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Just Like Dolly: Scientists Clone 2 Monkeys

Zhong Zhong peeks around a stuffed toy. (Credit: Qiang Sun and Mu-ming Poo / Chinese Academy of Sciences)

The world recently welcomed a pair of monkeys that were created using the same method used to clone Dolly the sheep.

In a study published Wednesday in Cell, researchers successfully produced two genetically identical, long-tailed crab-eating macaques. Zhong Zhong and Hua Hua were born eight and six weeks ago, respectively, at the Chinese Academy of Sciences Institute of Neuroscience in Shanghai. It’s a technical benchmark that could have future applications in clinical research.

Species closer to humans, such as these old-world monkeys, are more helpful when it comes to studying primate physiological functions. These crab-eating macaques are the most commonly used non-human primate because they are widespread and not endangered, according to Dr. Muming Poo, an author of the study. The ability to create and tailor various populations of genetically uniform monkeys with which to conduct research can be useful in testing out new therapeutic treatments or studying disease progression in real models with minimal individual variation.

“In principle, it can be applied to humans, “ says Poo.

However, he and his fellow researchers are focused on producing animal models that are useful for medicine and human health, especially with genetic-based diseases. Plenty of neurodegenerative diseases have a genetic basis, and Poo is currently using his animal models to target Huntington’s disease. His approach could be further applied in autism or immunodeficiency research.

Although Zhong Zhong and Hua Hua aren’t the first monkey clones ever, they are the first ones to be made using somatic cell nuclear transfer (SCNT), which has been successfully applied in 23 mammalian species including mice, cats and dogs. In this process, the nucleus is removed from a healthy egg cell and replaced with one from another cell. In the end, the newly developed animal is an exact genetic copy of the animal that donated the cell nucleus.

And here's Hua Hua. (Credit: Qiang Sun and Mu-ming Poo / Chinese Academy of Sciences)

And here’s Hua Hua. (Credit: Qiang Sun and Mu-ming Poo / Chinese Academy of Sciences)

“It’s possible that even though the DNA sequences are the same between the clones, from different mother surrogates, they may produce different epigenetic modulations, especially after birth,” says Poo.

In Zhong Zhong and Hua Hua’s cases, fetal fibroblast nuclei were transplanted into the egg cell. The egg cell was then implanted into a surrogate mother, who then live birthed the newborn.

In addition to Zhong Zhong and Hua Hua, another pair of monkey clones was borne from an adult body cell nuclei transfer, but they did not live long after birth. Poo suspects that adult body cells are harder to reprogram, or perhaps it was simply a numbers issue—if there were a greater sample size, there would be more healthy newborns.

Right now, it takes nine months to produce one generation of clones, said study co-author Qiang Sun, who claims that they can now receive two live offspring from six starter monkeys. They have not yet exhausted different modulation possibilities to yield the highest reproduction efficiency, but their goal is to make it so that as few as possible monkeys need to be used in the process.

Zhong Zhong and Hua Hua are living together in an incubator designed for human babies. Their behaviors and health are monitored daily, and when they are old enough they’ll be subjected to brain scans to check if their neurological developments are also similar.

“They live in the same environment, eat the same food, and are taken care of by the same person,” says Sun.

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A Functioning Fake Womb

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Chemicals in Non-Stick Pans May Contribute to Weight Gain

Uhoh: Those non-stick pans you love cooking with are often made with a chemical that could contribute to weight gain. (Credit: Shutterstock)

More than 38 percent of American adults and 17 percent of American children are obese. And while there are numerous ways to shed pounds, it’s often difficult for many people to keep them off. It turns out some common items regularly used by people across the world could be the culprit.

A study released Tuesday in PLOS Medicine suggests that perfluoroalkyl substances (PFASs) could be contributing to weight gain and lead to obesity. Since the 1950s, these environmental chemicals have been used in food packaging, non-stick cookware, stain resistant fabrics and carpets, water-repellent clothing, and even some cosmetics. These manmade compounds’ effects on humans aren’t well known, but past studies on animals have shown they may disrupt the endocrine system, or the collection of glands that produce hormones. PFASs have also been linked to cancer, immune issues and high cholesterol.

Down and Up

Over the course of two years, researchers put 621 obese and overweight men and women on energy-restricted diets and tracked their weights. Measuring the plasma concentrations of PFASs, they were able to gather metabolic information including body weight and resting metabolic rate (RMR).

Researchers found that those with higher levels of PFASs at the beginning of the experiment were associated with regaining the pounds they lost, especially in women. Participants lost on average 14 pounds (6.4 kg) in the first six months, regaining almost half of the weight throughout the study. The weight gain could be due to a decline of RMR over the first six months.

“These chemicals may lead to more rapid weight gain after dieting,” Qi Sun, co-author of the study, told the Guardian. “It is very hard to avoid exposure to PFASs, but we should try to. It’s an increasing public health issue.”

With that said, the authors can’t definitively link PFAS chemicals to the weight regain. Some potentially important influences weren’t measured including socioeconomic and psychosocial factors and potential relapses to prior diets weren’t considered. Still, the authors hope this study will lead to further research of environmental chemicals and their possible impact on obesity.

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