Scientists Were Wrong About DNA

(THIS ARTICLE IS COURTESY OF SCITECHDAILY)

 

Scientists Were Wrong About DNA – It Is Actually Held Together by Hydrophobic Forces

DNA Molecule Opening up in a Hydrophobic Environment

For DNA to be read, replicated or repaired, DNA molecules must open themselves. This happens when the cells use a catalytic protein to create a hydrophobic environment around the molecule. Illustration Credit: Yen Strandqvist/Chalmers University of Technology

Researchers at Chalmers University of Technology, Sweden, disprove the prevailing theory of how DNA binds itself. It is not, as is generally believed, hydrogen bonds which bind together the two sides of the DNA structure. Instead, water is the key. The discovery opens doors for new understanding in research in medicine and life sciences. The researchers’ findings are presented in the journal PNAS.

DNA is constructed of two strands, consisting of sugar molecules and phosphate groups. Between these two strands are nitrogen bases, the compounds which make up organisms’ genes, with hydrogen bonds between them. Until now, it was commonly thought that those hydrogen bonds were what held the two strands together.

But now, researchers from Chalmers University of Technology show that the secret to DNA’s helical structure may be that the molecules have a hydrophobic interior, in an environment consisting mainly of water. The environment is therefore hydrophilic, while the DNA molecules’ nitrogen bases are hydrophobic, pushing away the surrounding water. When hydrophobic units are in a hydrophilic environment, they group together, to minimize their exposure to the water.

The role of the hydrogen bonds, which were previously seen as crucial to holding DNA helixes together, appear to be more to do with sorting the base pairs, so that they link together in the correct sequence.

The discovery is crucial for understanding DNA’s relationship with its environment.

Bobo Feng, Chalmers University of Technology

Bobo Feng, Postdoc, Chemistry and Chemical Engineering, Chalmers University of Technology. Credit: Johan Bodell/Chalmers University of Technology

“Cells want to protect their DNA, and not expose it to hydrophobic environments, which can sometimes contain harmful molecules,” says Bobo Feng, one of the researchers behind the study. “But at the same time, the cells’ DNA needs to open up in order to be used.”

“We believe that the cell keeps its DNA in a water solution most of the time, but as soon as a cell wants to do something with its DNA, like read, copy or repair it, it exposes the DNA to a hydrophobic environment.”

Reproduction, for example, involves the base pairs dissolving from one another and opening up. Enzymes then copy both sides of the helix to create new DNA. When it comes to repairing damaged DNA, the damaged areas are subjected to a hydrophobic environment, to be replaced. A catalytic protein creates the hydrophobic environment. This type of protein is central to all DNA repairs, meaning it could be the key to fighting many serious sicknesses.

Understanding these proteins could yield many new insights into how we could, for example, fight resistant bacteria, or potentially even cure cancer. Bacteria use a protein called RecA to repair their DNA, and the researchers believe their results could provide new insight into how this process works – potentially offering methods for stopping it and thereby killing the bacteria.Rad51

 

In human cells, the protein Rad51 repairs DNA and fixes mutated DNA sequences, which otherwise could lead to cancer.

“To understand cancer, we need to understand how DNA repairs. To understand that, we first need to understand DNA itself,” says Bobo Feng. “So far, we have not, because we believed that hydrogen bonds were what held it together. Now, we have shown that instead it is the hydrophobic forces which lie behind it. We have also shown that DNA behaves totally differently in a hydrophobic environment. This could help us to understand DNA, and how it repairs. Nobody has previously placed DNA in a hydrophobic environment like this and studied how it behaves, so it’s not surprising that nobody has discovered this until now.”

More information on the methods the researchers used to show how DNA binds together:

The researchers studied how DNA behaves in an environment which is more hydrophobic than normal, a method they were the first to experiment with.

They used the hydrophobic solution polyethylene glycol, and step-by-step changed the DNA’s surroundings from the naturally hydrophilic environment to a hydrophobic one. They aimed to discover if there is a limit where DNA starts to lose its structure, when the DNA does not have a reason to bind, because the environment is no longer hydrophilic. The researchers observed that when the solution reached the borderline between hydrophilic and hydrophobic, the DNA molecules’ characteristic spiral form started to unravel.

Upon closer inspection, they observed that when the base pairs split from one another (due to external influence, or simply from random movements), holes are formed in the structure, allowing water to leak in. Because DNA wants to keep its interior dry, it presses together, with the base pairs coming together again to squeeze out the water. In a hydrophobic environment, this water is missing, so the holes stay in place.

Reference: “Hydrophobic catalysis and a potential biological role of DNA unstacking induced by environment effects” by Bobo FengRobert P. SosaAnna K. F. MårtenssonKai JiangAlex TongKevin D. DorfmanMasayuki TakahashiPer LincolnCarlos J. BustamanteFredrik Westerlund and Bengt Nordén, 27 August 2019, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.1909122116

Mysterious Indus Valley People Gave Rise to Modern-Day South Asians

(THIS ARTICLE IS COURTESY OF LIVE SCIENCE)

 

Mysterious Indus Valley People Gave Rise to Modern-Day South Asians

a photograph of an ancient skeleton buried in Rakigarhi in India

The skeleton of an individual from the Indus Valley Civilization whose fragile, ancient DNA revealed links to modern-day South Asian populations.
(Image: © Vasant Shinde)

Ancient DNA evidence reveals that the people of the mysterious and complex Indus Valley Civilization are genetically linked to modern South Asians today.

The same gene sequences, drawn from a single individual who died nearly 5,000 years ago and was buried in a cemetery near Rakhigarhi, India, also suggest that the Indus Valley developed farming independently, without major migrations from neighboring farming regions. It’s the first time an individual from the ancient Indus Valley Civilization has yielded any DNA information whatsoever, enabling researchers to link this civilization both to its neighbors and to modern humans.

The Indus Valley, or Harappan, Civilization flourished between about 3300 B.C. and 1300 B.C. in the region that is now covered by parts of Afghanistan, Pakistan and northwestern India, contemporaneous with ancient Egypt and Mesopotamia. The people of the Indus Valley forged an impressively advanced civilization, with large urban centers, standardized systems of weights and measurements and even drainage and irrigation systems. Yet despite that sophistication, archaeologists know far less about the civilization than that of ancient Egypt or Mesopotamia, in part because the Indus Valley writing system hasn’t yet been deciphered.

Cracking Codes: 5 Ancient Languages Yet to Be Deciphered

a map of india, pakistan and afghanistan with sites where indus valley civilization archaeological finds havke been discovered

A map of the Indus Valley, or Harappan, Civilization. Rakhigarhi, the location of the burial that yielded ancient DNA for analysis, is highlighted in blue.

(Image credit: Vasant Shinde)

 Elusive DNA

Gathering ancient DNA from the Indus Valley is an enormous challenge, Vagheesh Narasimhan, one of the leading authors of the new research and a postdoctoral fellow in genetics at Harvard Medical School, Live Science, because the hot, humid climate tends to degrade DNA rapidly. Narasimhan and his colleagues attempted to extract DNA from 61 individuals from the Rakhigarhi cemetery and were successful with only one, skeleton likely belonging to a female which was found nestled in a grave amid round pots, her head to the north and feet to the south.

a round, red, chipped pot found in an ancient burial from the indus valley civilization

A red pot found near the head of the Indus Valley skeleton that yielded ancient DNA.

(Image credit: Vasant Shinde)

The first revelation from the ancient gene sequences was that some of the inhabitants of the Indus Valley are connected by a genetic thread to modern-day South Asians. “About two-thirds to three-fourths of the ancestry of all modern South Asians comes from a population group related to that of this Indus Valley individual,” Narasimhan said.

Where the Indus Valley individual came from is a more difficult question, he said. But the genes do suggest that the highly agricultural Indus people were not closely related to their farming neighbors in the western part of what is now Iran.

“We were able to examine different associations between the advent of farming in that part of the world with the movement of people in that part of the world,” said Narasimhan.

Farming, Narasimhan said, first began in the Fertile Crescent of the Middle East around 10,000 years ago. No one knows precisely how it spread from there. Did agriculture pop up independently in areas around the globe, perhaps observed by travelers who brought the idea to plant and cultivate seeds back home? Or did farmers move, bringing their new agricultural lifestyle with them?

In Europe, the genetic evidence suggests that the latter is true: Stone Age farmers introduced Southern Europe to agriculture, then moved north, spreading the practice as they went. But the new Indus Valley genetic evidence hints at a different story in South Asia. The Indus Valley individual’s genes diverged from those of other farming cultures in Iran and the Fertile Crescent before 8000 B.C., the researchers found.

“It diverges at a time prior to the advent of farming almost anywhere in the world,” Narasimhan said. In other words, the Indus Valley individual wasn’t the descendent of wandering Fertile Crescent farmers. She came from a civilization that either developed farming on its own, or simply imported the idea from neighbors — without importing the actual neighbors.

Both immigration and ideas are plausible ways to spread farming, Narasimhan said, and the new research suggests that both happened: immigration in Europe, ideas in South Asia. The results appear today (Sept. 5) in the journal Cell.

Complex populations

The researchers also attempted to link the Indus Valley individual to his or her contemporaries. In a companion paper published today in the journal Science, the researchers reported on ancient and modern DNA data from 523 individuals who lived in South and Central Asia over the last 8,000 years. Intriguingly, 11 of these people — all from outside the Indus Valley — had genetic data that closely matched the Indus Valley Individual. These 11 people also had unusual burials for their locations, Narasimhan said. Together, the genetic and archaeological data hint that those 11 people were migrants from the Indus Valley Civilization to other places, he said.

However, these conclusions should be viewed as tentative, warned Jonathan Mark Kenoyer, an archaeologist and expert on the Indus Valley Civilization at the University of Wisconsin, Madison, who was not involved in the new research. Archaeological evidence suggests that Indus Valley cities were cosmopolitan places populated by people from many different regions, so one person’s genetic makeup might not match the rest of the population. Furthermore, Kenoyer said, burial was a less common way of dealing with the dead than cremation.

“So whatever we do have from cemeteries is not representative of the ancient populations of the Indus cities, but only of one part of one community living in these cities,” Kenoyer said.

And though the Indus individual and the 11 potential migrants found in other areas might have been related, more ancient DNA samples will be needed to show which way people, and their genes, were moving, he said.

Narasimhan echoed this need for more data, comparing the cities of the Indus Valley to modern-day Tokyo or New York City, where people gather from around the world. Ancient DNA is a tool for understanding these complex societies, he said.

“Population mixture and movement at very large scales is just a fundamental fact of human history,” he said. “Being able to document this with ancient DNA, I think, is very powerful.”

Originally published on Live Science.

U.S. military brings back remains from World War II battle of Tarawa

(THIS ARTICLE IS COURTESY OF THE JAPAN TIMES)

 

NATIONAL / HISTORY

U.S. military brings back remains from World War II battle of Tarawa

AP

The U.S. military has brought back the remains of more than 20 servicemen killed in one of the bloodiest battles of World War II.

An Air Force cargo plane flew the remains from Tarawa atoll in the remote Pacific island nation of Kiribati (KEE-ree-bas) to Hawaii on Wednesday. Marines carried flag-draped caskets off the plane for a ceremony.

The remains are among those discovered in March by History Flight, a nonprofit organization that searches for the remains of U.S. servicemen lost in past conflicts.

They’re believed to belong to Marines and sailors from the 6th Marine Regiment who were killed during the last night of the three-day Battle of Tarawa. More than 6,000 Americans, Japanese and Koreans died.

Forensic anthropologists with the Defense POW/MIA Accounting Agency will work to identify the remains using dental records, DNA and other clues.

Blue Sky Science: What is gene editing?

(THIS ARTICLE IS COURTESY OF THE RACINE WISCONSIN JOURNAL TIMES)

 

Blue Sky Science: What is gene editing?

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Q What is gene editing?

— Ed Williams, associate fellow at Monsanto Co.

A Krishanu Saha, assistant professor, biomedical engineering and medical history and bioethics, University of Wisconsin-Madison:

Editing genes involves changing the sequence of letters in the DNA. Researchers like to edit genes so they can understand the function of them, particularly genes that relate to various types of disorders that physicians have seen in the clinic. We can use this information to generate new hypotheses of how genes influence diseases.

Historically, editing the genome has been difficult. Several editing technologies go into cells and essentially use “genetic scissors” to cut up the DNA. Once you introduce a cut into the genome, repair processes will try to repair that break. This repair often occurs in imprecise ways that could potentially cause errors and mutations.

Instead, you could take advantage of those repair processes to have the genome incorporate a foreign piece of DNA that has the letters that you want to be inserted.

Such editing has been done in human cells for the last 15-20 years using a set of proteins called nucleases. Nucleases are engineered proteins that cut DNA.

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Recently, the Cas9 nuclease, part of the CRISPR system, has really accelerated the pace of editing throughout biology and engineering.

To give you a frame of reference, about 10 years ago it cost about $50,000 to make only one precise cut in the genome. Attaining high precision was challenging: essentially finding a needle in a haystack, meaning editing one stretch of letters among 3 billion letters in the human genome. Understandably that was hard, and it took a lot of work to engineer the nucleases.

In the years since then, with the advent of the CRISPR system, a component called a guide RNA is used to attain precise editing. It’s easy to make the guide RNA, and this enables us to easily go after multiple parts of the genome at once. These components can be made very quickly on the order of a few dollars rather than thousands of dollars, making the technology more accessible for research.

Blue Sky Science is a collaboration of the Wisconsin State Journal and the Morgridge Institute for Research.

Here’s what Elizabeth Warren’s DNA test shows: She Does Have Some Native Blood

(THIS ARTICLE OS COURTESY OF THE NEW YORK POST)

 

Here’s what Elizabeth Warren’s DNA test shows

She has Native American in her family tree going back generations, according to a report Monday.

Carlos D. Bustamante, a Stanford University professor and expert in the field, determined in his analysis that a pure Native American ancestor appears in Warren’s family “in the range of 6-10 generations ago,” the Boston Globe reported.

That’s consistent with the Massachusetts Democrat’s family lore from her Oklahoma upbringing that her great-great-great-grandmother, O.C. Sarah Smith, was partially Native American.

Bustamante, who won a 2010 MacArthur Fellowship, also known as a Genius Grant, found that the “vast majority” of Warren’s ancestry is European, but “the results strongly support the existence of an unmixed Native American ancestor.”

The release of the DNA findings appear to be a way for Warren, who is expected to run for president in 2020, to put the issue to rest and remove a talking point for her opponents.

In a video posted on her website that begins with Trump calling her “Pocahontas,” Warren is speaking to Bustamante.

“Now, the president likes to call my mom a liar. What do the facts say?” she asks him.

“The facts suggest that you absolutely have a Native American ancestor in your pedigree,” he replies.

Tamping down accusations made by many Republicans that she parlayed her heritage to benefit her career, the video includes a number of law professors — including from Harvard Law and the University of Pennsylvania Law School — attesting that she was hired for her ability.

“Her heritage had no bearing on her hiring. Period,” Jay Westbrook, a professor at the University of Texas Austin School of Law, says in the video.

Warren also includes family members in the video who call out Trump for mocking her.

“He’s talking about stuff he doesn’t have any idea about,” says her nephew Mark Herring.

Warren herself also addresses Trump’s “Pocahontas” comments, saying “my family history is my family history.”

“This isn’t just about casual racism — war-hoops and tomahawk chops. Native Americans have faced discrimination, neglect and violence for generations,” she says in the video. “And President Trump can say what he wants about me, but mocking Native Americans or any group in order to get at me — that’s not what America stands for.”

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Will Churches And Parents Ever Quit Lying To Children About Christmas?

Will Churches And Parents Ever Quit Lying To Children About Christmas?

 

This post today is about one main issue; Santa Clause. I am not saying that all parents, Christian or not, lie too their children and tell them that there is really a Santa and flying Reindeer. But at least here in America it does seem that this fantasy is one that is easy to go along with when your children are in the 3, 4, 5-year-old range. But, there reaches a point with every child where they find out that Mom and Dad have been lying to them all of their life. Why, why do so many parents ‘just go along with this’ until we reach a point where our kids are going to realize that Mom and Dad will lie to you because they have proven themselves to be liars. I have heard people a few times in my life say ‘not to ruin Christmas’ for the young kids by telling them that there is no Santa. What do they mean by ‘ruin Christmas’? If you take Santa out of Christmas what would the children have then? How about the truth? Tell your kids the Christmas birth of celebration of a baby child call Jesus. Even if you do not believe in the Christian faith letting your children know what the truth behind the question, why is there such a thing as Christmas? Even if you are Jewish, Islamic, Hindi, Buddhist, or of no faith at all, do you really want one of the first lessons your child learns about you is that you lie to them? Why can’t people just be truthful with each other, is it truly in our DNA to be liars?

 

In this paragraph I am calling out not just Christian parents but some of the Churches themselves. I have seen and heard first hand of community Churches where even the Pastor is the one who dresses up as Santa for plays inside the Church building. I may be old-fashioned in some of your eyes, but so be it. I know that no one can please everyone, even Jesus was/is hated, so I have learned to only concern myself with trying to please Jesus, then let all of life’s other cards just fall where ever they fall. I personally would like to know how telling our children the ‘Jesus story’ ‘ruins Christmas’? What is wrong with telling your kids that you took a part-time job this fall so that you could have the money to buy your kids a few things extra at Christmas school break? What is wrong with your kids seeing the correlation between how hard Mom and Dad are working so that their kids can have a good Christmas? Is it wrong if our small children learn of the ‘3 wise man’ whom brought gifts to the new-born child as a model for people giving gifts to their own children? Why do so many people whom call themselves Christians have Santa and crew on their front lawns? Why do some Churches do the same? Truth, what is truth? There is only one ‘Truth’, and it is not your version, or mine. We can make-up and say anything, we can call our stories ‘the truth’ if we want to but if we are not telling the actual truth, then the word for us is liars. Now, is Santa real, or is he a lie? What are we telling our children, the truth, or lies?

Researchers finally solve mystery of ‘alien’ skeleton

(THIS ARTICLE IS COURTESY OF CNN)

 

Researchers finally solve mystery of ‘alien’ skeleton

The mummified specimen from Atacama region of Chile.

Story highlights

  • An unusual skeleton found in Chile has perplexed people for more than a decade
  • Whole genome sequencing revealed what caused its abnormalities

(CNN)A mummified skeleton discovered in Chile’s Atacama Desert 15 years ago doesn’t look like anyone you’ve ever met. In fact, some would say it looks, well, alien.

It’s a skeletal conundrum made up of perplexing features. It’s only 6 inches tall — but initial estimates of the age of the bones were consistent with a child aged 6 to 8 years.
The long, angular skull, slanted eye sockets and fewer than normal ribs — 10 pairs rather than the normal 12 — only deepened the mystery.
Questions surrounding the discovery led to speculation that it was a previously unidentified primate or even an extraterrestrial life form.
The skeleton, dubbed Ata, was featured in TV shows and a documentary, “Sirius,” in which a UFO researcher attempts to figure out Ata’s origins.
Now, the authors of a study based on five years of genomic analysis want to set the record straight: Ata is human, albeit one with multiple bone disease-associated mutations. And they believe that their findings, published Thursday in the journal Genome Research, could help diagnose genetic mutation-based cases for living patients.

Investigating Ata

In 2003, Ata was found in a deserted mining town called La Noria, in Chile’s Atacama region. It was thought to be ancient at first, but initial analysis conducted in 2012 proved that the skeleton was only about 40 years old. This meant DNA would still be intact and could be retrieved for study.
The widespread speculation surrounding Ata brought the case to the attention of Gary Nolan, senior author of the new study and professor of microbiology and immunology at Stanford University.
“I learned about this through a friend who was interested in the entire area of extraterrestrial life,” Nolan wrote in an email. “He told me about a documentary coming out (‘Sirius’ … you can find it on Netflix now) which was to feature the ‘Atacama Humanoid.’
It was claimed that this was possibly the mummy of an alien.
“That was a significant claim in and of itself. More shocking though was the picture I was provided that was part of the online publicity. I decided to contact the movie directors (basically on a dare …) to tell them it was possible to do a sequencing of the specimen (if it had earthly DNA …) to determine its origin.”
Nolan and his colleagues signed a confidentiality agreement, and the directors agreed to report Nolan’s findings, even if the results indicated that Ata’s DNA was human.
Nolan wanted to study Ata for several reasons. The extraordinary specimen could have been a previously unrecognized primate species, some sort of human deformity or something else entirely. Nolan said he and his colleagues never believed it could be an alien.
They wanted an answer to the basic question: “What is it?”
DNA analysis would tell the true story. A sample extracted from the bone marrow of Ata’s ribs was used to conduct a whole-genome sequence analysis.
It was compared with human and primate genomes and determined to be a human female, probably a fetus, with Chilean ancestry. Although dating initially estimated the bone age of the skeleton at between 6 and 8 years, the researchers found that the remains had a rare bone-aging disorder that made them seem older than the person they belonged to.
At first, 8% of the DNA didn’t match with human DNA. Researchers determined that this was because of a degraded sample. An improved analysis matched up to 98%, Nolan said. Given the exposure and age of the skeleton, this wasn’t surprising. Then, they moved on to diagnosing the abnormalities.

It’s all in the genes

The researchers were looking for what might explain the skeleton’s small stature, as well as the abnormal rib count and other bone and skull oddities.
Dr. Atul Butte, another senior author of the study, was brought in to assist with evaluating the genome. Butte, the Priscilla Chan and Mark Zuckerberg distinguished professor and director of the Institute for Computational Health Sciences at the University of California, San Francisco, treated the analysis as though it were for a patient.
It revealed a number of mutations within seven genes. Together, these created bone and musculoskeletal deformities, like scoliosis, and skeletal dysplasia, known as dwarfism.
“There are mutations in many genes, including genes involved with the production of collagen (in our bones and hair), joints, ribs, and arteries,” Butte wrote in an email. “We know these genes are involved with these processes in human development, but we are still learning what all the other genes in the DNA do.”
Although the mutations found within the genes are known to cause bone disease, some of them had not been previously connected to growth or developmental disorders. The combination of genetic mutations explains Ata’s appearance, but it’s the number of mutations all present in the same specimen that surprised the scientists.
“It’s rare,” Butte said. “To our knowledge, no one has ever explained all of these symptoms in a patient before, and the changes in the DNA, or mutations, reflects this.”
But what could have caused this number of mutations?
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“Many times, genetic diseases are passed on from parents that are carriers,” Butte said. “In this case, these mutations are so rare that we haven’t actually ever seen some of these before, so it’s hard to imagine there are carriers out there. We do speculate that the environment where this child was developing might have played a role. The specimen was found in a town with abandoned nitrate mines, and exposure to nitrates might have caused the mutations. But it’s only speculation.”
No other researchers have seen the remains.
The way Nolan, Butte and their colleagues used their analytical tools to understand the mysteries presented by Ata’s skeleton may provide a pathway for analysis of multiple genes to discover the roots of mutations.
Butte said he hopes that the technology and tools used in this study can help patients and their families receive diagnoses quicker, as well as helping to develop treatments for conditions that can be traced to genetic mutations.
“Many children’s hospitals now see patients or children with unusual syndromes, including those never described before,” Butte said.
“DNA sequencing is now more commonly used to help us solve these ‘undiagnosed diseases.’ But many times, we tend to search for a single gene mutation that might explain what we see in the patient.
“What this case taught me we that sometimes there might actually be more than one major DNA difference involved in explaining a particularly hard-to-explain patient. We shouldn’t stop a search when we’ve found the first relevant mutation; indeed there might be many others also involved.”

Neanderthals And Denisovan’s Were Mixing With Homo Sapiens

(THIS ARTICLE IS COURTESY OF CNN)

 

Neanderthals, Denisovans and our ancestors were mixing and mingling a long time ago — and some of our genetics can be traced back to these archaic humans.

In Asians, as much as 3% of an individual’s DNA may be Neanderthal. For Europeans, it’s as much as 2%. A new study has found that our ancestors interbred with two distinct Denisovan populations, increasing the probability of the presence in modern populations of DNA inherited from this ancient and mysterious people.
The study, using a new genome-analysis method to compare whole genomes of humans with Denisovans, was published in the journal Cell on Thursday.
“It is amazing that we can look into human history via current-day human genetic data, and determine some of the events that happened in the past,” study author Sharon Browning wrote in an email. Browning is a research professor with the University of Washington’s Department of Biostatistics.
“In particular, in this study we found two distinct episodes of Denisovan admixture, which adds to what was previously known about the contribution of Neanderthals and Denisovans to our genomes today.”

Denisovans pose questions

Denisovans pose particular questions for scientists because researchers have only a few bones that even point to their existence: a finger bone, toe bone and a couple of teeth. Fossilized DNA sequenced from those bones, recovered in Siberia, has allowed us to learn more about them. But we still don’t know what these extinct hominins looked like.
Neanderthal and Denisovan DNA was sequenced completely for the first time in 2010, which led to the initial discovery that they were interbreeding with our ancestors. Studies found that the population of Oceania and Papua New Guinea received the most DNA from Denisovans, around 5%.
Fifty thousand years ago, as modern humans moved out of Africa, they encountered Neanderthals and Denisovans, and the “admixing” happened. But pinning down exactly where it happened has proved difficult.
It was especially puzzling given that the fossils were found in Siberia, but Denisovans are most strongly connected to Oceania.
Denisovan ancestry was also present in Asia, although researchers believed that this occurred through migration from Oceania.
Comparing the Denisovan genome to that of 5,600 Europeans, Asians, Americans and Oceanians painted a different picture.
The data showed that Denisovans were even more closely related to modern East Asians, specifically Han Chinese, Chinese Dai and Japanese, than those from Papua New Guinea. And this second set of Denisovan ancestry was different from Oceanians and Papuans.
“It makes it clear that there were distinct populations of Denisovans, rather than a single population,” Browning said. “The fact that these populations had diverged somewhat from each other suggests that the two populations were not mixing very often with each other, perhaps due to geographical separation.”
A possible explanation is that our Oceanian ancestors encountered a southern group of Denisovans, while East Asians met a northern group.
“(This) led people to suspect that Denisovans did not just live in Siberia, but also lived elsewhere in Asia, somewhere south along the likely routes that the ancestors of Oceanians may have taken to get to Oceania,” Browning said. “This study makes this hypothesis look very likely.”
This could also mean that there were more than two distinct episodes of Denisovans mixing with modern humans, which Browning believes future analysis could reveal.
“A major novel finding is that some populations (East Asians) have evidence of multiple introgression related to Denisovans while a few others (South Asians, Papuans) have evidence of a single Denisovan introgression,” Sriram Sankararaman said in an email. “The Denisovan ancestry in South Asians is quite diverged from the sequence Denisovan while the additional component in East Asians is quite close. This suggests a complex interaction pattern of the Denisovans and modern human populations in mainland Asia.”
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Sankararaman, who was not involved in the study, has worked on Denisovan research and is an assistant professor at the University of California, Los Angeles, in the department of computer science and the department of human genetics.
Going forward, Browning and her colleagues plan to study other populations to look for signatures of admixture with archaic humans besides Neanderthals and Denisovans.
“I’d love to delve further into Neanderthal ancestry, and understand why East Asians have a higher rate of Neanderthal ancestry — around 3% — compared to Europeans — around 2%,” Browning said.
“It has been hypothesized that the extra Neanderthal ancestry in East Asians is due to an additional admixture event, but we didn’t find a clear sign of that in our study. That doesn’t rule out this possibility — we might need to dig a little deeper to find it.”

Who Do You Consider To Be Your Family

Who Do You Consider To Be Your Family

 

Who do you consider your family to be? I know from raising this subject within small groups that people have a wide variety of answers to that simple question. Some people only feel that their immediate household is their family, you know, Mom, Dad, and siblings. I have met quite a few people who have even divorced some of or all of those people from their lives. I have met many people who are by blood siblings or parents of friends that I know well, whom when you met them you see why your friends have no use for this or that blood relative. When I was growing up I was inundated by alcoholics who were also close blood and of course those they chose to hang around and guzzle the suds with. These days it seems that drugs like crack and meth are the vehicle which is totally ripping families apart. When people get hooked on those chemicals they usually find themselves unemployed and homeless when they have used up all of their friends and family because they will steal from anyone to get another high. After a while even close family members tell them to never darken their doorway again. Of course there are many other reasons also that causes families to fall apart, to me, either which way you look at this issue it is sad when brother won’t speak to his brother, or parent to child.

 

 

My wife as well as a few other people throughout my life have told me they think I’m nuts because to me once you are family, you are always family. I have at times joked that I must have some Italian blood in my veins because of how I feel about this issue. I know that I don’t, my tree just goes back to Norway, Ireland, Scotland, and England so I’m just a Scandinavian area mutt. The only brother that I ever knew (one brother died before I was born) was married three times before he died from an aneurysm at the age of 43. He was seven years older than me and so he was out whoring around well before I was. Each of the three ladies that he married already had kids when he married them. He had one child with each of them but there were/are 18 kids that weren’t his. Don’t think that I am trying to get uppity on my brother now because I myself have been married three times also. Total I have two blood kids of my own and I have two-step kids that to me are my kids as if they were blood, I love all four of them. They are all four grown and I have seven grand-kids now, I consider myself to be a very fortunate person.

 

 

About everyone I know thinks we have got this in our DNA of caring, or we don’t. I am from a small core family of five, so to me once a person or persons are family, you are always family. Should I not speak with former in-laws of my own or of my brother just because of a divorce? Do you just stop communicating with people that you grew to love as if they just don’t matter anymore? To me it is difficult to stop loving someone who you have honestly loved. You see, to me all of my brothers kids and step kids are my nephews and nieces and they always will be, just as his three x-wives will always be sisters to me.

