Tag: Genetics

The Most Inbred People Of All Time | Random Thursday

From the most powerful royalty in history to an uncontacted village in New York State, we’re talking about some of the most inbred people of all time.

The Blue Fugates of Kentucky were an isolated group of settlers who, through a rare recessive gene, developed blue skin. Due to their blue skin and their isolated location, they began to inbreed, eventually becoming something of a local legend – the blue hillbillies that live in the woods – until they reappeared in the 1960s.

Allentown, New York, is a village in New York State that was cut off from the rest of society after a dam flooded the valley where they lived. They call their community The Hollow, but outsiders call it Allentown because almost everybody there is from the same family.

The Habsburgs of Europe were one of the most powerful families in history, ruling over the Holy Roman Empire in Eastern Europe until the early 20th century. But one segment of the Habsburgs in Spain, known as the Spanish Habsburgs, participated in incest and inbreeding for so long that they developed The Habsburg Jaw – a genetic deformity that got so bad that many could barely speak. It was Charles II of Spain that finally put an end to this practice because he was so inbred that he couldn’t reproduce.

And the Egyptian royal family of ancient Egypt practiced inbreeding for over a thousand years because they believed that the only person who could mate with a pharaoh was someone else from their family – they were living gods after all. By the time King Tutankhamen was born, their lineage was so ruined that he had multiple genetic deformities and died at only 18.

Scientists Produce Healthy Mice Born To Same-Sex Parents Using Stem Cells And Gene Editing

Scientists have been able to breed mice with same-sex parents using a breakthrough technique involving stem cells and gene editing.

Researchers at the Chinese Academy of Sciences have produced healthy mice with two mothers, who were then able to go on to reproduce themselves.

Mice with two fathers were also born during the study, but only survived for a matter of hours.

Using female same-sex parents, the scientists were able to produce a total of 29 live mice from 210 embryos.

All these offspring were normal, lived to adulthood, and were able to give birth to offspring of their own.

The study, published in scientific journal Cell Stem Cell, examined why same-sex mammals are not typically able to reproduce, suggesting stem cells and targeted gene editing can make the process easier.

We were interested in the question of why mammals can only undergo sexual reproduction,” the study’s co-senior author Dr Qi Zhou said.

We have made several findings in the past by combining reproduction and regeneration, so we tried to find out whether more normal mice with two female parents, or even mice with two male parents, could be produced using haploid embryonic stem cells with gene deletions.




While some species of reptiles, amphibians and fish can change gender in order to reproduce or exist as both male and female at the same time, same-sex reproduction for mammals is a more difficult proposition, Dr Zhou said.

He said in mammals, certain maternal or paternal genes are shut off during the development of sperm and egg cells, meaning offspring that do not receive genetic material from both a mother and father might experience developmental abnormalities.

By deleting imprinted genes from immature eggs, researchers have in the past been able to produce mice with two mothers, although most still displayed genetic defects.

To produce healthy bi-maternal mice, Dr Zhou, his co-senior authors Dr Baoyang Hu and Dr Wei Li, and their colleagues used haploid embryonic stem cells (ESCs), containing half the normal number of chromosomes and DNA from each parent.

We found in this study that haploid ESCs were more similar to primordial germ cells, the precursors of eggs and sperm,” Dr Hu said. “The genomic imprinting that’s found in gametes was ‘erased’.

Alongside the 29 healthy mice produced by same-sex female parents, a dozen mice were also born to two male parents during the course of the study.

However, the process of creating mice from same-sex male parents, which involves modifying a larger amounts of genes and inserting fertilised embryos into surrogate mothers, is more complicated.

All offspring from two males born during the study died after less than 48 hours, although scientists believe they can improve the process in future tests.

This research shows us what’s possible,” Dr Li said. “We saw that the defects in bi-maternal mice can be eliminated and that bi-paternal reproduction barriers in mammals can also be crossed through imprinting modification.

We also revealed some of the most important imprinted regions that hinder the development of mice with same-sex parents, which are also interesting for studying genomic imprinting and animal cloning.

