Your Beloved Pet Is Old. Should You Clone It?
Melvin was a special dog. A mixture of Catahoula and Doberman with black and tan markings, he was the office greeter, barking hellos to everyone who visited the Dupont Veterinary Clinic in Lafayette, Louisiana, which is owned by his human companions, Dr. Phillip Dupont and his wife, Paula. The couple say he's the best dog they ever owned.
When Melvin passed away, having two identical replicas helped ease the couple's grief.
He seemed to have an uncanny knack for understanding what they were saying, he could find lost car keys in tall grasses and the Duponts trusted him so much they felt comfortable having him babysit their grandson unattended in the backyard.
So when the 75-pound canine turned 9 and began to show signs of age, the Duponts sent off some of his skin cells to a lab in South Korea, the Sooam Biotech Research Foundation, to have him cloned. The Duponts toured the South Korean facilities and were satisfied that the animals were being treated well. While the first cloned puppy died from distemper, the second attempt produced two healthy animals—which the couple named Ken and Henry. When Melvin did pass away nearly two years later, in 2014, having two identical replicas helped ease the couple's grief. Even though it cost about $70,000 to clone Melvin, it was well worth it. "Melvin gave us a lot of pleasure," says Paula Dupont, "and this was less than the price of a new Land Cruiser."
As the technology improves, costs will tumble, making pet cloning more affordable for the mainstream.
The news has been filled recently with stories of celebrities such as Barbra Streisand or billionaire Barry Diller and his fashion icon wife, Diane von Furstenberg, spending big bucks to preserve their beloved pets—a practice New York magazine called "a laughable, extravagant waste of money." But cloning Fido isn't just for the ultra-wealthy anymore. Texas-based ViaGen now offers a domestic cloning service that will replicate Lassie for $50,000 and Garfield's kittens for a mere $25,000. While the exact number of cloned pets isn't known, the South Korean company says it has cloned about 800 pets while ViaGen has cloned about 100 cats and dogs. And as the technology improves, costs will tumble, making it more affordable for the mainstream, says Ron Gillespie, who heads PerPETuate, a Massachusetts-based outfit that collects and cryo preserves pet DNA, and works closely with ViaGen.
Even if the animals are genetic twins, biologists say, there are no guarantees their personalities will match, too.
While replicating Fido is becoming more feasible, should you? Animal rights organizations like The Humane Society and PETA are sharply critical of the practice, which is largely unregulated, and think it's outrageous to spend $50,000 or more to preserve Fluffy's genetic makeup when millions of cats and dogs are languishing in shelters and millions more are euthanized every year. And even if the animals are genetic twins, biologists say, there are no guarantees their personalities will match, too. Like humans, dogs' personalities are influenced by their environment and there are always variations in how the genes are expressed--although the Duponts say that Ken and Henry seem more like Melvin every day. "Their personalities are identical," says Paula.
Clones Ken and Henry, with Dr. Dupont and 10-year-old Melvin. Though all three dogs are genetic twins, their markings differ because the environment can influence how genes are expressed.
Still, the loss of a beloved pet can be incredibly painful, and in some cases, cloning can help deal with deep psychological wounds. When Monni Must's daughter died suddenly at age 28, the Michigan-based photographer adopted her child's black Lab, Billy Bean. As the dog got older and frailer, Must realized she couldn't handle losing her last link to her daughter—so she ponied up $50,000 to have the animal cloned. "I knew that I was falling apart," Must told Agence France-Presse. "The thought of Billy dying was just more than I could handle."
But these heated disputes miss what bioethicists believe is the real ethical dilemma—the fate of the female animals that provide the eggs and gestate the cloned puppies. "This issue tends to get framed as 'it's their personal choice, it's their money and they can do what they want with it,'" says Jessica Pierce, a bioethicist and author of Run, Spot, Run: The Ethics of Keeping Pets. "But this whole enterprise has all this collateral damage and behind-the-scenes impacts that people ignore. No one is talking about the dogs who are sacrificing themselves for this indulgence, and are suffering and being tormented just to have your clone."
"Even in the best-case scenarios, the cloned pet may go through several rounds of failed reproductive attempts—failed pregnancies, still births, and deformities."
Animal cloning, of course, is not new. Dolly, the sheep, made her debut in 1996 as the first cloned mammal. In 2005, Korea's Sooam Biotech cloned the first dog, and cloning horses and cows has become almost routine. Typically, the cloning process for dogs is fairly uncomplicated. It entails the use of a group of female dogs whose hormones are artificially manipulated with drugs to promote them to produce eggs. The eggs are then surgically harvested from donor dogs' ovaries. The immature eggs are stripped of their genetic information and then the pet's DNA is fused with the egg. When the embryo begins to develop, it is then transplanted to the womb of a surrogate dog.