 

 

What is your opinion on my line of thoughts and beliefs about family? Do you think I am just plain odd that I would count people as family the way I do? What is your opinion on whom you consider to be in your heart? I have met a few people who when they got old enough to get out on their own they totally divorced themselves from everyone they knew usually because of how they were treated in their growing up years. To me that would be a sad personal situation for any person to be in but I have also know of parents who put their kid on the street and told them to never come to their door again. It is sad for people to have such splits in their lives, it really doesn’t surprise me why many people only consider people who are not blood, to be their real family. Well, if you would, drop me a line on your thought’s of what or who, that you consider to make up a family. Thank you for your time, I appreciate you stopping in. Goodnight and God’s blessings I pray for you and your family, (inner circle).—Oldpoet56

 

First human eggs grown in laboratory

(THIS ARTICLE IS COURTESY OF THE BBC)

 

First human eggs grown in laboratory

Media caption‘It could be of huge benefit to children having cancer treatment’

Human eggs have been grown in the laboratory for the first time, say researchers at the University of Edinburgh.

The team say the technique could lead to new ways of preserving the fertility of children having cancer treatment.

It is also an opportunity to explore how human eggs develop, much of which remains a mystery to science.

Experts said it was an exciting breakthrough, but more work was needed before it could be used clinically.

Women are born with immature eggs in their ovaries that can develop fully only after puberty.

It has taken decades of work, but scientists can now grow eggs to maturity outside of the ovary.

It requires carefully controlling laboratory conditions including oxygen levels, hormones, proteins that simulate growth and the medium in which the eggs are cultured.

‘Very exciting’

But while the scientists have shown it is possible, the approach published in the journal Molecular Human Reproduction still needs refinement.

It is very inefficient with only 10% of eggs completing their journey to maturity.

And the eggs have not been fertilised, so it is uncertain how viable they are.

Prof Evelyn Telfer, one of the researchers, told the BBC: “It’s very exciting to obtain proof of principle that it’s possible to reach this stage in human tissue.

“But that has to be tempered by the whole lot of work needed to improve the culture conditions and test the quality of the oocytes [eggs].

“But apart from any clinical applications, this is a big breakthrough in improving understanding of human egg development.”

UK scientists edit DNA of human embryos

First monkey clones created in the lab

First three-parent baby born to infertile couple

Human EggImage copyrightUNIVERSITY OF EDINBURGH
Image captionA lab-grown, human egg made by scientists at the University of Edinburgh

The process is very tightly controlled and timed in the human body – some eggs will mature during the teenage years, others more than two decades later.

An egg needs to lose half its genetic material during development, otherwise there would be too much DNA when it was fertilised by a sperm.

This excess is cast off into a miniature cell called a polar body, but in the study the polar bodies were abnormally large.

“This is a concern,” said Prof Telfer. But it is one she thinks can be addressed by improving the technology.

Work on mouse eggs, which was nailed 20 years ago, showed the technology could be used to produce live animals.

Matching this achievement in human tissue could eventually be used to help children having cancer treatment.

Cancer option

Chemotherapy and radiotherapy risks making you sterile.

Women can freeze matured eggs, or even embryos if they are fertilised with a partner’s sperm, before starting treatment – but this is not possible for girls with childhood cancers.

At the moment they can have ovarian tissue frozen before treatment, which is then put back in to mature years later if the patient wants children of their own.

But if there are any abnormalities in the frozen sample then doctors will think it is too risky.

Being able to make eggs in the lab would be a safer option for those patients.

Mr Stuart Lavery, a consultant gynaecologist at Hammersmith Hospital, said: “This work represents a genuine step forward in our understanding.

“Although still in small numbers and requiring optimisation, this preliminary work offers hope for patients.”

It would be legal to fertilise one of the lab-made eggs to create an embryo for research purposes in the UK.

But the team in Edinburgh do not have a licence to carry out the experiment. They are discussing whether to apply to the embryo authority for one, or collaborate with a centre that already has one.

Prof Azim Surani, the director of germline research at University of Cambridge’s Gurdon Institute, said: “Molecular characterisation and chromosomal analysis is needed to show how these egg cells compare with normal eggs.

“It might be of interest to test the developmental potential of these eggs in culture to blastocyst stage, by attempting IVF.”

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