from the world's big
The strange genetic twist in Campbell's tomato soup
New research solves a long-standing puzzle.
- Breeders found a genetic tweak that made tomatoes easier to pick, but they didn't grow as well.
- Modern technology has revealed an ancient surprise hidden in the fruit.
- New research showcases how much we're still learning about crop gene editing.
It's certainly a classic: Campbell's Soup. How many lunchtimes have been elevated by its warm tomatoey goodness? To us, it's a comforting touchstone. To Campbell's, though, it's a business, and not just any tomato will do. What you may not realize about this old friend is that every bowl contains an odd solution to a genetic puzzle that's long mystified growers.
A new article from the Cold Spring Harbor Lab (CSHL) solves the riddle, however — the answer it presents serves as a cautionary tale about messing with Mother Nature.
Growing the perfect tomato
Image source: Smit / Shutterstock
When we think of a choice tomato, we're likely to picture a red, juicy orb of flavor, and Campbell's no doubt does, too. However, given the uncountably huge number of tomatoes they need for their soup, there are other considerations as well, such as the ease with which the fruit can be plucked from growers' vines by automated pickers.
Back in the 1960s, farmers noticed a tomato strain whose fruit came easily off the vine, cleanly separating at the tomato's top. What was unique about the plant was that its stems lacked a bend, or joint, so that when their fruit was gently pulled, they popped right off.
Using traditional plant-breeding techniques, Campbell's growers promoted this "j2" (for "jointless 2") mutation, ultimately developing a "jointless" tomato. However, the tomato had a problem: While it was easy to harvest, it would branch and flower before bearing much fruit. Lead CHSL researcher Zach Lippman recalls, "Even that first plant from Campbell company was described as having excessive branching."
Breeders in Florida persisted in trying new variants with j2. Eventually they stumbled across a plant that was both jointless and grew well, and the rest is tomato-soup history.
But not quite: It was an unexplained genetic solution to a problem, leaving j2 a "cryptic genetic variation." As Lipmann explains: "On its own, the single mutation has no obvious effect on the health or the fitness or the vigor of the plant. But when another mutation happens along with it and there is a negative interaction, that's the cryptic mutation revealing itself."
Modern tools solve the riddle
Image source: Kyselova Inna / Shutterstock
Lipmann and his colleague Sebastian Soyk analyzed the plants' genetic makeup and identified the interaction that caused the early branching and flowering. It was a conflict between j2 and an ancient gene mutation likely dating back 4,000 years. "The ancient mutation," asserts Lipmann, "normally 'breaks' the [j2] gene. It reduces the functional activity of that gene by 30 percent."
More surprising was the manner in which the Florida growers had inadvertently solved the conflict. One might imagine that they somehow managed to breed out the ancient gene, but that's not what happened. Their efforts produced a second copy of that ancient gene that cancelled out the first. It seems that this particular gene acts something like an on/off switch. Regarding this, Lipmann says, "If I suddenly have two copies of that mutated gene, we're back to nearly full functional activity. This duplication event was naturally occurring, so basically, nature provided the solution to its own problem."
Image source: Jiri Hera / Shutterstock
This odd little story underscores how much we still have to learn about genomes. "The example we presented is very a black and white case," Lippman says. "However, I'm pretty confident saying that there are going to be many examples of cryptic variation that are much more nuanced and subtle in their effects."
With powerful tools at our disposal such as CRISPR, we're still just at the beginning of our understanding, and there are far more critical, life-or-death, circumstances in which new technologies are being deployed. As CSHL found, though, Mother Nature continues to have some rabbits in her hat.
As Lipmann's research shows, "If you have a particular gene that you want to use to improve a trait, for example, by gene editing, it may very well be that the outcome is not going to be what you expected."
Construction of the $500 billion dollar tech city-state of the future is moving ahead.
- The futuristic megacity Neom is being built in Saudi Arabia.
- The city will be fully automated, leading in health, education and quality of life.
- It will feature an artificial moon, cloud seeding, robotic gladiators and flying taxis.
The Red Sea area where Neom will be built:
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A new study suggests that a century-old vaccine may reduce the severity of coronavirus cases.
- A new study finds a country's tuberculosis BCG vaccination is linked to its COVID-19 mortality rate.
- More BCG vaccinations is connected to fewer severe coronavirus cases.
- The study is preliminary and more research is needed to support the findings.
Professor Luis Escobar.
