Monthly Archives: July 2017

July 21, 2017 by Pierre Quvreux, The Conversation Credit: Tom/Flickr

Since 2012, genetic engineering has been revolutionised by CRISPR-Cas9 gene-editing. The technology is based on an enzyme from a bacterial cell, whose work is to cut the information storing system of living beings, DNA, at one predefined location. It generates a gap within the DNA. Then, a new sequence for example, a gene from another organism can be included.

Such a simple and inexpensive technology has made the creation of genetically modified organisms (GMOs) much easier. More interesting, including the gene of the Cas9 enzyme to the genome made the cell able to do by itself this cut-and-insert process. The technique, called "gene drive", can propagate a new gene in the whole population of organisms in a few generations. Once the introduced gene is installed in the population, one may call them GMOs. One of the most promising application would be to eradicate mosquitoes by spreading mutations that cause infertisity, but as explained in a 2017 article in the journal Nature, can be thwarted by evolution itself.

Arms race with bacteria

This is not the first time that evolution itself makes life hard for genetic engineering and biotechnology. One of the most important revolutions in human health was the industrial production of antibiotics. After World War II, western countries used them to fight human diseases but also to promote industrial agriculture and breeding. A basic rule of living beings' development is that species can ingest only a limited quantity of food and must face trade-offs between three main biologic functions: growth, reproduction and survival. This is true for domestic species as well but the existing trade-offs might not be to the liking of industries. Allocating more resources to one function inevitably leads to reduced performances of the other two.

Farmers had long before noticed that castrating young bulls turned them into steer that grew and fattened up faster. In the same way, the use of antibiotics decreased the stimulation of the immune system and enabled breeders to select fast-growing but less-resistant animals. Combined with industrial breeding relying on high densities of genetically similar individuals, the massive use of antibiotics is required to protect them against disease. In France, 40% of produced antibiotics are consumed by animals. Combined with the human consumption, bacteria have been exposed to a huge selective pressure or ways to survive antibiotics. Thus, many strains developed antibiotic resistances. Now, the emergence of multi-resistant infectious bacteria strains is a signficant concern in public health policies.

The fragility of homogeneity

A similar situation is observed in in agriculture. Increasing mechanisation and specialisation turned the landscape of polyculture windbreaks into endless fields of monoculture. Such a biomass of a few poorly genetically divers plants cultivars is a bonanza for pathogens and insects: if one gets infected, the next one is likely to be feeble too. In addition, crops were selected to have the highest yield, supported by a massive use of fertiliser and pesticides. Thus, the new cultivars are sensitive plants and poor competitors compared to weeds. The industrial agriculture was championed by GMOs, especially in North and South America. Crops producing toxins that killed caterpillars or were resistant to herbicide such as glyphosate were only efficient for a few years. Like bacteria, targeted insects and weeds evolved resistances in one or two decades.

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And the resilience of nature

By the same way, using the new CRISPR-Cas9 gene editing technology to modify or eliminate wild populations will not work forever and can also disturb the ecosystem. The large size of the targeted population, their short life cycle and the heavy selective pressure applied lead to huge adaptive advantages of resistant mutants that quickly spread in the population. Ecosystems are the outcome of billion years of evolution of complex networks of interacting species, thus building disease or pests managements technologies and policies without taking into account evolution must must fail in the long term.

Explore further: Gene drives likely to be foiled by rapid rise of resistance

Journal reference: Nature

Provided by: The Conversation

This article was originally published on The Conversation. Read the original article.

A study in fruit flies suggests that existing approaches to gene drives using CRISPR/Cas9, which aim to spread new genes within a natural population, will be derailed by the development of mutations that give resistance to ...

Scientists at UC Berkeley and UC Riverside have demonstrated a way to edit the genome of disease-carrying mosquitoes that brings us closer to suppressing them on a continental scale.

Researchers are exploring the use of the revolutionary gene-editing tool CRISPR-Cas9 to fight human disease and agricultural blight. But a study from Indiana University has found several challenges to the method's use in ...

A "gene drive" occurs when a specific gene is spread at an enhanced rate through an animal or plant population.

In recent years, scientists, clinicians and pharmaceutical companies have struggled to find new antibiotics or alternative strategies against multi-drug resistant bacteria that represent a serious public health problem. In ...

(Phys.org)A team of researchers affiliated with several institutions in South Korea has found a way to introduce an enzyme into a cell using the CRISPR technique without having to use a bacterial carrierthe result, ...

Three new species of toads have been discovered living in Nevada's Great Basin in an expansive survey of the 190,000 square mile ancient lake bottom. Discoveries of new amphibians are extremely rare in the United States with ...

