to San Diego County via firewood. It has since been found in L.A., Orange, Riverside and San Bernardino counties, and, according to research by UC Riverside, has killed an estimated 200,000 oak trees.

In 2024, the beetle was discovered in several canyons in Santa Clarita, putting it just 14 miles from the roughly 600,000 coast live oaks in the Santa Monica Mountains. Reaching the scenic coastal mountain range was described as “the worst case scenario” for L.A. County in a 2018 report.

Researchers, fire officials and land managers, among others, are working to control or slow the beetles’ death march. They acknowledge they’re unlikely to be eradicated in the areas where they’ve settled in.

Experts advise removing and properly disposing of heavily infested trees, and that entails chipping them. (To kill the minute beetle, chips must be 3 inches in diameter or smaller.)

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If trees are lightly or not yet infested, they can be sprayed or injected with insecticides.

However, there are drawbacks to the current options. Pesticides may harm nontarget species, such as butterflies and moths. And the treatment can be expensive and laborious, making it impractical for vast swaths of forest.

There’s another nontoxic tactic in play: educating the public to report possible infestations and burn firewood where they buy it.

People can also volunteer to survey trees for signs of the dreaded beetle, allowing them to “do something instead of just worrying about it,” Nobua-Behrmann said.

UC Agriculture and Natural Resources, along with the Cal Fire, is hosting a “GSOB Blitz” surveying event next month in Simi Valley.

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With a nudge from industry, Congress takes aim at California recycling laws

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With a nudge from industry, Congress takes aim at California recycling laws

The plastics industry is not happy with California. And it’s looking to friends in Congress to put the Golden State in its place.

California has not figured out how to reduce single-use plastic. But its efforts to do so have created a headache for the fossil fuel industry and plastic manufacturers. The two businesses are linked since most plastic is derived from oil or natural gas.

In December, a Republican congressman from Texas introduced a bill designed to preempt states — in particular, California — from imposing their own truth-in-labeling or recycling laws. The bill, called the Packaging and Claims Knowledge Act, calls for a national standard for environmental claims on packaging that companies would voluntarily adhere to.

“California’s policies have slowed American commerce long enough,” Rep. Randy Weber (R-Texas) said in a post on the social media platform X announcing the bill. “Not anymore.”

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The legislation was written for American consumers, Weber said in a press release. Its purpose is to reduce a patchwork of state recycling and composting laws that only confuse people, he said, and make it hard for them to know which products are recyclable, compostable or destined for the landfill.

But it’s clear that California’s laws — such as Senate Bill 343, which requires that packaging meet certain recycling milestones in order to carry the chasing arrows recycling label — are the ones he and the industry have in mind.

“Packaging and labeling standards in the United States are increasingly influenced by state-level regulations, particularly those adopted in California,” Weber said in a statement. “Because of the size of California’s market, standards set by the state can have national implications for manufacturers, supply chains and consumers, even when companies operate primarily outside of California.”

It’s a departure from Weber’s usual stance on states’ rights, which he has supported in the past on topics such as marriage laws, abortion, border security and voting.

“We need to remember that the 13 Colonies and the 13 states created the federal government,” he said on Fox News in 2024, in an interview about the border. “The federal government did not create the states. … All rights go to the people in the state, the states and the people respectively.”

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During the 2023-2024 campaign cycle, the oil and gas industry was Weber’s largest contributor, with more than $130,000 from companies such as Philips 66, the American Chemistry Council, Koch Inc. and Valero, according to OpenSecrets.org.

Weber did not respond to a request for comment. The bill has been referred to the House Energy and Commerce Committee.

Plastic and packaging companies and trade organizations such as Ameripen, Keurig, Dr Pepper, the Biodegradable Plastics Industry and the Plastics Industry Assn. have come out in support of the bill.

Other companies and trade groups that manufacture plastics that are banned in California — such as Dart, which produces polystyrene, and plastic bag manufacturers such as Amcor — support the bill. So do some who could potentially lose their recycling label because they’re not meeting California’s requirements. They include the Carton Council, which represents companies that make milk and other beverage containers.

“Plastic packaging is essential to modern life … yet companies and consumers are currently navigating a complex landscape of rules around recyclable, compostable, and reusable packaging claims,” Matt Seaholm, chief executive of the Plastics Industry Assn., said in a statement. The bill “would establish a clear national framework under the FTC, reducing uncertainty and supporting businesses operating across state lines.”

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The law, if enacted, would require the Federal Trade Commission to work with third-party certifiers to determine the recyclability, compostability or reusability of a product or packaging material, and make the designation consistent across the country.

The law applies to all kinds of packaging, not just plastic.

Lauren Zuber, a spokeswoman for Ameripen — a packaging trade association — said in an email that the law doesn’t necessarily target California, but the Golden State has “created problematic labeling requirements” that “threaten to curtail recycling instead of encouraging it by confusing consumers.”

Ameripen helped draft the legislation.

Advocates focused on reducing waste say the bill is a free pass for the plastic industry to continue pushing plastic into the marketplace without considering where it ends up. They say the bill would gut consumer trust and make it harder for people to know whether the products they are dealing with are truly recyclable, compostable or reusable.

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“California’s truth-in-advertising laws exist for a simple reason: People should be able to trust what companies tell them,” said Nick Lapis, director of advocacy for Californians Against Waste. “It’s not surprising that manufacturers of unrecyclable plastic want to weaken those rules, but it’s pretty astonishing that some members of Congress think their constituents want to be misled.”

If the bill were adopted, it would “punish the companies that have done the right thing by investing in real solutions.”

“At the end of the day, a product isn’t recyclable if it doesn’t get recycled, and it isn’t compostable if it doesn’t get composted. Deception is never in the public interest,” he said.

On Friday, California’s Atty. Gen. Rob Bonta announced settlements totaling $3.35 million with three major plastic bag producers for violating state law regarding deceptive marketing of non-recyclable bags. The settlement follows a similar one in October with five other plastic bag manufacturers.

Plastic debris and waste is a growing problem in California and across the world. Plastic bags clog streams and injure and kill marine mammals and wildlife. Plastic breaks down into microplastics, which have been found in just about every human tissue sampled, including from the brain, testicles and heart. They’ve also been discovered in air, sludge, dirt, dust and drinking water.

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‘Largest outbreak that we’ve seen in California.’ Death cap mushrooms linked to deaths, hospitalizations

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‘Largest outbreak that we’ve seen in California.’ Death cap mushrooms linked to deaths, hospitalizations

An exceptionally wet December has contributed to an abundance of death cap mushrooms, or Amanita phalloides, on the Central Coast and Northern California, causing what officials describe as an unprecedented outbreak of severe illness and death among people who consume the fungi.

Public health officials are issuing a second warning this winter, this time urging the public against foraging for wild mushrooms, noting that many people have mistakenly eaten the death cap that, when consumed, can cause severe liver damage and in some causes death.

In the last 26 years, “we have not had a season as deadly as this season both in terms of the total numbers of cases as well as deaths and liver transplants,” said Craig Smollin, medical director of the San Francisco division of the California Poison Control System.

“I believe this is probably the largest outbreak that we’ve seen in California, ever.”

Many of the cases, officials say, have involved people from Mexico and elsewhere for whom the death cap resembles an edible mushroom in their home countries.

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The California Department of Public health reported 35 death cap-related illness, including three fatalities and three liver transplants between Nov. 18 and Jan. 6. Affected people were between the ages of 19 months old and 67 years old.

In a typical year, the California Poison Control Center may receive up to five cases of poisonous mushroom-related illness, according to authorities.

The last major outbreak of mushroom-related illness in California occurred in 2016 with 14 reported cases and while there were no deaths, three people required liver transplants and one child suffered a “permanent neurologic impairment.”

The death cap is the world’s most poisonous mushroom, responsible for 90% of mushroom-related fatalities.

Where the death-cap outbreak is concentrated

When state public health officials first warned of the dangers of the death-cap mushroom in December, significant clusters of reported illness occurred in Monterey and the San Francisco bay areas.

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Reported hospitalizations have since grown to include Alameda, Contra Costa, Monterey, San Francisco, San Luis Obispo, San Mateo, Santa Clara, Santa Cruz and Sonoma counties.

Death cap mushrooms are known to sprout across the state of California but they thrive in shady, humid or moist environments under live oak and cultivated cork oak trees.

Death cap mushrooms bloom particularly well after the fall and winter rains. Once they sprout, its tall and graceful characteristics are very conspicuous and catch people’s eye, said David Campbell, an expert on mushroom consumption or a mycophagist.

Who is mistakenly eating the death cap

People who have accidentally consumed the death cap were usually foraging for mushrooms in the wilderness, either alone or with a group, officials say.

Among the affected are monolingual speakers of Spanish, Chinese, Mandarin and Mixteco as well as foragers who may confuse the death cap mushroom for edible fungi from their native countries, according to experts.

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“So they have a false sense of security in their knowledge, thinking they know what they’re doing but that only applies to where they’re from,” Campbell said.

“We’re seeing that a number of patients do seem to have a Hispanic background,” said Dr. Rita Nguyen, assistant state public health officer at the California Department of Public Health.

In November, a Salinas family said they went on a hike in their community and found the death cap which looked similar to an edible mushroom they would forage for in their hometown in Oaxaca, KSBW Action News reported.

Laura Marcelino and Carlos Diaz took the mushrooms home, cooked them and ate them — their children did not. They both threw up, had diarrhea for an entire day and were later hospitalized, KSBW Action News reported. Marcelino’s condition improved but Diaz’s health declined exponentially to the point that he fell into a coma and was put on a list to receive a liver transplant, according to news reports.

Why people are mistakenly eating death cap mushrooms

The three most deadly mushrooms in California include the death cap, destroying angel (Amanita ocreata) and deadly Galerina (Galerina marginata), according to the Bay Area Mycological Society.

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The death cap mushroom has a dome-shape smooth cap with olive or yellowish-green tones. On the underside of its cap are white gills and spores.

It can be confused with the mushroom species Volvariella, which is edible.

These mushrooms appear similar because they have a volva, a cup-like structure at the base of the mushroom’s stem, and are white-ish, but lack one important key characteristic annulus, or ring, around its stem, said Ari Jumpponen, Kansas State University distinguished professor of biology.

Jumpponen said some Volvariella species can be found in Oaxaca.

What symptoms can you expect after eating a death cap?

No amount of death cap is safe to consume.

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“I also want to just stress that there’s nothing, there’s no cooking of the mushroom or freezing of the mushroom that would inactivate the toxin,” Smollin said.

The poisonous toxins from the death cap can result in a delayed gastrointestinal symptoms that may not appear until 6 to 24 hours after eating it.

Some of the early symptoms that can go away within a day include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Drop in blood pressure
  • Fatigue
  • Confusion

Mild symptoms may only be the beginning of a more severe reaction.

Severe symptoms can develop within 48 to 96 hours, include progressive liver damage and, in some cases, full liver failure and potentially death, Smollin said.

If you’ve eaten a foraged mushroom and start to exhibit any adverse symptoms, call California’s poison control hotline at 1-800-222-1222 for free, confidential expert advice in multiple languages. If you suspect mushroom poisoning, call 911.

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