Credit: Virginia Tech
A study of the manner in which memory works turns up a surprising thing.
- Researchers have found that some basic words appear to be more memorable than others.
- Some faces are also easier to commit to memory.
- Scientists suggest that these words serve as semantic bridges when the brain is searching for a memory.
Cognitive psychologist Weizhen Xie (Zane) of the NIH's National Institute of Neurological Disorders and Stroke (NINDS) works with people who have intractable epilepsy, a form of the disorder that can't be controlled with medications. During research into the brain activity of patients, he and his colleagues discovered something odd about human memory: It appears that certain basic words are consistently more memorable than other basic words.
The research is published in Nature Human Behaviour.
An odd find
Image source: Tsekhmister/Shutterstock
Xie's team was re-analyzing memory tests of 30 epilepsy patients undertaken by Kareem Zaghloul of NINDS.
"Our goal is to find and eliminate the source of these harmful and debilitating seizures," Zaghloul said. "The monitoring period also provides a rare opportunity to record the neural activity that controls other parts of our lives. With the help of these patient volunteers we have been able to uncover some of the blueprints behind our memories."
Specifically, the participants were shown word pairs, such as "hand" and "apple." To better understand how the brain might remember such pairings, after a brief interval, participants were supplied one of the two words and asked to recall the other. Of the 300 words used in the tests, five of them proved to be five times more likely to be recalled: pig, tank, doll, pond, and door.
The scientists were perplexed that these words were so much more memorable than words like "cat," "street," "stair," "couch," and "cloud."
Intrigued, the researchers looked at a second data source from a word test taken by 2,623 healthy individuals via Amazon's Mechanical Turk and found essentially the same thing.
"We saw that some things — in this case, words — may be inherently easier for our brains to recall than others," Zaghloul said. That the Mechanical Turk results were so similar may "provide the strongest evidence to date that what we discovered about how the brain controls memory in this set of patients may also be true for people outside of the study."
Why understanding memory matters
Image source: Orawan Pattarawimonchai/Shutterstock
"Our memories play a fundamental role in who we are and how our brains work," Xie said. "However, one of the biggest challenges of studying memory is that people often remember the same things in different ways, making it difficult for researchers to compare people's performances on memory tests." He added that the search for some kind of unified theory of memory has been going on for over a century.
If a comprehensive understanding of the way memory works can be developed, the researchers say that "we can predict what people should remember in advance and understand how our brains do this, then we might be able to develop better ways to evaluate someone's overall brain health."
Image source: joob_in/Shutterstock
Xie's interest in this was piqued during a conversation with Wilma Bainbridge of University of Chicago at a Christmas party a couple of years ago. Bainbridge was, at the time, wrapping up a study of 1,000 volunteers that suggested certain faces are universally more memorable than others.
Bainbridge recalls, "Our exciting finding is that there are some images of people or places that are inherently memorable for all people, even though we have each seen different things in our lives. And if image memorability is so powerful, this means we can know in advance what people are likely to remember or forget."
Image source: Anatomography/Wikimedia
At first, the scientists suspected that the memorable words and faces were simply recalled more frequently and were thus easier to recall. They envisioned them as being akin to "highly trafficked spots connected to smaller spots representing the less memorable words." They developed a modeling program based on word frequencies found in books, new articles, and Wikipedia pages. Unfortunately, the model was unable to predict or duplicate the results they saw in their clinical experiments.
Eventually, the researchers came to suspect that the memorability of certain words was linked to the frequency with which the brain used them as semantic links between other memories, making them often-visited hubs in individuals's memory networks, and therefore places the brain jumped to early and often when retrieving memories. This idea was supported by observed activity in participants' anterior temporal lobe, a language center.
In epilepsy patients, these words were so frequently recalled that subjects often shouted them out even when they were incorrect responses to word-pair inquiries.
Modern search engines no longer simply look for raw words when resolving an inquiry: They also look for semantic — contextual and meaning — connections so that the results they present may better anticipate what it is you're looking for. Xie suggests something similar may be happening in the brain: "You know when you type words into a search engine, and it shows you a list of highly relevant guesses? It feels like the search engine is reading your mind. Well, our results suggest that the brains of the subjects in this study did something similar when they tried to recall a paired word, and we think that this may happen when we remember many of our past experiences."
He also notes that it may one day be possible to leverage individuals' apparently wired-in knowledge of their language as a fixed point against which to assess the health of their memory and brain.