(Phys.org)A large international team of researchers has conducted a genetic analysis and comparison of the world's biggest cats to learn more about their history. In their paper published on the open source site Science ...

Grasshopper mice (genus Onychomys), rodents known for their remarkably loud call, produce audible vocalizations in the same way that humans speak and wolves howl, according to new research published in Proceedings of the ...

Cutting through the ocean like a jet through the sky, giant bluefin tuna are built for performance, endurance and speed. Just as the fastest planes have carefully positioned wings and tail flaps to ensure precision maneuverability ...

Researchers at the University of California, Berkeley, have discovered how Cas1-Cas2, the proteins responsible for the ability of the CRISPR immune system in bacteria to adapt to new viral infections, identify the site in ...

Instead of having more children, a grandmother may pass on her genes more successfully by using her cognitive abilities to directly or indirectly aid her existing children and grandchildren. Such an advantage could have driven ...

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When evolution and biotechnologies collide - Phys.Org

Acorn ants are tiny. Theyre not the ants youd notice marching across your kitchen or swarming around sidewalk cracks, but the species is common across eastern North America. In particular, acorn ants live anywhere you find oak or hickory trees: both in forests and in the hearts of cities.

Cities are a microcosm of the changes that are occurring at a planetary scale on an urbanized Earth.

Thats why theyre so interesting to Sarah Diamond, a biology professor at Case Western Reserve University in Cleveland. Were comparing this little forest island within a city to traditional forest habitats, she says. Specifically, she and her colleagues are looking at how well city ants can tolerate higher temperatures compared to their rural cousins. The experiment is made possible by whats known as the urban heat island effect, which describes the tendency of the built-up infrastructure of cities think heat-absorbing concrete and asphalt, for example to create a hotter environment than less developed areas.

The urban island effect is several degrees Celsius warming as you go from rural habitats to urban habitats, Diamond says. A few degrees may not seem like a huge difference intuitively, but its on par with the amount global temperatures are expected to increase over the next decades.

The impact of climate change is something we cant simulate easily in natural ecosystems, but the artificial environment of cities may provide needed clues. We can take advantage of this unnatural experiment to see how organisms are responding to altered climatic regimes, Diamond says.

She and her team collected ant colonies from various sites in the city of Cleveland and in the surrounding countryside of Ohio. They then compared how colonies from each site adapted to the temperature conditions for both urban and rural environments. No matter how they mixed and matched temperatures, Diamond says, the urban ants always have higher heat tolerance, and they always lose their cold tolerance compared to the rural ants.

And because ants born in the lab only grow up in that environment, researchers have found that they seem to experience real genetic change, not just a shift in behavior, says Ryan Martin, one of Diamonds collaborators at Case Western. You can separate out those acclimatory effects, compared to those effects that are divergent between urban and rural ants [due to] genetic change. In other words, ants born from urban parents have higher tolerance to heat than ants born in rural environments, even when those newborn ant babies have never experienced the same conditions as their parents.

Diamond and her colleagues see the same effect in ants from places with measurably different climates, including Cincinnati, Ohio; Knoxville, Tennessee; and northern Florida. Theyre also expanding their research to include terrestrial isopods (the common critters known variously as pillbugs, sowbugs, and roly polies, among other names). The ultimate goal is to help answer a profound question: Can we predict how well some species will adapt to climate change based on how well they do in cities?

Cities do a lot more than generate heat, of course. They contaminate the soil and air, alter patterns of water drainage and sunlight exposure, radically increase noise pollution, and break up habitats. In the process, they routinely force plants, animals, and microbes to adapt or disappear. And studies have shown that the time scale for these environmental disruptions is astoundingly short compared with the usual rates of change in the natural world.

Cities are a microcosm of the changes that are occurring at a planetary scale on an urbanized Earth, says Marina Alberti, professor of urban design and planning at the University of Washington. Humans in cities are changing the rules of natures game. Empirical evidence is showing that we selectively determine which species can live in cities and cause organisms to undergo rapid evolutionary change.

A number of researchers have become interested in urban ecology because of those relatively fast changes. Most North American cities are less than a century or two old, and the number of humans living in cities has jumped dramatically over the last 100 years. Even though thats a blink of an eye compared with the history of Earth, eco-evolutionists like Diamond are finding a wealth of measurable differences between urban organisms and members of the same species living in undeveloped ecosystems. Their experiments are beginning to reveal how quickly evolution can act under pressure.

Charles Darwin began On the Origin of Species by talking about artificial selection: how humans have bred animals and plants to bring out some features and suppress others. Any number of species have been domesticated, from dogs to pigeons to corn, changing from their wild form into something different. Artificial selection can be extremely rapid, simply by controlling how domesticated species reproduce.