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Can People Catch Cancer? Not Likely, But Some Animals Can

These guys are seriously threatened by a contagious cancer, largely because of how much they love to touch each other’s faces.

Recent headlines about contagious cancers found in some animals may make you wonder: Could I catch cancer? In Australia, Tasmanian devils are dying from aggressive facial tumors caused by a contagious virus.

In the Atlantic Ocean, some clams are developing a form of leukemia caused by cancer cells suspended in the water. And scientists have known for years that dogs can spread cancer cells from one to another during intercourse.

Despite recent headlines about cancer being contagious in other species, current data shows it’s virtually impossible in humans,” says Dr. Glen Weiss, Director of Clinical Research and Phase I & II Clinical Trials at our hospital near Phoenix.

“There have been attempts to transfect people without cancer with cancer cells, and it did not work.”

In the 1950s and 1960s, Dr. Chester Southam, a New York immunologist, conducted several controversial experiments by injecting live cancer cells into uninformed cancer patients and healthy prisoners.




While patients in both studies grew tumors, those in the healthy patients were quickly attacked and eliminated by their immune systems.

Foreign cells would more likely be rejected just like an organ donation or bone marrow transplant from a donor,” Dr. Weiss says.

In order to take, a recipient would likely require significant immunosuppression.” Southam was widely criticized for his experiments on humans and his medical license was suspended for one year.

Organ recipients are at a higher risk of developing cancer, but only in rare cases has the cancer been linked to the organ donor having cancer.

Such cases are so rare that some cancer patients are still eligible to donate organs. Some recipients develop cancer because the body’s immune system is suppressed to help prevent organ rejection.

Fortunately, survival of transplanted cancers in healthy humans is exceedingly rare and documented by only a small handful of cases,” Dr. James S. Welsh, a radiation oncologist currently with the Loyola University Health System writes in a 2011 article on contagious cancer.

“Thus, friends and family members of cancer patients and we, as caregivers of cancer patients, need not be unduly concerned with the remote possibility of ‘catching cancer.”

Humans may spread contagious viruses that lead to cancer. For instance, the human papillomavirus (HPV)  is responsible for virtually all cases of cervical cancer.

It is also linked to most cases of vaginal and vulvar cancer and more than half the cases of penile cancer. The virus is also linked to 90 percent of anal cancers and 72 percent of oropharyngeal cancer.

The hepatitis B and C viruses may lead to hepatocellular carcinoma, the most common type of liver cancer.

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European Colonization Of Americas Wiped Out Native Dogs Alongside Indigenous People

European colonisers arriving in the Americas almost totally wiped out the dogs that had been kept by indigenous people across the region for thousands of years.

The original American dogs were brought across the land bridge that once connected North America and Siberia over 10,000 years ago, by their human owners.

These dogs subsequently spread throughout North and South America, but genetic analysis has revealed they were ultimately replaced by dogs imported from Europe.

This study demonstrates that the history of humans is mirrored in our domestic animals,” said Professor Greger Larson, director of the palaeogenomics and bio-archaeology research network at the University of Oxford and senior author of the research.

People in Europe and the Americas were genetically distinct, and so were their dogs. And just as indigenous people in the Americas were displaced by European colonists, the same is true of their dogs.




In their paper, published in the journal Science, the researchers compared genetic information from dozens of ancient North American and Siberian dogs spanning a period of 9,000 years.

Their analysis showed the dogs persisted for a long time but ultimately vanished, which to Dr Laurent Frantz from Queen Mary University of London said suggests “something catastrophic must have happened”.

It is fascinating that a population of dogs that inhabited many parts of the Americas for thousands of years, and that was an integral part of so many Native American cultures, could have disappeared so rapidly,” said Dr Frantz, who was also a senior author of the study.

Today, few modern dogs possess any genetic traces of the ancient breeds.

The researchers suggested the dogs’ near-total disappearance from the region was likely a result of both disease and cultural changes brought over by Europeans.

It is possible, for example, that European colonists discouraged the sale and breeding of the dogs kept by indigenous Americans.