However, cloning can have a high failure rate. When South Korea's Sooam Biotech lab cloned the first dog in 2005, there were 1000 failures—which means that number of eggs were fertilized and began to gestate, but at some point their development failed. And this figure doesn't include the number of dogs born with deformities serious enough that they are incompatible with life and need to be euthanized. "Even in the best-case scenarios, the cloned pet may go through several rounds of failed reproductive attempts—failed pregnancies, still births, and deformities," says Insoo Hyun, a bioethicist at Case Western Reserve University in Cleveland. "You can't do just one egg and one transfer. That won't happen. There is no guarantee that the very first time you will have a healthy animal. They're not miracle workers and you can't fight biology."
"You just have to let your pet go. It's all part of the experience."
But Ron Gillespie, who's been in the animal breeding business for decades, thinks these fears are overblown and that cloning is similar to the selective breeding that goes on all the time with cattle and even with champion racehorses. "We're really the victim of a lot of misinformation and misunderstanding," he says. "Right now, on average, we're dealing with three dogs: two that supply eggs and one to carry the embryo to term."
Still, this debate skirts the hard realities: dogs and cats simply have shorter lifespans than humans, and ethicists and animal rights activists believe there are better ways to deal with that grief. "You just have to let your pet go," says Hyun. "It's all part of the experience."
Gene Transfer Leads to Longer Life and Healthspan
The naked mole rat won’t win any beauty contests, but it could possibly win in the talent category. Its superpower: fighting the aging process to live several times longer than other animals its size, in a state of youthful vigor.
It’s believed that naked mole rats experience all the normal processes of wear and tear over their lifespan, but that they’re exceptionally good at repairing the damage from oxygen free radicals and the DNA errors that accumulate over time. Even though they possess genes that make them vulnerable to cancer, they rarely develop the disease, or any other age-related disease, for that matter. Naked mole rats are known to live for over 40 years without any signs of aging, whereas mice live on average about two years and are highly prone to cancer.
Now, these remarkable animals may be able to share their superpower with other species. In August, a study provided what may be the first proof-of-principle that genetic material transferred from one species can increase both longevity and healthspan in a recipient animal.
There are several theories to explain the naked mole rat’s longevity, but the one explored in the study, published in Nature, is based on the abundance of large-molecule high-molecular mass hyaluronic acid (HMM-HA).
A small molecule version of hyaluronic acid is commonly added to skin moisturizers and cosmetics that are marketed as ways to keep skin youthful, but this version, just applied to the skin, won’t have a dramatic anti-aging effect. The naked mole rat has an abundance of the much-larger molecule, HMM-HA, in the chemical-rich solution between cells throughout its body. But does the HMM-HA actually govern the extraordinary longevity and healthspan of the naked mole rat?
To answer this question, Dr. Vera Gorbunova, a professor of biology and oncology at the University of Rochester, and her team created a mouse model containing the naked mole rat gene hyaluronic acid synthase 2, or nmrHas2. It turned out that the mice receiving this gene during their early developmental stage also expressed HMM-HA.
The researchers found that the effects of the HMM-HA molecule in the mice were marked and diverse, exceeding the expectations of the study’s co-authors. High-molecular mass hyaluronic acid was more abundant in kidneys, muscles and other organs of the Has2 mice compared to control mice.
In addition, the altered mice had a much lower incidence of cancer. Seventy percent of the control mice eventually developed cancer, compared to only 57 percent of the altered mice, even after several techniques were used to induce the disease. The biggest difference occurred in the oldest mice, where the cancer incidence for the Has2 mice and the controls was 47 percent and 83 percent, respectively.
With regard to longevity, Has2 males increased their lifespan by more than 16 percent and the females added 9 percent. “Somehow the effect is much more pronounced in male mice, and we don’t have a perfect answer as to why,” says Dr. Gorbunova. Another improvement was in the healthspan of the altered mice: the number of years they spent in a state of relative youth. There’s a frailty index for mice, which includes body weight, mobility, grip strength, vision and hearing, in addition to overall conditions such as the health of the coat and body temperature. The Has2 mice scored lower in frailty than the controls by all measures. They also performed better in tests of locomotion and coordination, and in bone density.
Gorbunova’s results show that a gene artificially transferred from one species can have a beneficial effect on another species for longevity, something that had never been demonstrated before. This finding is “quite spectacular,” said Steven Austad, a biologist at the University of Alabama at Birmingham, who was not involved in the study.