Urban evolution, on the other hand, is still controlled by natural selection. What separates it from normal natural selection is that humans are the indirect source of the selection pressures. Our actions restrict nesting spaces by chopping down trees, paving over places for plants to sprout, and driving out some predators while bringing in new ones like cats and dogs. And of course, we raise temperatures by replacing vegetation with concrete, building with heat-absorbing roofs, and introducing greenhouse gases such as ozone from engines.

Our findings of rapid change of many plants and animals demonstrates the power of natural selection even in our cities, says Alberti. Many species will continue to go extinct, but we show that others are evolving the necessary strategies and physical characteristics to coexist with humanity. Understanding the role we play in planetary eco-evolution will provide us with the information to make better decisions and build more sustainable urban settlements.

But how large and rapid are these changes? And how can we separate fundamental changes in organisms makeup due to evolution from behavioral shifts? For instance, city ants havent evolved into a distinct species from country ants, even if they still exhibit measurable genetic shifts. Urban-dwelling birds, on the other hand, sing at higher pitches to be heard over the noises of the city. But its unclear if that behavior is a genetic change, or if their offspring would resume normal levels of singing if they were raised in the country.

In a recent study in the Proceedings of the National Academy of Sciences, Alberti and her colleagues found more than 1,600 cases from around the world in which urbanization has produced measurable evolutionary effects. Those effects include changes in the size of seeds or offspring, what kinds of food animals eat and where they nest, and how species interact with each other. The cases include plants, invertebrates (insects and so forth), and a range of vertebrates, from fish to birds.

Because of rapid urbanization, these changes occurred on the scale of centuries or less. By showing the genetic differences between urban and rural acorn ants, Diamonds experiments in Cleveland revealed that the shift must have occurred since the city began its modern period of growth. Thats roughly 100 years, or about 20 generations of acorn ant queens. And the shift might have been even faster, since were only seeing the end result, not the incremental changes since Cleveland began to change into a modern city.

Andrew Hendry of McGill University, one of Albertis coauthors on the recent study, says he suspected that the urban heat island effect is less significant than other problems city-dwelling organisms face, such as habitat loss or the breaking up of habitats into small discontinuous pieces. Even so, he added, that doesnt mean temperature isnt an important factor: When it comes to specific things the temperatures affecting, it can give us some guidelines about how fast can things evolve, what types of organisms can evolve faster or slower, or respond strongly or weakly in respect to temperature.

In other words, an organism that evolves rapidly in the city might do better in general when trying to adapt to a warming world. All the weedy, invasive species, like cabbage white butterflies, are doing fine, Diamond says. Thats little consolation, though. Just as cities contain a shadow of the biodiversity of the rural landscape they replace, climate change could result in a cascade of species loss.

Just as cities contain a shadow of the areas former biodiversity, climate change could result in a cascade of species loss.

What you find is urban populations have lower [genetic variation], says Martin. Presumably, that means theyve used up some of that variation in evolving, but it also might mean theyve lost some of their ability to respond [to environmental changes].

Diamonds ant lab is dominated by a row of environmental growth chambers. They resemble refrigerators, but their interiors can run the temperature gamut from hot summer days to cold winter nights. She opened one and presented a cup designed to hold urine samples, familiar to anyone who has undergone medical or drug tests. No ones peeing in these, she says. Were putting acorn ants in them.

Inside the cup was an entire living colony of ants crawling around their acorn nest. Each insect is smaller than one eighth of an inch long, with a body so light orange-brown in color it is almost invisible against the acorn. Acorn ant colonies usually have fewer than 100 tiny workers, which explains how they can all fit into a single nut resting in the cup.

Most species arent as easy to study as acorn ants. Theyre either too big, reproduce too slowly, or dont survive well under lab conditions. However, by focusing on these tiny creatures and how they survive in living urban laboratories, we may be starting to understand how vulnerable all species are in the uncontrolled experiment known as climate change.

Matthew R. Francis is a physicist, science writer, public speaker, educator, and frequent wearer of jaunty hats. He blogs at Galileos Pendulum.

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What City Ants Can Teach Us About Species Evolution And Climate Change - Undark Magazine

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A visual journey through the evolution of the influencer Mashable That's the tension today's social media celebrities have created. And it's not just marketers, brands, and stars who feel confused. It's everyday customers as well. Especially when it comes to who to trust. In a sense, there's nothing new about ...