It is known how indigenous peoples of the Americas suffered from the genocidal practices of European colonists after contact,” said Kelsey Witt, who led part of the genome work as a graduate student at the University of Illinois.

Bizarrely, one of the only traces of genetic information from “pre-contact” dogs can be found in a transmissible tumour that spreads between dogs known as CTVT.

It’s quite incredible to think that possibly the only survivor of a lost dog lineage is a tumour that can spread between dogs as an infection,” added Maire Ní Leathlobhair, co-first author, from the University of Cambridge.

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Here’s What You Need to Know Before You Buy A DNA Testing Kit

It’s amazing how much information there is hiding in one tiny globule of spit.

In 2003, scientists announced that they had, after more than a decade, completed sequencing the human genome.

In 2018, you can spit in a test tube and, for the same price as a pair of Apple Air Pods, find out a host of fascinating information about your ancestry and health.

But there are things you should know before you spit: Namely that you’re you’re handing over access to extremely sensitive information about things including your health, personality, and family history.




It’s all there in the fine print if you bother to read it: Testing companies can claim rights to your genetic information, allow third parties to access it, and simply by virtue of possessing it make your DNA vulnerable to hackers.

This isn’t because DNA testing companies like AncestryDNA or 23andMe are doing anything especially fishy. Sharing sensitive personal information is inherently risky.

And the truth is, we likely don’t even fully understand what some of those risks are. It’s possible you could one day face employment or insurance discrimination, or even social stigma, based on your genes.

We’re guessing you might not have thought about all this before you became one of the millions of people curious to find out what their DNA might say about them.

And, as I explored in a recent feature, the accuracy of the information you get back from these companies is dubious. So we’ll leave you with one important piece of advice: Think before you spit!

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Cosmic Crisp – A New Apple To Get Your Teeth Into

How do you like them apples? Lead scientist Dr Kate Evans at Washington State University’s Tree Fruit Research & Extension Center. Photograph: Ted S. Warren/AP

Nearly 30 years ago, Dr Bruce Barritt was jeered when he branded the apple industry in Washington state a dinosaur for growing obsolete varieties such as red and golden delicious.

Now, farmers in the state, where 70% of US apples are grown, are ripping up millions of trees and replacing them with a new variety, the cosmic crisp, which Barritt, a horticulturalist, has created in the decades since.

With 12m trees to be planted by 2020, and the first harvest of apples due in the shops in 2019, it is the biggest ever launch of a new apple.

Around 10m 40lb boxes are expected to be produced in the next four years, compared with the usual 3-5m for a new variety. It’s a gamble for growers: replanting costs up to $50,000 per acre, so the cosmic crisp needs to fetch top dollar to make their investment worthwhile.

Barritt began his quest for the perfect apple in the 1980s, after being hired by Washington State University (WSU).




I had two projects,” he says. “The orchards being grown were inefficient – big trees that required ladders, poor fruit quality because of shade in the trees… That was a problem I could tackle.

“But I thought the most important problem was that, at the time in Washington, 90% of the crop was red delicious and golden delicious – they’re not crisp, juicy or flavourful.

“I was giving a talk to 2,000 industry people and I told them these were obsolete. It didn’t go down well. If I asked them why they were still growing these varieties, they’d say ‘Because we grow them better than anybody else.’ That wasn’t good enough, because the consumer wasn’t happy.

Barritt was convinced better varieties had to be developed, and made available to every farmer in the state (new varieties such as jazz and ambrosia are often only licensed to small clubs of growers).

He spent six years lobbying the industry in Washington and the university for money to fund a breeding programme, which began in 1994.

Barritt created thousands of seedlings by cross-pollinating the blossoms of parent trees.

‘Sweet but not too sweet’: proof is in the tasting for the cosmic crisp. Photograph: Ted S Warren/AP

When they come into bearing, we walk the long rows and bite, chew and spit, because you can’t eat a lot of apples at once – your taste buds lose their sensitivity.

“The majority you bite into are terrible, but eventually you come up with ones that are good.”

The cosmic crisp, so named because of its yellow star-like flecks on a burgundy skin, is a cross between the honeycrisp and the enterprise.

Honeycrisp’s claim to fame is its crispness; it also has good sugar and acid and texture. Enterprise is large, full-coloured, stores well and is firm. It’s got good acidity and flavour in general.

Enterprise is also known for its resistance to fire blight.

Around this time, Barritt retired. Dr Kate Evans, a British horticulturalist who had been leading breeding programmes for East Malling Research in Kent, took over.

Testing of the apple continued and it was patented in 2014, with Barritt named as the “inventor”. For the next 10 years, it will only be available to US farmers in Washington, because they helped fund the breeding programme.

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Meet The Russian Biologist Who Is Also A Pioneer Of Modern Genetics

Nikolai Konstantinovich Koltsov was a Russian biologist and a pioneer of modern genetics.

Koltsov graduated from Moscow University in 1894 and was a professor there (1895-1911).

He established and directed the Institute of Experimental Biology in the middle of 1917, just before the October revolution and was a member of the Agricultural Academy.

In 1920, Koltsov was arrested as a member of the non-existent “Anti-Soviet Tactical Center” invented by the VCheKa.

Prosecutor Nikolai Krylenko demanded the death sentence for Koltsov (67 of around 1000 arrested people were executed).

However, after a personal appeal to Vladimir Lenin by Maxim Gorky Koltsov was released and was restored to his position as the head of the Koltsov Institute of Experimental Biology.




Nikolai Koltsov worked on cytology and vertebrate anatomy. In 1903 Koltsov proposed that the shape of cells was determined by a network of tubules which he termed the cytoskeleton.

In 1927 Koltsov proposed that inherited traits would be inherited via a “giant hereditary molecule” which would be made up of “two mirror strands that would replicate in a semi-conservative fashion using each strand as a template“.

These ideas were confirmed to have been accurate in 1953 when James D. Watson and Francis Crick described the structure of DNA.

Watson and Crick had apparently not heard of Koltsov. US geneticist Richard Goldschmidt wrote about him: “There was the brilliant Nikolai Koltsov, probably the best Russian zoologist of the last generation, an enviable, unbelievably cultured, clear-thinking scholar, admired by everybody who knew him“.

In 1937 and 1939, the supporters of Trofim Lysenko published a series of propaganda articles against Nikolai Koltsov and Nikolai Vavilov.

They wrote: “The Institute of Genetics of the Academy of Sciences not only did not criticize Professor Koltsov’s fascistic nonsense, but even did not dissociate itself from his “theories” which support the racial theories of fascists“.

His death in 1940 was claimed to have been due to a stroke. However, the biochemist Ilya Zbarsky revealed that the unexpected death of Koltsov was a result of his poisoning by the NKVD, the secret police of the Soviet Union.

The same day his wife, the scientist Maria Sadovnikova Koltsova, committed suicide.

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Ways Being Left-Handed Impacts Your Health

With just 10% of the population being left-handed, it can be easy for everyone else to forget we’re living in a right-handed world.

But aside from making it tough to cut a straight line with a pair of scissors designed for righties, being a southpaw can also have some subtle effects on our physical and mental health.

The brains and bodies of lefties may operate differently than those of right-handed people.

Handedness seems to be determined very early on in fetal development, when a lot of other things about your future are being determined as well,” says Ronald Yeo, PhD, professor of psychology at the University of Texas-Austin.

Here’s a look at some of the most common facts about being left-handed, and what it might really mean for your health.




It’s not just genetics

Scientists aren’t exactly sure why some people are left-handed, but they know that genes are responsible about 25% of the time, says Yeo.

Left-handedness does tend to run in families, he says, “but noticeably less than other inherited traits, like height or intelligence.

In fact, identical twins, who share the same genes, can sometimes have different dominant hands.

There are plenty of theories on what else might determine which hand you write with, but many experts believe that it’s kind of random, says Yeo.

It’s linked to stress in pregnancy

In one British study, the fetuses of super-stressed pregnant women were more likely to touch their faces more with their left hands than their right.