Just as in lifespan, the effects in various organs and systems varied between the sexes, a common occurrence in longevity research, according to Austad, who authored the book Methuselah’s Zoo and specializes in the biological differences between species. “We have ten drugs that we can give to mice to make them live longer,” he says, “and all of them work better in one sex than in the other.” This suggests that more attention needs to be paid to the different effects of anti-aging strategies between the sexes, as well as gender differences in healthspan.
According to the study authors, the HMM-HA molecule delivered these benefits by reducing inflammation and senescence (cell dysfunction and death). The molecule also caused a variety of other benefits, including an upregulation of genes involved in the function of mitochondria, the powerhouses of the cells. These mechanisms are implicated in the aging process, and in human disease. In humans, virtually all noncommunicable diseases entail an acceleration of the aging process.
So, would the gene that creates HMM-HA have similar benefits for longevity in humans? “We think about these questions a lot,” Gorbunova says. “It’s been done by injections in certain patients, but it has a local effect in the treatment of organs affected by disease,” which could offer some benefits, she added.
“Mice are very short-lived and cancer-prone, and the effects are small,” says Steven Austad, a biologist at the University of Alabama at Birmingham. “But they did live longer and stay healthy longer, which is remarkable.”
As for a gene therapy to introduce the nmrHas2 gene into humans to obtain a global result, she’s skeptical because of the complexity involved. Gorbunova notes that there are potential dangers in introducing an animal gene into humans, such as immune responses or allergic reactions.
Austad is equally cautious about a gene therapy. “What this study says is that you can take something a species does well and transfer at least some of that into a new species. It opens up the way, but you may need to transfer six or eight or ten genes into a human” to get the large effect desired. Humans are much more complex and contain many more genes than mice, and all systems in a biological organism are intricately connected. One naked mole rat gene may not make a big difference when it interacts with human genes, metabolism and physiology.
Still, Austad thinks the possibilities are tantalizing. “Mice are very short-lived and cancer-prone, and the effects are small,” he says. “But they did live longer and stay healthy longer, which is remarkable.”
As for further research, says Austad, “The first place to look is the skin” to see if the nmrHas2 gene and the HMM-HA it produces can reduce the chance of cancer. Austad added that it would be straightforward to use the gene to try to prevent cancer in skin cells in a dish to see if it prevents cancer. It would not be hard to do. “We don’t know of any downsides to hyaluronic acid in skin, because it’s already used in skin products, and you could look at this fairly quickly.”
“Aging mechanisms evolved over a long time,” says Gorbunova, “so in aging there are multiple mechanisms working together that affect each other.” All of these processes could play a part and almost certainly differ from one species to the next.
“HMM-HA molecules are large, but we’re now looking for a small-molecule drug that would slow it’s breakdown,” she says. “And we’re looking for inhibitors, now being tested in mice, that would hinder the breakdown of hyaluronic acid.” Gorbunova has found a natural, plant-based product that acts as an inhibitor and could potentially be taken as a supplement. Ultimately, though, she thinks that drug development will be the safest and most effective approach to delivering HMM-HA for anti-aging.
In recent years, researchers of Alzheimer’s have made progress in figuring out the complex factors that lead to the disease. Yet, the root cause, or causes, of Alzheimer’s are still pretty much a mystery.
In fact, many people get Alzheimer’s even though they lack the gene variant we know can play a role in the disease. This is a critical knowledge gap for research to address because the vast majority of Alzheimer’s patients don’t have this variant.
A new study provides key insights into what’s causing the disease. The research, published in Nature Communications, points to a breakdown over time in the brain’s system for clearing waste, an issue that seems to happen in some people as they get older.
Michael Glickman, a biologist at Technion – Israel Institute of Technology, helped lead this research. I asked him to tell me about his approach to studying how this breakdown occurs in the brain, and how he tested a treatment that has potential to fix the problem at its earliest stages.
Dr. Michael Glickman is internationally renowned for his research on the ubiquitin-proteasome system (UPS), the brain's system for clearing the waste that is involved in diseases such as Huntington's, Alzheimer's, and Parkinson's. He is the head of the Lab for Protein Characterization in the Faculty of Biology at the Technion – Israel Institute of Technology. In the lab, Michael and his team focus on protein recycling and the ubiquitin-proteasome system, which protects against serious diseases like Alzheimer’s, Parkinson’s, cystic fibrosis, and diabetes. After earning his PhD at the University of California at Berkeley in 1994, Michael joined the Technion as a Senior Lecturer in 1998 and has served as a full professor since 2009.
Dr. Michael Glickman