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A visual journey through the evolution of the influencer - Mashable

The Carolina Panthers open training camp on July 26 at Wofford College in Spartanburg, South Carolina. Heres a closer look at the Panthers' camp:

Top storyline: As quarterback Cam Newton goes, so go the Panthers. When Newton had an MVP season in 2015, the Panthers went to the Super Bowl. When he had statistically the worst season of his career in 2016, the team struggled and missed the playoffs after capturing three consecutive NFC South titles. Newton had offseason surgery to fix a partially torn rotator cuff, so training camp will be the first big test to see if the problem has been corrected. The Panthers added more weapons in first- and second-round draft picks Christian McCaffrey and Curtis Samuel. Their presence will give the 6-foot-5 quarterback more opportunities to get rid of the ball quicker and take fewer hits ... and to give him fewer reasons to run. Its an evolution for Newton and the offense, and how well that adaptation process goes will largely determine how well the Panthers do this season.

QB depth chart: Newton is coming off shoulder surgery, and the Panthers want their franchise quarterback to run less in order to safeguard his long-term health. Beyond that, nothing has changed from the past three seasons. Derek Anderson remains entrenched as the veteran and capable backup. Joe Webb is back as a third quarterback/wide receiver/special-teams player.

Bubble watch: The message that place-kicker Graham Gano needed to step up came on the third day of the draft, when the Panthers selected Harrison Butker out of Georgia Tech in the seventh round. It was the first time the Panthers drafted a place-kicker. Gano missed several big kicks that had a drastic impact on last seasons 6-10 record, and he made just 78.9 percent of his field goals.

That rookie could start: Taylor Moton. The second-round pick out of Western Michigan might be a long shot to start at right tackle, but with the future of Michael Oher uncertain and 2015 fourth-round pick Daryl Williams still somewhat unproven, Moton might get an opportunity. He impressed coaches during offseason workouts with his ability to play right and left tackle. Moton could be a year away, but if he impresses when the pads are on, hell have a chance to start now.

Kelvin Benjamin's weight: Much, probably too much, was made of the 6-foot-5 wide receiver being overweight at the start of offseason workouts. The last time that happened was two years ago, and Benjamin reported to training camp in the best shape of his career. He was arguably the MVP of that 2015 camp before suffering a season-ending knee injury. If Benjamin can return to that form and be pushed by the other receiving weapons the Panthers have added, he could be in for a big season.

Contract issues: In 2016, Greg Olsen became the first tight end in NFL history to record three consecutive seasons with 1,000 receiving yards. He wants a restructured deal to reflect that accomplishment, even though his current contract doesnt expire until after the 2018 season. Outside linebacker Thomas Davis, 34, entering the final year of his deal, also would like an extension. These are two key players and leaders, so look for the front office to do all it can to keep them happy.

For daily updates at camp, check out the Carolina Panthers clubhouse page.

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Evolution of Cam Newton, offense focus for Carolina Panthers in ... - ESPN (blog)

Metro-Goldwyn-Mayer is buying the assets of Evolution Media and rolling them into MGMs television division led by Mark Burnett, president of the Television Group & Digital.

Terms of the deal were not disclosed. Founder and CEO Douglas Ross will be president of the acquired business and Alex Baskin, executive vice president of programming anddevelopment, will become Evolutions president of programming and development.

Evolution Media produced series including The Real Housewives of Orange County, The Real Housewives of Beverly Hills and Vanderpump Rules for Bravo, as well as other series for E! network, CBS, NBC and Disney Channel.

Those productions will join MGM Televisions current series including Survivor (CBS), The Voice (NBC), Shark Tank (ABC), Jamie Foxxs Beat Shazam (FOX) and Steve Harveys FUNDERDOME (ABC), along with scripted series Fargo (FX), The Handmaids Tale (Hulu), Vikings (HISTORY) and the upcoming Get Shorty (EPIX).

Doug and Alex have been creating and producing hit series for decades. These guys have talent and drive and will help our MGM Television hit machine to continue to grow and grow, said Burnett in a statement.

After 30 years of being fiercely independent, we couldnt be more proud and excited to join forces with the dynamic, creative and supportive leadership team at MGM. We look forward to working with Gary, Mark and Barry to supercharge Evolution and to write the next chapters in the companys history with them, said Ross in a statement.

RELATED: MGM to spend more than $1B to buy out Viacom and Lionsgate in Epix acquisition

Earlier this year, MGM dropped about $1 billion to buy the whole of Epix from co-owners Viacom and Lionsgate.

"The addition of EPIX provides MGM with a premier distribution platform that complements our strong stable of new and library content in both film and television. The acquisition creates increased revenue diversity, new opportunities for growth, and earnings accretion for the benefit of stockholders," said Gary Barber, chairman and CEO of MGM, in a statement.

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MGM acquires 'Real Housewives' studio Evolution Media - FierceCable