This could be the first signs of a left-handed child, say the researchers. Other evidence supports that theory.

In one 2008 Swedish study of moms and their 5-year-old children, women who were depressed or stressed during their pregnancies were more likely to have mixed- or left-handed kids.

In other studies, babies with low birth weight, or born to older mothers, were more likely to be lefties as well.

It’s more common in twins

Identical twins are sometimes mirror images of each other—one twin has a mole on her right cheek and the other has a mole in the same spot on her left cheek, for instance.

It was once believed that twins’ genetic makeup should be “mirrored” as well—therefore, one twin should be left-handed and the other should be right.

Neither of these is true, but left-handedness is about twice as common in twins than in the general population. A 1996 Belgian study found that about 21% of twins, both fraternal and identical, are left-handed.

It’s linked to a risk of mental health problems

People who are left-handed are at greater risk of psychotic disorders such as schizophrenia, according to a 2013 Yale University study.

When researchers polled patients at a mental-health clinic, 40% of those with schizophrenia or schizoaffective said they wrote with their left hand; that’s considerably higher than the 10% of lefties found in the general population.

Studies have also found links between non-right-handedness and dyslexia, attention deficit hyperactivity disorder, and some mood disorders.

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DNA Of Man Who Died In 1827 Recreated Without His Remains

Recreating a deceased person or animal’s DNA has required that DNA be extracted from the remains of the individual, but a new study has shown that may not be the only way.

The DNA of a man who died nearly 200 years ago has been recreated from his living descendants rather than his physical remains — something that has never been done before.

deCODE Genetics, a biopharmaceutical company in Iceland, achieved this feat by taking DNA samples from 182 Icelandic descendants of Hans Jonatan, a man who is quite an icon in Iceland, most well known for having freed himself from slavery in a heroic series of seemingly impossible events.




It was the unique circumstances of Hans Jonatan’s life that made it possible for his DNA to be recreated after his death. For one, Jonatan was the first Icelandic inhabitant with African heritage.

Iceland also boasts an extensive and highly detailed collection of genealogical records.

The combination of Jonatan’s unique heritage and the country’s record-keeping for inhabitants’ family trees made this remarkable recreation possible.

deCODE used DNA screened from 182 relatives, first reconstructing 38 percent of Jonatan’s mother Emilia’s DNA (which accounted for 19 percent of Jonatan’s).

Published in Nature Genetics, this elaborate study began with a whopping 788 of Jonatan’s known descendants, but was able to be narrowed down to 182 through DNA screening against known markers.

While this is truly an amazing feat, according to Robin Allaby of the University of Warwick in the United Kingdom,  it “seems to be the sort of analysis you could only do under particular circumstances when an immigrant genome is of a very rare type.

Despite these limitations, deCODE believes the technique could have extensive applications.

Kári Stefánsson of deCODE said that “It’s all a question of the amount of data you have. In principle, it could be done anywhere with any ancestors, but what made it easy in Iceland was that there were no other Africans.”

Allaby does believe the results of this study could give us additional avenues to explore the DNA of those who have long since passed.

“It’s the sort of study that could, for instance, be used to recover genomes of explorers who had interbred with isolated native communities.”

Theoretically, a technique like this could help researchers create “virtual ancient DNA,” which would allow scientists to recreate the DNA of historical figures.

Agnar Helgason of deCODE stated that “Any historic figure born after 1500 who has known descendants could be reconstructed.”

While it’s exciting, there are still major hurdles to overcome in terms of the potential future applications.

The quantity, scale, and detail of the DNA from living ancestors required to recreate a person’s DNA make it impractical for use within most families.

Additionally, with each new generation identifiable DNA fragments get smaller and more difficult to work with.

To that end, more immediate applications might involve repairing and filling in spaces within family trees.

But if it’s honed, it could become a valuable historical tool, giving us an in-depth look at what life was like for historical figures like Jonatan.

Scientists could genetically resurrect anyone, providing us with a more thorough understanding of our species both from our own personal familial perspectives and through the more macrocosmic lens of human history.

