Category Archives: DNA

Will the Woolly Mammoth Be the First Animal to Become De-Extinct?

Over the last decade, there’s been quite a debate about whether or not, and perhaps more importantly whether or not we should, clone the woolly mammoth back to life. So far, researchers have made some progress on the first question at least. Back in 2005, the Mammoth Creation Project suggested that a creature with 88 percent resemblance to extinct species of mammoth could be cloned successfully within the next 50 years. Already, they may have their first major breakthrough in the processes of cloning.

One of the most prominent geneticists in the United States has successfully managed to extract DNA out of the frozen remains of a frozen mammoth discovered at Wrangel Island in the Arctic Ocean. Although the original strands of DNA are long dead, there was enough genetic information on the animal, which was well preserved with skin and hair, to build a synthetic replica which they then implanted inside the cells of an Indian Elephant – the mammoth’s closest living relatives, which are also about the same size. The elephant cells were kept isolated inside a petri dish. With the aid of a revolutionary (and somewhat controversial) DNA splicing technique known as CRISPR that allows for unprecedented accuracy, which allows for editing genes and even spreading them to the next generation. Lead researcher George Church, of Harvard University, has proudly reported that so far the cells are doing quite well.

The woolly mammoth died out some 10,000 years ago on the mainland in North America, roughly two millennia after mammoth species died out in Europe. The smaller ones indigenous to Wrangel Island, however, lived on peacefully without our intervention until about 1650 BC, overlapping with the rise of civilization in ancient Egypt and the construction of the oldest pyramids at Giza. Before then, they had dominated the Earth for 250,000 years during the Pleistocene Age, thriving during the last of Earth’s five major ice ages, when the planet was between nine and eighteen degrees Fahrenheit colder than it is today. This climate is the primary reason that mammoths, mummified under layers of snow and ice are so easy to find in prime condition, particularly as the Siberian permafrost thaws. Some have even revealed what their fur looked like. So plentiful were the carcasses at one point, that the 1951 Explorers’ Club’s annual dinner in Manhattan actually offered small morsels of mammoth meat for appetizers.

As temperatures became warmer and sea levels began to rise once again, life became a bit harder for the woolly mammoth, particularly around 18,000 years ago, when tribes of hunter-gatherers grew bigger and more organized, successfully hunting them down in large numbers. While Church and his team of researchers were not yet able to fully replicate a complete woolly mammoth genome so what they did was make copies of the genes responsible for the ‘mammoth-like’ attributes that we know – like heavy layers of fat to protect against the cold climate, the ears, which are actually shorter than the ones on modern elephants, tusks, and heavy coats of fur.

“We prioritised genes associated with cold resistance including hairiness, ear size, subcutaneous fat and, especially haemoglobin,” Church revealed to Ben Webster of The Sunday Times. Hemoglobin may have been the key genetic ingredient in helping mammoths tolerate extreme winters. Regardless of the temperature, this protein managed to keep oxygen traveling to the muscles at a constant speed, and may have allowed the mammoths to develop cooling systems for their limbs. By comparison, the hemoglobin in modern elephants, like humans, functions better in warm weather.

While there are samples of flesh and hair that would seem like natural reservoirs for DNA, the trouble is that the meat that has been found is thoroughly rotten, and while the fur shows an orange color, paleontologists have had to adjust the colors they’ve found for what may have been damage to the pigments from being trapped for so long under the ice. Another problem is that many of the mammoths born later clearly suffered birth defects. Cervical ribs that appear in some of the later females may have led to reproductive stress, joining overhunting and climate change as a possibility for their gradual decline.

While people have certainly played at least a partial role in the animal’s disappearance, our technology may eventually bring them back. According to Church: “We now have functioning elephant cells with mammoth DNA in them. We have not published it in a scientific journal because there is more work to do, but we plan to do so.” If successful, we may soon see the first mammoth in nearly 3,300 years.

The technique that combines elephant DNA with the extinct mammoth genome is CRISPR/Cas9, which has lately been used to develop transgenic organisms with an impressive track record. This marks the first time, however, that the technology has taken on the DNA of an extinct organism.

The researchers will next work to determine the best way to reproduce their work with elephant cells outside of the petri dish. It’s actually quite a tall order, but if they are somehow able to this with the use of elephant eggs, then they just might be able to program an elephant that will grow up to be just like a woolly mammoth. The question, however, is whether doing so would be a good idea. De-extinction is a point of contention among many researchers. Not all of them are quite enthusiastic about the idea. According to biologist Alex Greenwood from the Leibniz Institute for Zoo and Wildlife Research, in an interview with The Telegraph:

“We face the potential extinction of African and Asian elephants. Why bring back another elephantid from extinction when we cannot even keep the ones that are not extinct around? What is the message? We can be as irresponsible with the environment as we want. Then we’ll just clone things back?

Money would be better spent focusing on conserving what we do have than spending it on an animal that has been extinct for thousands of years.”

He certainly raises some good points. There are only a few rhinoceroses and a continuously declining population of iconic wildlife throughout Africa, elephants and even the predators like lions suffering from disease. The woolly mammoth would be returning to the world, entering an ecosystem that has adapted to thousands of years of life without them, and require a specialized diet. If we’re already having problems with spreading populations of invasive species, then bringing back extinct species might create an entirely new headache.

On the other hand, many grasslands in North America are showing the impact of having lost their larger grazers such as the megatherium (a bear-sized sloth), 18,000 years after the fact. Perhaps there is the promise of some ecological stability taking place, or perhaps further cultivating the mammoth genome may lead to further improvements in the technology of gene editing. If not an extinct species, perhaps this experiment might also lead to focusing on the preservation of species that only recently died out or those currently extinct in the wild, such as the black rhinoceros. We might be too late in having a thorough debate on the matter anyway, as Church’s team is only one of three research teams in the world actively at work on bringing back the woolly mammoth, but the fact that the issue has been raised alone is important, if only for bringing to the table new ways to preserve already endangered species.

James Sullivan
James Sullivan is the assistant editor of Brain World Magazine and a contributor to Truth Is Cool and OMNI Reboot. He can usually be found on TVTropes or RationalWiki when not exploiting life and science stories for another blog article.

Ancient Celts Were Not Genetically Unique from the Rest of Europe

The Celts, in addition to being a basketball team from Boston, were at one time a distinct cultural presence throughout much of Western Europe during the age of Antiquity, and dominant well into the early Middle Ages, even long after they converted to Christianity. While they have prominent burials and monuments that can be found throughout Europe – they have typically been associated with the culture of Ireland and Scotland, despite having encampments as far as Slavic countries such as Poland.

These people, who created Europe’s first intricate road system in what is now modern France, never actually referred to themselves as Celtic. Rather, the name “Keltoi” meaning “mysterious” was first applied to them by the ancient Greeks, who looked down on them as barbarians of the north – due to such factors as their unusual language (the third oldest in Europe, after Greek) and their pagan religion that recognized nearly 400 different gods and was rumored to involve human sacrifice.

So what set these tribes apart from the many nomadic tribes of ancient Europe? A bit less than was once imagined, as a recent DNA analysis of modern day Britons suggests that the Celts cannot be defined genetically in the United Kingdom.

The data, published in Nature this week, suggests that people of so-called “Celtic ancestry” from Scotland and Cornwall are more closely linked to English ancestry than they are to any other Celtic groups.

The study also described a few genetic differences throughout Great Britain, which indicate various regional identities.

One of the most crucial events in ancient English history is the invasion of the Anglo Saxons some 1,500 years ago, who rather than eradicate the Britons living on the island, ended up assimilating with them.

For their study, the researchers surveyed 2,000 individuals, largely middle-aged and Caucasian, who lived throughout the United Kingdom. Each participant was also required to include data of all four grandparents in the study, many who came from rural areas.

The selection method separated the population from those with long lines of British ancestry from those that immigrated to the U.K. in the early to mid-20th century.

Professor Peter Donnelly who led the study, said that the results show that while the results do not single out the existence of one genetic Celtic group, regional identities in Great Britain do have a genetic basis.

“Many of the genetic clusters we see in the west and north are similar to the tribal groupings and kingdoms around, and just after, the time of the Saxon invasion, suggesting these kingdoms maintained a regional identity for many years,” he said to BBC News.

Prof Donnelly and his team compared the genetic patterns they found against a map of the British Isles from approximately the year AD 600, shortly after the arrival of Anglo Saxons from the area that is currently southern Denmark and northern Germany in the early Middle Ages. By the seventh century, they managed to occupy most of central and southern England.

“We see striking similarities between the genetic patterns we see now and some of these regional identities and kingdoms we see in AD 600, and we think some of that may well be remnants of the groupings that existed then,” he said.

The study was funded by Wellcome Trust, which is currently involved with the People of the British Isles Research Project. The researchers had also learned that people living in northern England have more genetic similarities to people living in Scotland than to those living in southern England.

People of both North and South Wales also have a greater genetic disparity between each other than English people do from the Scots living north of them; and in Northern Ireland there are in fact two distinct genetic groupings – uncovering considerable patterns of migration throughout Late Antiquity.

Prof Mark Robinson is an archaeologist and colleague of Prof Donnelly at Oxford University, and was “very surprised” that these groups of what were culturally Celtic people living in Cornwall, Wales, Northern Ireland and Scotland had so many diverse genetic patterns.

“I had assumed at the very early stages of the project that there was going to be this uniform Celtic fringe extending from Cornwall through to Wales into Scotland. And this has very definitely not been the case,” said Robinson.

Distinct genetic groups formed in each region – but bore many differences between each other.

“Although people from Cornwall have a Celtic heritage, genetically they are much, much more similar to the people elsewhere in England than they are to the Welsh for example,” said Prof Donnelly.

“People in South Wales are also quite different genetically to people in north Wales, who are both different in turn to the Scots. We did not find a single genetic group corresponding to the Celtic traditions in the western fringes of Britain.”

The finding is the first time DNA evidence has supported an assertion that archaeologists like Robinson have long been making. The Celts were much more of a shared culture than a label that refers to a line of descent.

Robinson was happy with the results for another reason as well. They brought a little more objective evidence on what historians have long labeled as Britain’s Dark Ages, between AD 400 and 600, after which the ancient Roman Empire fell and their soldiers no longer occupied the island.

Entire towns became abandoned in the years that followed. The language spoken throughout much of what is now England changed to Anglo Saxon, which later evolved into Middle and modern English. Even the pottery styles changed, and new grains were grown, introduced to the isle from Denmark.

A long point of contention between both historians and archaeologists alike was whether the cultural changes were the result of the Saxons not only successfully occupying the island, but also fully replacing the population when they moved west. This could have been likely were the Saxons to spread disease, as one possibility.

Other evidence suggests that the Britons remaining just gave up their culture for the newly introduced Saxon ways.

The new analysis revels moderate levels of Saxon DNA, indicating that native Britons and Saxons lived alongside each other, and eventually became English. However, some evidence shows that this may not have happened quickly, but the result of eventual trade between British and Saxon communities over at least a century.

For possibly the first time, genetics has been able to give a clearer picture into a long historic controversy, where written sources are scarce.

As this all happened, the Celts likely retained their identity throughout both the western and northern regions of England when regions became occupied by Anglo Saxon conquest.

So what about all the variation between Anglo Saxons and Celtic populations? It could be as simple as a product of time, according to Donnelly.

“If groups have been separated for a period of time, they will diverge genetically so some of the differences we see genetically are the result of those kinds of effects,” he said.

Of the two genetic groupings isolated in Northern Ireland: one is closely related to their neighbors living across the sea in western Scotland and in the Highlands; while the other has been traced to individuals in both the southern portions of Scotland and England.

The former grouping is similar to patterns seen near what was once the kingdom of Dal Riata 1,500 years ago, a land divided among three brothers according to legend. The other grouping likely represents the descendants of the Ulster Plantations.

The Orkney Islands also finds some traces of Norwegian DNA, reflecting the Islands’ settlement by the Vikings. However, it occurs at levels fairly low, suggesting that a great deal of assimilation took place, casting some doubt that the Vikings were nothing but bloodthirsty warriors – they did in fact have considerable interaction with the people on the Islands. The concentrations are about the same as the traces of Anglo Saxon DNA on the mainland.

When the Vikings invaded England, they did destroy a number of villages that they marauded through, establishing a ruling council known as the Danelaw as they conquered new territory. However, these raids left little genetic evidence, if they left any at all – indicating swift military victories rather than the encroachment of large populations on the area and assimilation of culture.

By comparison, the Norman invasion in 1066, the last time that Great Britain was successfully conquered by a foreign invader, the legendary William the Conqueror, also left little genetic evidence.

James Sullivan
James Sullivan is the assistant editor of Brain World Magazine and a contributor to Truth Is Cool and OMNI Reboot. He can usually be found on TVTropes or RationalWiki when not exploiting life and science stories for another blog article.

Accidental Discovery Could Turn Cancer Cells Into Cancer-Attacking Immune Cells

Unexpected results are sort of the point of lab experiments. Laboratory studies reveal the unforeseen and if they didn’t, there would seldom be a reason to perform lab studies. It can be problematic when scientists don’t get the results they wanted or thought to expect but other times new data can be the result of the unexpected, and lead to discoveries no one thought to check for in the beginning. Some famous discoveries happened on total  accident throughout scientific history. The latest unintentional discovery might make one of the most aggressive types of cancer more treatable than ever before.

Scientists at Stanford recently discovered a way to force leukemia cells to become mature immune cells do something amazing.  The researchers were actually trying to stabilize cancer cells so they could keep them alive longer in order to study them. The method of keeping the cells alive allowed the cells to develop into immune cells that may one day help the immune system attack cancerous tumor cells!

You can read the study in full at Proceedings of the National Academy of Sciences.

Acute lymphocytic leukemia (ALL) is the name for a particularly rapidly-progressing cancer where the immature cells that should differentiate and become white blood cells or lymphocytes instead become cancerous.  ALL has several classifications based on which kind of lymphocyte (B cell or T cell) the mutated cancer cell originated from.

The scientists were simply investigating a common type of lymphoblastic leukemia, an acute cancer called precursor B cell ALL, aka B-ALL. B-ALL starts as a rogue B cell mutating away from usefulness during an early part of its maturation. The immature cells can’t fully differentiate and become the B cells they were otherwise destined to be. The flawed B cells lack the  transcription factors  required for normal development. Transcription factors are basically proteins that attach themselves to sections of DNA and are then supposed to switch designated genes on or off, depending on the type of transcription factor.  Did you follow that? It’s a bit technical for the layman but most of us understand DNA. Transcription factors are basically a DNA reader than helps the cell decide which part of your DNA it should use to become a specific type of cell.

So, when a transcription factor messes up and activates the wrong section of DNA or doesn’t activate the correct section, it can cause mutations where the cell doesn’t develop or develops poorly. B-ALL is one of the most nasty types of cancer and the  prognosis for victims is not good. The Stanford U team wanted to study this villain but had trouble keeping the cancer cells alive outside of the victims body.

Lead researcher Ravi Majeti reported in the lab’s news release: “We were throwing everything at the cells to help them survive.”

One of the techniques they used to attempt to keep the cancer cells from dying involved exposure to a certain transcription factor. The exposed cells began to grow and change shape, and the new morphology was a type of white blood cell called a macrophage, normally responsible for attacking  damaged, mutated cells or foreign material.

The team recognized the cancerous cells behaved the same as macrophages in various ways such as surrounding and engulfing bacteria. Most notably, the pseudomacrophages from the cancer cells of mice added back into the cancerous mouse did not behave as a cancer cell, and the mice who did not have cancer did not develop cancer after being exposed.

The Stanford researchers believe the newly converted cells are no longer cancerous. Furthermore, they might even help the body’s immune system regroup and attack other, still cancerous cells. It could work because macrophages normally collect DNA tags from abnormal cells they encounter and also mark foreign material so that other cells in the immune system know what to attack. Since the false macrophages were originally cancerous cells, they will, in theory,  already possess the correct signals that recognize the same kind of  cancer.

Now that this principle has been identified as a possible method of treating one cancer, it might open the door to helping the immune system combat other cancers.

Related Cosmoso article: Pre-Darwinian Theory of Heredity Wasn’t Too Far Off

Jonathan Howard
Jonathan is a freelance writer living in Brooklyn, NY