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Tag: genes

Reflections on the dog paddle

dogpaddle

Throw a dog who has never gone swimming into a pool and, pretty much instantly, he’ll start moving his four legs in a series of motions we’ve come to call the dog paddle.

Throw a human who has never gone swimming into a pool and — though the possibilities are much higher for helpless flailing about, cussing, drowning, or becoming traumatized for life — he may eventually come to his senses enough to try and work his way back to the side of the pool. He’ll do so not using a butterfly stroke, breast stroke or Australian crawl, but by doing what dogs do.

The dog paddle: It’s seemingly instinctual. It’s primitive. And though we humans mostly outgrow it, it remains sort of the default mode of propelling ourselves through water.

Just how primitive it may be is under investigation by Dr. Frank Fish, a professor of biology at West Chester University who — maybe because of his name, maybe not — has spent most of his career studying how marine mammals swim.

Most recently, he has been studying the swimming motions of dogs, and he has concluded that they are very similar to the motions dogs use in trotting. That explains the  ease with which most dogs can make the transition from land to water — requiring no lessons, and (generally) little coaxing: They basically propel themselves the same way in water as they do on land.

That their stride and strokes are nearly identical is interesting in itself, but Fish thinks it could also help explain how whales and dolphins ended up in the ocean.

Fish subscribes to the theory that marine mammals were intitially four-legged land dwellers who ventured into the water one day (likely dog paddling at first), decided they liked it better there, then evolved into such super swimmers that they no longer needed legs, or, for that matter, land.

underwater dogsFor his research, Fish set up some underwater video cameras and enlisted eight volunteer dogs (including his own) of six different breeds, ranging from Yorkshire terrier to Newfoundland.

He borrowed a swimming pool used to rehabilitate horses at the University of Pennsylvania.

Analyzing the video, Fish and fellow researchers saw that dogs swim much like they run — with diagonal pairs of legs churning in unison, according to Science Daily. Fish presented his findings at the 2014 Society for Integrative and Comparative Biology (SICB) meeting in Austin.

While there’s plenty of dog research we’d categorize as a silly waste of time, we find all this pretty intriguing.

First, it reminds us that practice makes perfect — to think that long, long ago there might have been a couple of four-legged dolphins who didn’t know how to swim, hesitating at the edge of the water: “I dunno, it looks dangerous … should we go in?”

Second, in an era when we’re increasingly relying on computers to do our thinking for us, it serves as a warning that those muscles we don’t use can disappear. It raises a host of interesting questions about our future, and our past.

Why is it we humans tend to dog paddle in our first encounters with water? Is that some sort of instinctual nod to a past when we got about on four legs, instead of two?

If cavemen had spent more time at the swimming hole, might we homo sapiens have evolved into something more amphibious?

Given that, might mermaids really exist?

It’s kind of inspiring to think there might have been a day when dolphins, the planet’s most graceful swimmers, were total klutzes in the water — that they started off splashing about with some awkward looking dog paddling and progressed to the point where they could actually leap out of the water.

It reminds us that, maybe, anything is possible with enough hard work — even when it comes to behaviors we might think are genetic and therefore unchangeable. Do we sometimes wear our genes too tightly, and allow them to restrict us from leaping into new things, and getting over old ones?

We wish Fish luck in unraveling how four-legged terrestrial forms evolved into no-legged, finned ones. And as long as the dogs involved in his research are having a good time –  given Fish is letting his own dog be used in the study, we assume they are – we have no problem with them helping the professor prove his point.

In other words: Go Fish!

(Top Photo, Society for Integrative and Comparative Biology; bottom photo, from the book Underwater Dogs)

Laboratory use of dogs on the upswing

Given the endlessly rising popularity of dogs, and our increasing emotional attachment to them, medical researchers who use them for experiments can expect stronger and growing opposition to the practice from the public, a leading expert in canine-human interaction told a conference at Johns Hopkins University this week.

James Serpell, director of the Center for the Interaction of Animals and Society at the University of Pennsylvania School of Veterinary Medicine, was the keynote speaker at a conference sponsored by the Center for Alternatives to Animal Testing at the Bloomberg School of Public Health.

The 30-year-old, non–profit center promotes humane science by supporting the creation, development and use of alternatives to animals in research, product safety testing, and education. It seeks ways to replace animals with non-animal methods, reduce the numbers of animals necessary, or refine methods to make them less painful or stressful to the animals involved

Serpell and other speakers both pointed out that after decades of declining, the use of dogs in medical research has increased in the last couple of years.

U.S. Department of Agriculture figures show that the number of dogs used in medical research and testing dropped from 200,000 in 1973 to 66,000 in 2007, said Tanya Burkholder, chief of the Small Animal Section at the National Institutes of Health. Now, she said, the number has risen to about 75,000 a year.

Much of the increase is likely a result of advancements in, and the promise of, gene therapy.

Ivan Pavlov

Dogs have always been a valuable research model for scientists, going as far back as Aristotle’s day. Their size, physiology and cooperative behavior have made them convenient models for scientists, who, like Pavlov’s dog, grew conditioned to using them in experiments.

While public opposition to subjecting dogs to medical experiments resulted in the practice dwindling in recent decades, the use of dogs has crept up again in the last two years due to advances in molecular biology, genetics and the sequencing of the canine genome.

Because dogs get about 220 of the same inherited diseases and disorders that humans do — including Alzheimer’s, muscular dystrophy, hemophilia and retinal degeneration – medical researchers are able to study the underlying genetic defects and, through dogs, seek cures.

This means dogs are being bred to be born with the diseases in colonies at U.S. universities and research institutes and, in the case of South Korea, cloned to be born with the diseases.

No one at the conference went so far as to suggest a halt to using dogs in research, but Serpell warned that the practice does come with risks, and a price.

Dogs evoke protective and nurturing instincts in people, and those have grown stronger as the dog-human relationship has evolved — to the point that dogs are viewed more as family members than family pets. Public opposition to the laboratory use of dogs has continually grown in the last few decades.

Researchers need to be cognizant not just of society’s strong feelings about dogs, but also about dog’s strong feelings for humans, Serpell said.  “Many dogs undergo severe distress when contact with a human is limited or thwarted. We don’t give that regard sufficient credence,” he said.

The stronger attachment to dogs is in part due to breeders focusing on creating animals for purposes of human companionship, unlike in the past when they were bred for the work they could do. Serpell noted that baby-like features, for one thing, appeal to humans.

Showing photos of dogs, Serpell pointed to one and said, “This animal looks like it was invented by Walt Disney.”

Our attraction to dogs stems too from the fact that they make eye contact with humans more than any other species, and studies have shown that petting, or even looking, at a dog increases our levels of oxytocin.

“These dogs are turning us on by looking at us,” he said.

Our evolving closeness to dogs has implications for the laboratory, he noted, and perhaps all of society.

Serpell pointed to commentator Tucker Carlson’s recent statement that dogs are the social equals of humans, and that therefore Micheal Vick should have been executed for killing them.

“Lots of people feel the same way,” he said.

Tiger Woods has nothing on Yogi

YogiStep aside Tiger Woods, Jesse James, even Wilt Chamberlain. You’ve got nothing on Yogi, the Hungarian vizsla who won best in show at Britain’s prestigious Crufts competition this year.

The  champion Aussie show dog has fathered 525 puppies  in the five years since he emigrated to the UK. That’s well over 100 pups a year and, records show, more than 10 percent of all vizsla puppies registered.

Yogi, you dog you.

The impressive/shameful statistics were gathered by Jemima Harrison, who prepared the BBC documentary Pedigree Dogs Exposed, and who says — though we joke somewhat about Yogi”s rampant sex life  – they should raise serious concerns about his growing gene pool dominance.

“Yogi is an absolutely beautiful dog who deserved to win,”  Harrison said. “However, the concern is that this dog has been massively overused as a stud dog already … As far as the breed is concerned it’s a genetic time bomb.”

Even England’s Hungarian Vizsla Club is worried about Yogi, who is already grandfather to 340 pups and great grandfather to 10 pups, according to a report carried in The Herald Sun in Australia.

“When you lessen the gene pool you open the breed up to the possibility of auto-immune-related diseases,” said a club spokeswoman.

Yogi earns up to $1,230 per litter, and has fathered 79 registered litters in the UK up to December last year. With his Crufts victory, his stud fee and demand for his studly services can only be expected to increase.

With so many of his pups out there, it’s no surprise there is a Facebook page, called “I have a Yogi vizsla,” dedicated to his offspring.

How the sharpei got its wrinkles

sharpei2

 
How did the sharpei get its wrinkles?

Scientists who have analyzed the genetics of 10 dog breeds say they’ve found the answer — and a path to many more.

While five genes have already been pinpointed as being responsible for dogs’ coats, leg size and more, the new research identifies 155 distinct locations in the animals’ genetic code that could play a role in giving breeds their distinctive appearances.

In the sharpei, the team found differences in a gene known as HAS2 which makes an enzyme known to be important in the production of skin.

“There was probably a mutation that arose in that gene that led to a really wrinkly puppy and a breeder said, ‘hey, that looks interesting, I’m going to try to selectively breed this trait and make more of these dogs’,” explained Joshua Akey from the Department of Genome Sciences at the University of Washington, told the BBC.

Akey and colleagues studied 32 wrinkled and 18 smooth-coated sharpeis and compared a specific stretch of their DNA with that of other breeds.

The team found four small, but significant, differences in the genetics of the two skin types of the sharpei versus the other breeds. These single nucleotide polymorphisms (SNPs), as they are called, were located in the HAS2 gene.

The research has also identified other locations in the dog genome that can now be investigated further to understand better why pedigree animals look the way they do.

Akey and his colleagues reported their findings in the Proceedings of the National Academy of Sciences.

Doggie OCD may provide clues for humans

Scientists studying compulsive behaviors in Doberman pinschers have located a gene they believe is associated with OCD — a finding that could lead to pinpointing a genetic source of obsessive-compulsive disorder in humans.

In dogs, compulsive behavior includes tail chasing, licking their legs until they develop infections, and pacing and circling — canine versions, perhaps, of repeated hand washing and other behaviors displayed by the 2.2 million Americans estimated to be affected by the disorder.

The Doberman study was done by researchers at the Cummings School of Veterinary Medicine at Tufts University, the University of Massachusetts Medical School in Worcester, and the Broad Institute, according to the Boston Globe.

Scientists took samples from 92 Doberman pinschers that displayed compulsive behavior. Dogs with the disorder compulsively suck their flanks or blankets. Researchers also used samples from 68 normal dogs, and did a genome-wide scan, searching for spots that varied between the two samples.

They found a genetic hot spot in dogs with the compulsive behavior — within in a gene called Cadherin 2, known to be active in the brain and in a family of genes recently implicated in autism.

Dr. Dennis Murphy, a laboratory chief in the National Institute of Mental Health, said he is working to follow the research by studying the same gene in more than 300 human patients with OCD, 400 of their relatives, and about 600 people without OCD.

“Identifying a specific gene that could be a candidate gene for a complex disorder like OCD is a gift to have,’’ Murphy said. “This might be a quick route in to a meaningful gene that just could be involved in the human disorder, as well.’’

DNA testing saves dog from execution

petdnaIt took a DNA test to prove it, but Angie Cartwright — who lives in a town that bans pit bulls — has certified that her dog Lucey is only 12 percent bully breeds, and now she has her back.

Lucey had never bitten anyone; nor had she ever acted aggressively, according to the Salina Journal in Kansas. But she was scooped up by animal control officers.

The officers explained that they were taking Lucey to a veterinarian for a breed check — a professional opinion (meaning veterinarian’s guess) to determine Lucey’s breed.

Since 2005, Salina has had a ban on owning unregistered pit bulls and mixed breeds that are predominantly pit bull.

Cartwright got approval to have her vet conduct DNA breed analysis test, ther results of which led to the return of her dog.

The blood test found that a minor amount of Lucey’s DNA came from Staffordshire bull terrier genes — just over 12 percent.

“Maybe this can save someone’s animal, hopefully,” Cartwright said. Read more »

Three genes account for variation in dog coats

dogcoat

 
Short, shaggy, smooth or wiry, nearly all the differences in dogs’ coat types result from variations in just three genes, according to newly published research.

Variations in the DNA  in more than 1,000 dogs from 80 breeds were studied by the researchers, and compared to descriptions of various coat types, according to an Associated Press report.

The study, published Thursday in the online edition of the journal Science, found that nearly all of the varieties of dog coats can be accounted for by combinations of genes called RSPO2, FGF5 and KRT71.

“What’s important for human health is the way we found the genes involved in dog coats and figured out how they work together, rather than the genes themselves,” said Dr. Elaine A. Ostrander of the National Human Genome Research Institute in Bethesda.

“We think this approach will help pinpoint multiple genes involved in complex human conditions, such as cancer, heart disease, diabetes and obesity,” Ostrander, chief of the cancer genetics branch, said in a statement.

The findings apply to purebred dogs: “We don’t know enough about the genetics of mutts,” commented co-author K. Gordon Lark, a biology professor at the University of Utah.

Dogs are descended from wolves and, like wolves, short-haired dogs such as beagles had only the ancestral forms of the three genes, none with variations.

Dogs like President Obama’s Portuguese Water Dog have variations in all three genes, producing animals with curly hair plus a “mustache” and large eyebrows.

Dog genes responsible for dark-coated wolves

North American wolves that are darker in color apparently inherited the trait from dogs.

Although it’s well known that dogs descended from wolves, National Geographic reports, a new study implies that some genetic material moved backward in the evolutionary chain.

Thousands of years ago, the researchers suggest, a few wolves mated with dogs — possibly pets kept by Native Americans — creating hybrid animals that passed on their genes. The study appears in this week’s issue of the journal Science.

Outside North America, where dark wolves can make up 10 to 70 percent of a given population, only Italy is known to have wolves with darker coats.

Scientists know there are particular gene receptors that cause dark colors in animals. But when Barsh and colleagues looked at variations of those genes in wolves and coyotes, they learned that those variations didn’t affect the color of the canines’ fur. Instead, a more unique gene that darkens fur in dogs was found in dark wolves and coyotes from Wyoming’s Yellowstone National Park and the Canadian Arctic.

“It’s quite clear that black wolves are just as much wolf as a non-black wolf,” said study co-author Greg Barsh, a geneticist at Stanford University in California. But this small amount of dog genes may have given black-coated wolves a selective advantage.

“It does seem natural to say, Oh, well there’s more black wolves in the forest because that helps them blend into their environment,” Barsh said.

But wolves don’t depend on camouflage to hunt, biologists have found, suggesting that the benefit of being genetically coded for dark fur might not be related to color. It turns out the same gene is involved in humans in helping bolster the immune system to fight off infection, Barsh said.

The new study may also help conservation biologists think beyond traditional views on genetic diversity, Barsh added.

“There is sometimes one school of thought that to preserve species diversity is to keep the natural population pure,” he said. “This is an example where preserving genetic diversity has in fact been facilitated by a hybridization event with a domesticated animal.”

Collapsing Labradors: mutant gene blamed

Genetic scientists said Sunday they think they have figured out why some Labrador retrievers – the most popular dog breed in the world — are prone to collapsing after exercise.

The tendency among some Labradors, after as little as five minutes of strenuous exercise, to develop a wobbly gate, run a fever and lose control over their rear legs, was first spotted by vets in the 1990s.

Now, scientists say the syndrome, called exercise-induced collapse, is likely caused by mutation of a gene called dynamin 1, or DNM1, on the dog’s ninth chromosome that controls a key chemical in the nervous system.

In an experiment reported Sunday, University of Minnesota researchers carried out a gene scan of 96 dogs, 60 of which had the syndrome. Up to 30 per cent of Labrador retrievers carry the mutation, though only three to five per cent of them suffer from exercise-induced collapse, the scientists said.

The study appears in Nature Genetics, a journal of the British-based Nature Publishing Group.

The University of Minnesota team developed a gene test to see whether dogs have the normal or mutated form of DNM1, which could help dog breeders.

“This is very exciting because it is the first naturally occurring mutation of this gene identified in any mammal,” said James Mickelson, a professor of veterinary sciences at the university. “Its discovery could offer insight into normal as well as abnormal neurobiology in both animals and humans.”