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Researchers Get Better At Tweaking The Genomes Of Human Embryos

It is risky to predict who and what will win a Nobel prize. But some discoveries are so big that their receipt of science’s glitziest gong seems only a matter of time.

One such is CRISPR-Cas9, a powerful gene-editing technique that is making the fraught and fiddly business of altering the genetic material of living organisms much easier.

Biologists have taken to CRISPR-Cas9 with gusto, first with animal experiments and now with tests on humans.

In March researchers in China made history when they reported its first successful application to a disease-causing genetic mutation in human embryos.

But their results were mixed. Although they achieved 100% success in correcting the faulty gene behind a type of anaemia called favism, they tested the technique in only two affected embryos.

Of four others, carrying a mutation that causes thalassaemia, another anaemia, only one was successfully edited.




Now, in a study just published in Nature, a group of researchers from America, China and South Korea have pulled off a similar trick, with striking consistency, among many more embryos, while avoiding or minimising several of the pitfalls of previous experiments.

Their work suggests that, with a bit of tweaking and plenty of elbow grease, CRISPR-Cas9 stands a good chance of graduating, sooner or later, from the laboratory to the clinic.

The researchers involved, Hong Ma of Oregon Health & Science University and her colleagues, obtained sperm donated by a man who carries a mutated version of a gene called MYBPC3 that causes hypertrophic cardiomyopathy (HCM), a condition in which the walls of the heart grow too thick.

As with the genes that cause thalassaemia and favism, inheriting even a single copy of the malformed version of this gene is enough to cause HCM.

These sperm, half of which would have been carrying the mutated version of MYBPC3, were then used to fertilise eggs containing a normal copy of the gene.

The resulting embryos thus had a 50:50 chance of containing a defective copy. In the absence of editing, and had they been allowed to develop, those with a faulty version would have grown into adults likely to suffer from the disease.

CRISPR-Cas9 editing has been developed from a bacterial defence system that shreds the DNA of invading viruses. CRISPR stands for “clustered regularly interspaced short palindromic repeats”.

These are short strings of RNA, a molecule similar to DNA, each designed to fix onto a particular segment of a virus’s DNA. Cas9 is an enzyme which, guided by CRISPRs, cuts the DNA at the specified point.

The hope was that, by being given such templates, embryos could be purged of nascent genetic disease.

That hope appeared fulfilled, at least in part. By the end of the experiment, 72% of the embryos were free of mutant versions of MYBPC3, an improvement on the 50% that would have escaped HCM had no editing taken place.

In achieving this, Dr Ma and her colleagues overcame two problems often encountered by practitioners of CRISPR-Cas9 editing.

One is that the guidance system may go awry, with the CRISPR molecules leading the enzyme to parts of the genome that are similar, but not quite identical, to the intended target.

Happily, they found no evidence of such off-target editing. A second problem is that, even if the edits happen in the right places, they might not reach every cell.

Many previous experiments, including some on embryos, have led to mosaicism, a condition in which the result of the editing process is an individual composed of a mixture of modified and unmodified cells.

If the aim of an edit is to fix a genetic disease, such mosaicism risks nullifying the effect.

Dr Ma and her colleagues conjectured that inserting the CRISPR-Cas9 molecules into the egg simultaneously with the sperm might help.

That way the process is given as much time as possible to complete its work before the fertilised egg undergoes its first round of cell division.

Sure enough, after three days, all but one of the 42 embryos in which the technique had worked showed the same modifications in every one of its cells.

So far, so good. But a third problem that has bedevilled experiments with CRISPR-Cas9 concerns the quality of the repair. There are at least two ways for cells to repair DNA damage.

One of them simply stitches the severed strands of DNA back together, deleting or adding genetic letters at random as it does so. Because it introduces mutations of its own, this process is not suitable for correcting DNA defects for medical purposes.

Fortunately, the other mechanism patches the break with guidance from a template, and thus without introducing any additional mistakes.

But cells seem to prefer the slapdash approach. In previous CRISPR-Cas9 research, the more precise method was involved only 2% to 25% of the time.

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