Biologists reconstruct genome of 11,000-year-old “almost immortal” sexually-transmitted dog cancer

Canine transmissible venereal tumours (CTVT) is one of only two natural transmissible cancers, and could hold the key to better organ transplants in humans.

Veterinary biologists have discovered that a sexually-transmitted cancer found in dogs around the world first originated 11,000 years ago, making it potentially the oldest living mammalian creature.

The study from the Wellcome Trust’s Sanger Institute, published in Science, analysed the genome of canine transmissable venereal tumours (CTVT), a disease that is one of only two known cancers of its type to have been observed in the natural world (the other, transferred via bites, affecting Tasmanian devils). It’s not a cancer caused by the transfer of a virus, like with cervical cancer and the HPV virus in humans - it’s the transfer of actual cancerous dog cells from dog to dog.

“They are actually a parasite, they need to have their host in order to survive, but they’re actually derived from the same species as their host,” Dr Elizabeth Murchison, the study’s lead author, explained to me. “They’re quite a strange disease. They are an infectious disease, but they’re originally from the same species as their host, which makes them a kind of very tricky to combat.”

“It’s the oldest continually surviving mammalian lifeform that we know of,” she said. “It is almost immortal.”

Genome analysis of samples from a dog in Brazil and another Australia found that the cancer had undergone a huge number of mutations, in the order of two million, since it first began metastasising within the first dog to contract it.

Murchison said: “Between humans we each have about three million mutations, the natural variance that makes us different to other people. Similarly dogs have about three million natural variants that make one dog different to another dog. But cancers themselves, in humans, don’t tend to differ from their host very much. They usually have between 1,000 and 5,000 mutations in the genome that makes the cancer different to the host. Whereas this dog cancer has acquired about two million, which is almost making it like a different individual to the original host that gave rise to it.”

Relying on recent research which found that, within cancer patients, the number of mutations within a cancer correlates both to the type of cancer and the age of the patient, the study team were able to trace back in time to the point at which mutations must have started - giving the age of CTVT at 11,000 years.

Yet CTVT stayed within the small population where it first emerged for roughly 10,500 years, until suddenly spreading elsewhere around the globe - a time that coincides with the beginnings of the European age of exploration. While there’s no way to know where in the world the cancer first appear (yet), the earliest known historical mention of it is by a London doctor in 1810.

With the information from the origin dog’s genome, the team was able to create an image of what it probably looked like. Here's a video from the team further explaining their work:

What’s more, the cancer appears to have been caused by in-breeding.

“It was a relatively inbred individual,” explains Murchison. “Similarly, the Tasmanian devils are relatively inbred population - they live on an island, and they have a small population. The cancer might have originated in a dog that lived in an in-bred population, but from there it managed to adapt into all sorts of out-bred dogs. It can even survive in other species of canids, including jackals and coyotes and foxes. It’s pretty remarkable.”

Theoretically, this type of cancer could emerge at any time in any species, Murchison pointed out, but the experience of the dog and Tasmanian devil transmissible cancers - and from a third variant, which emerged briefly in a population of laboratory hamsters in the 1960s - seems to indicate that in-bred populations are more at risk. There are human populations which suffer from low genetic diversity around the world, and this research could be important in understanding transmissible cancers in the case of a variant appearing.

“These cancers have to overcome one of the most fundamental immunological barriers, and how they do it is still a mystery,” Murchison said. “It’s incredibly important to understand how they do it, as it has implications for how cancers evade the immune system, but also potentially how other infectious diseases might work, and have implications for how to design better methods for helping transplant recipient patients not to reject their graft transplant organs.”

Murchison is also keen to see if further research could help the endangered Tasmanian devil, whose variant is much more aggressive than CTVT and which can kill its host in a matter of months.

What the first dog to get CTVT may have looked like. (Image: Sanger Institute)

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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7 problems with the Snooper’s Charter, according to the experts

In short: it was written by people who "do not know how the internet works".

A group of representatives from the UK Internet Service Provider’s Association (ISPA) headed to the Home Office on Tuesday to point out a long list of problems they had with the proposed Investigatory Powers Bill (that’s Snooper’s Charter to you and me). Below are simplified summaries of their main points, taken from the written evidence submitted by Adrian Kennard, of Andrews and Arnold, a small ISP, to the department after the meeting. 

The crucial thing to note is that these people know what they're talking about - the run the providers which would need to completely change their practices to comply with the bill if it passed into law. And their objections aren't based on cost or fiddliness - they're about how unworkable many of the bill's stipulations actually are. 

1. The types of records the government wants collected aren’t that useful

The IP Bill places a lot of emphasis on “Internet Connection Records”; i.e. a list of domains you’ve visited, but not the specific pages visited or messages sent.

But in an age of apps and social media, where we view vast amounts of information through single domains like Twitter or Facebook, this information might not even help investigators much, as connections can last for days, or even months. Kennard gives the example of a missing girl, used as a hypothetical case by the security services to argue for greater powers:

 "If the mobile provider was even able to tell that she had used twitter at all (which is not as easy as it sounds), it would show that the phone had been connected to twitter 24 hours a day, and probably Facebook as well… this emotive example is seriously flawed”

And these connection records are only going to get less relevant over time - an increasing number of websites including Facebook and Google encrypt their website under "https", which would make finding the name of the website visited far more difficult.

2. …but they’re still a massive invasion of privacy

Even though these records may be useless when someone needs to be found or monitored, the retention of Internet Connection Records (IRCs) is still very invasive – and can actually yield more information than call records, which Theresa May has repeatedly claimed are the non-digital equivalent of ICRs. 

Kennard notes: “[These records] can be used to profile them and identify preferences, political views, sexual orientation, spending habits and much more. It is useful to criminals as it would easily confirm the bank used, and the time people leave the house, and so on”. 

This information might not help find a missing girl, but could build a profile of her which could be used by criminals, or for over-invasive state surveillance. 

3. "Internet Connection Records" aren’t actually a thing

The concept of a list of domain names visited by a user referred to in the bill is actually a new term, derived from “Call Data Record”. Compiling them is possible, but won't be an easy or automatic process.

Again, this strongly implies that those writing the bill are using their knowledge of telecommunications surveillance, not internet era-appropriate information. Kennard calls for the term to be removed, or at least its “vague and nondescript nature” made clear in the bill.

4. The surveillance won’t be consistent and could be easy to dodge

In its meeting with the ISPA, the Home Office implied that smaller Internet service providers won't be forced to collect these ICR records, as it would use up a lot of their resources. But this means those seeking to avoid surveillance could simply move over to a smaller provider.

5. Conservative spin is dictating the way we view the bill 

May and the Home Office are keen for us to see the surveillance in the bill as passive: internet service providers must simply log the domains we visit, which will be looked at in the event that we are the subject of an investigation. But as Kennard notes, “I am quite sure the same argument would not work if, for example, the law required a camera in every room in your house”. This is a vast new power the government is asking for – we shouldn’t allow it to play it down.

6. The bill would allow our devices to be bugged

Or, in the jargon, used in the draft bill, subjected to “equipment interference”. This could include surveillance of everything on a phone or laptop, or even turning on its camera or webcam to watch someone. The bill actually calls for “bulk equipment interference” – when surely, as Kennard notes, “this power…should only be targeted at the most serious of criminal suspects" at most.

7. The ability to bug devices would make them less secure

Devices can only be subject to “equipment interference” if they have existing vulnerabilities, which could also be exploited by criminals and hackers. If security services know about these vulnerabilities, they should tell the manufacturer about them. As Kennard writes, allowing equipment interference "encourages the intelligence services to keep vulnerabilities secret” so they don't lose surveillance methods. Meanwhile, though, they're laying the population open to hacks from cyber criminals. 


So there you have it  – a compelling soup of misused and made up terms, and ethically concerning new powers. Great stuff. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.