Zhen Liu et al. in Nature
Zhen Liu et al. in Nature

Scientists Genetically Engineer Autistic Monkeys

Zhen Liu et al. in Nature
Zhen Liu et al. in Nature

Scientists in China have genetically altered monkeys to have a human gene associated with autism spectrum disorders. As a result, the monkeys show a range of symptoms associated with autism. Their findings were published today in the journal Nature.

Mutations of methyl-CpG binding protein 2 (MECP2) are found in 90 percent of patients with Rett syndrome, a severe developmental disorder affecting mostly girls that is classified as an autism spectrum disorder. MECP2 duplication syndrome, in which a person has multiple copies of the gene, also shares core symptoms with autism spectrum disorders. It mostly affects boys. The researchers inserted the MECP2 gene into oocytes, or egg cells, of Macaca fascicularis (known variously as the crab-eating macaque or cynomolgus monkey). After fertilization, 53 embryos were then transferred into 18 surrogate monkeys. Half became pregnant, and eight offspring were born. 

For the first year the monkeys were developmentally normal, but then issues began to appear. By about 18 months, "the first cohort of transgenic monkeys showed very similar behaviors related to human autism patients, including repetitive behaviors, increased anxiety, and most importantly, defects in social interactions," study co-author Zilong Qiu said in a press-only teleconference on January 21. The monkeys paced in circles around their cages and made a lot of anxious sounds, including grunts and screams. 

The researchers then used an "accelerated reproduction method" to produce a second generation of transgenic monkeys, which also showed defects in social interactions.

This genetic inheritance makes these transgenic monkeys "a very unique model for studying human autism," Qiu said.

Scientists generally use mice to study autism, but there are problems with that approach. For one thing, mice lack an area of the brain known as the prefrontal cortex, which is where some psychiatric disorders appear to be centered, MIT Technology Review notes.

"Mouse models have many advantages, such as low cost, the ability to generate large sample sizes and to carry out extensive pilot work quickly," Melissa Bauman, a researcher at the University of California who specializes in animal models of autism, said in a press statement to Nature. "However, given that Autism Spectrum Disorder (ASD) is [a] uniquely human disorder characterized by deficits in complex behaviors, there are limitations in relying solely on mouse models."

Another researcher cautioned that autism is an incredibly complex disease without a single underlying biological cause. "Some cases of autism do derive from relatively simple genetic events. Mutations in MECP2 and the duplication of MECP2 are only one of these myriad causes," said University of Mississippi Medical Center researcher Eric Vallender in another press statement. Vallender, who studies the neurogenetics of nonhuman primates (NHP), also noted that "repetitive motor behaviors and anxiety-like behaviors can be caused by many things, and 'decreased social interaction' is always tricky to both observe and quantify and to interpret.

"That said," he added, "they have created an excellent model of MECP2 duplication syndrome. This is not trivial and can be a major step forward for understanding neurodevelopmental disorders."

The researchers are currently conducting brain imaging studies of the MECP2 monkeys to try to identify the deficiency in the brain circuits that is responsible for autism-like behavior. Once they identify this brain circuit, they'll attempt to treat the monkeys using various methods, including more genetic modification: "We will use therapeutics, such as gene-editing tools like CRISPR-Cas9 … to explore the potential gene therapy," Qiu said. 

Meanwhile, the creation of transgenic NHPs raises ethical questions, as University of Toronto bioethicist Kerry Bowman told Gizmodo: “Transgenic NHP will potentially exhibit traits that are the most human-like; in turn this puts them at greater risk of research exploitation.”

nextArticle.image_alt|e
Mark Ralston, AFP/Getty Images
How a Hairdresser Found a Way to Fight Oil Spills With Hair Clippings
Mark Ralston, AFP/Getty Images
Mark Ralston, AFP/Getty Images

The Exxon Valdez oil tanker made global news in 1989 when it dumped millions of gallons of crude oil into the waters off Alaska's coast. As experts were figuring out the best ways to handle the ecological disaster, a hairdresser from Alabama named Phil McCroy was tinkering with ideas of his own. His solution, a stocking stuffed with hair clippings, was an early version of a clean-up method that's used at real oil spill sites today, according to Vox.

Hair booms are sock-like tubes stuffed with recycled hair, fur, and wool clippings. Hair naturally soaks up oil; most of the time it's sebum, an oil secreted from our sebaceous glands, but it will attract crude oil as well. When hair booms are dragged through waters slicked with oil, they sop up all of that pollution in a way that's gentle on the environment.

The same properties that make hair a great clean-up tool at spills are also what make animals vulnerable. Marine life that depends on clean fur to stay warm can die if their coats are stained with oil that's hard to wash off. Footage of an otter covered in oil was actually what inspired Phil McCroy to come up with his hair-based invention.

Check out the full story from Vox in the video below.

[h/t Vox]

nextArticle.image_alt|e
Bristly
A New Chew Toy Will Help Your Dog Brush Its Own Teeth
Bristly
Bristly

Few pet owners are willing to sit down and brush their pet's teeth on a regular basis. (Most of us can barely convince ourselves to floss our own teeth, after all.) Even fewer pets are willing to sit calmly and let it happen. But pet dental care matters: I’ve personally spent more than $1000 in the last few years dealing with the fact that my cat’s teeth are rotting out of her head.

For dog owners struggling to brush poor Fido’s teeth, there’s a slightly better option. Bristly, a product currently being funded on Kickstarter, is a chew toy that acts as a toothbrush. The rubber stick, which can be slathered with doggie toothpaste, is outfitted with bristles that brush your dog’s teeth as it plays.

A French bulldog chews on a Bristly toy.
Bristly

Designed so your dog can use it without you lifting a finger, it’s shaped like a little pogo stick, with a flattened base that allows dogs to stabilize it with their paws as they hack at the bristled stick with their teeth. The bristles are coated in a meat flavoring to encourage dogs to chew.

An estimated 80 percent of dogs over the age of 3 have some kind of dental disease, so the chances that your dog could use some extra dental attention is very high. In addition to staving off expensive vet bills, brushing your dog's teeth can improve their smelly breath.

Bristly comes in three sizes as well as in a heavy-duty version made for dogs who are prone to ripping through anything they can get their jaws around. A Bristly stick costs $29 and is scheduled to start shipping in October. Get it here.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios