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One of the most infamous emperors of Chinese antiquity was the very first: Qin Shi Huang.  
Also known as Ying Zheng, he ruled the Chinese state of Qin from 247-210 BC.  When he came to power, various Chinese kingdoms were engaged in a struggle against each other for superiority; by the time he died in 210 BC, he had managed to unify these warring states, becoming the First Emperor of China and ushering in the Qin Dynasty.
<h6>The Great Wall</h6>
Under the rule of Qin Shi Huang, massive construction projects were undertaken to help build the infrastructure needed in imperial China, often at the expense of many lives.  
The first version of the Great Wall of China was built during this period, as was the first national road system.
<h6>A Mausoleum</h6>
But the most famous remnant of Qin Shi Huang’s rule was his mausoleum in the Shaanxi province of central China.  
Construction began in 246 BC – in addition to the tomb that would house the body of the emperor, there were large palaces, valuables, rivers flowing with mercury, and scenes of the earth and sky painted on the ceiling.  
<h6>An Army of Clay</h6>
But the most spectacular feature of the mausoleum was the emperor’s guards:   the Terracotta Army.   These 8,000 soldiers, crafted using molds and clay, stand guard over the Emperor Qin’s tomb so they may aid him in the afterlife.
The construction of the mausoleum, like other construction projects during the emperor’s rule, involved a huge workforce.   An estimated 700,000 workers were involved in the mausoleum construction alone.
<h6>Who Built the Terracotta Army</h6>
Until now the identity of these workers has remained a mystery, but a study published last week in <a id="mg1z" title="PLOS ONE" href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0003275" target="_blank" rel="noopener noreferrer">PLoS ONE</a> has attempted to discover who these workers were by examining the DNA preserved in their bones.
In 2003, hundreds of skeletal remains were unearthed near the mausoleum.   They were believed to be the remains of the workers who built the monument, and a preliminary examination of their bones revealed that these men were engaged in heavy manual labor up to their death. But due to poor preservation of the remains, scientists could not determine the ethnic origins of these workers.   Since the Qin Dynasty controlled a vast territory and encompassed 22 million people, these workers could have come from anywhere. 
<h6>Follow the Mito</h6>
So Chinese scientists decided to examine the mitochondrial DNA of these workers directly to discover their ethnic origins.
These scientists started by collecting DNA samples from 50 thigh bones for analysis.   Because ancient DNA analysis is prone to contamination, the researchers took extreme precautions in performing their analysis.   In the end, the state of decay of the samples meant the DNA of only 19 individuals could be analyzed.
What the researchers found was that these workers had come from a variety of places across East Asia.   In fact, the 19 individuals fell into 16 unique maternal haplogroups.   The most common haplogroup was N9a, which is thinly spread throughout central and eastern Asia today.   Other maternal haplogroups represented included M8a, A, and D5, which are all present among East Asian populations today.
<h6>Origins</h6>
Only four of the 19 specimens could be considered ethnically Han, which is the most common ethnic group in China today.   Interestingly, seven individuals came from southern China, and a smaller number came from northern China.   One individual even carried the maternal haplogroup usually seen only among certain Japanese populations, M7a.
The authors conclude that the overall diversity of mitochondrial genetic types seen in these 19 individuals indicates that workers were taken from across China, something that is also asserted in historical records from the period.   While further analysis of a greater number of remains is necessary, this initial study has shown that workers from all parts of the burgeoning Qin Empire may have taken part in building some of the first structures of Imperial China.

23andMe Blog

23andMe Blog Team

Who Built the Terracotta Army? The Genetic Origins of the Qin Dynasty Mausoleum Workers

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Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the western world among people over 60. The two forms of the disease — wet and dry — both cause vision loss by destroying cells in the central portion of the retina.
<h6>Genetic Associations</h6>
In the last few years, progress in understanding AMD has been made thanks in part to the discovery of several common genetic variants, or SNPs, that together explain a large part of the risk for the disease. Several of these recently discovered genetic associations have pointed to a role for the immune system in the disease.
A new study published online Monday in <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140673608613483/abstract?isEOP=true" target="_blank" rel="noopener noreferrer">The Lancet</a> yet again links the immune system to AMD. As is the case for several of the previously found SNPs, the variant found in this study is in a gene involved in the complement pathway, an arm of the immune system that facilitates the elimination of both pathogens and cellular debris.
<h6>Making a Connection</h6>
Many years ago some researchers suspected that the complement system might be involved in AMD. Proteins from this pathway were found in drusen, the small crystalline deposits that build up in the eyes of people with AMD. But it was not until genetic studies started to show a link between AMD and complement genes that other scientists began to sit up and take notice.
In two separate samples &#8212; one British with 479 AMD patients and 479 controls, the other from the U.S. with 248 cases and 252 controls &#8212; Ennis et al found that the odds of developing AMD were reduced for those with on variant in the SERPING1 gene, which encodes a protein that regulates the complement pathway.
“Our findings add to the growing understanding of the genetics of age-related macular degeneration, which should ultimately lead to novel treatments for this common and devastating disease,” the authors write.
In an accompanying comment in The Lancet, Caroline Klaver and Arthur Bergen, two scientists not associated with the research, said the results of Ennis et al need to be replicated in large, independent samples before SERPING1 will be established as a true risk factor for AMD. They also suggest that the researchers may find other SNPs within the gene that are even more tightly linked to AMD.

SNPwatch: AMD Linked to Yet Another Immune System Gene

<img loading="lazy" decoding="async" width="275" height="347" class="alignright size-full wp-image-1548" title="doc_hollidayatage20" src="https://blog-api.23andme.com/wp-content/uploads/2008/10/doc_hollidayatage20.jpg" alt="" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/10/doc_hollidayatage20.jpg 275w, https://blogcms.23andme.com/wp-content/uploads/2008/10/doc_hollidayatage20-238x300.jpg 238w" sizes="auto, (max-width: 275px) 100vw, 275px" />John Henry &#8220;Doc&#8221; Holliday is rumored to have been born with a cleft lip and palate.
Beginning in the fourth week of gestation, the cells of a developing human fetus begin a complex program of rearrangements to form what will eventually become a child’s face.
In about one out of every 700 births this process goes awry. Genetic and environmental factors, acting alone or in concert, prevent the cells of the face from coming together properly, resulting in cleft lip and/or cleft palate. Though clefting can cause problems with feeding, ear infections and tooth development, surgery and other treatments can allow children to grow up to lead perfectly normal lives.
<h6>Genetic Associations</h6>
Although there are some rare genetic syndromes that cause cleft lip and/or palate, most cases of clefting are probably due to a combination of genetic factors and environmental triggers. Those environmental factors include exposure to certain infections, some medications, alcohol and drug use, cigarette smoking, and certain vitamin deficiencies, especially during early pregnancy.
Fedik Rahimov and colleagues have now found the first common genetic variant strongly associated with a cleft lip. Their results, published in <a href="https://dx.doi.org/10.1038/ng.242" target="_blank" rel="noopener noreferrer">Nature Genetics</a>, show that the common, non-inherited form of this condition is linked to a gene called IRF6 that was previously associated with a rare, dominantly inherited clefting disorder called Van der Woude syndrome.
<h6>The Study</h6>
Using 280 European families affected by cleft lip only, the researchers found a variant that was associated with an 1.91 times increase in the risk, while another variant increased the risk by 2.29 times.
Approximately 50% of people born with cleft lip also have a cleft palate. Having cleft palate alone (no cleft lip) is rare, and there was no evidence the genetic variant associated with a cleft palate is associated with having a cleft lip.
The authors note that variant they identified is least commonly found in Africans and most common in Native Americans, which mirrors the different levels of cleft lip and palate found in these populations. Because this research was conducted in Europeans, determining whether this SNP is associated with cleft lip in these populations will require further research.

Genetic Variant Linked to Cleft Lip

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Before efforts to sequence the human genome began, scientists thought they’d find about 100,000 protein-coding genes in the three billion bases pairs of DNA that are found in almost every cell.
But much to everyone’s surprise, the true number turned out to be much lower. It’s now thought that the human genome contains only about 20,000 protein-coding genes, representing less than 2% of the contents of the genome.
<h6>Ultraconserved Elements</h6>
Much of the remaining 98% of the genome remains a mystery. Some chunks of this DNA are referred to as “ultraconserved elements” because they have remained practically unchanged through hundreds of millions of years of evolution in many species.
It is a basic principle of biology that if something goes unchanged for that long, it ought to be good for something. Yet the function of ultraconserved elements is completely unknown. In fact, laboratory studies in mice have shown that the animals <a href="http://biology.plosjournals.org/perlserv/?request=get-document&#038;doi=10.1371/journal.pbio.0050234&#038;ct=1" target="_blank" rel="noopener noreferrer">do just fine</a> when some of the ultraconserved elements are deleted.
<h6>Humans and Macaques</h6>
To find out if ultraconserved elements really are dispensable, Cory McLean and Gill Bejerano of Stanford University analyzed ultraconserved elements and non-conserved DNA sequences in five mammalian genomes.
Their results, published online today in <a href="https://genome.cshlp.org/cgi/content/abstract/gr.080184.108v1" target="_blank" rel="noopener noreferrer">Genome Research</a>, show that regions of DNA that are identical or very similar between humans, macaques, and dogs are about 300 times less likely to be missing in rats and mice than regions that are not as closely conserved between the primate and dog species.
It’s not that ultraconserved regions are somehow protected from change. The researchers suggest that in the wild, mutations in these elements put affected animals at a disadvantage, causing the changes to be swept away over time by natural selection. But in the lab there isn’t a whole lot of natural selection – in an environment where mice are treated to filtered air, an absence of predators, and all the food and water they could ever want, any loss of fitness due to lost ultraconserved elements doesn’t seem to have any observable consequences.
<h6>What it might mean</h6>
McLean and Bejerano also found that DNA sequences that can be traced farther back in evolutionary time are more likely to be conserved in diverse species today.
“The longer the sequence has been in us, the less likely it is to be lost. It’s almost like the bricks in the foundation of a building, which hold up the rest of the structure,” said Bejerano in a statement.
Detailed new genome sequences from a variety of mammals will allow Bejerano’s research team to further analyze ultraconserved elements and perhaps ultimately understand what it is they are doing in the genome.
“Evolution is a lot of fun,” said Bejerano. “You answer one question, and five others pop up. But one of the most rewarding things to me is the fact that we’re developing a growing appreciation for how much these regions actually matter.”

The Mystery of Ultraconserved Elements

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23andMe is marking the 23rd anniversary of National Breast Cancer Awareness Month this October with an initiative to build a web-based forum dedicated to helping women who face the disease.
Co-founders Linda Avey and Anne Wojcicki told science and business leaders at Fortune&#8217;s Most Powerful Women Summit today that we will be creating a specific breast cancer network within 23andWe, the research division of 23andMe.
&#8220;Great strides have been made in targeting treatment for breast cancer,&#8221; said Linda Avey. &#8220;We&#8217;d like to build on this progress, and we believe that by creating a web-based forum that enables women to share their experiences, the entire community could benefit and more personalized treatments may ultimately be an outcome.&#8221;
Women whose lives have been touched by breast cancer will be able to come together, share their knowledge and offer advice. They will also have the opportunity to participate in surveys that will be used to drive genome-wide association studies aimed at finding out more about the genetic factors that contribute to breast cancer.
&#8220;Women who have been recently diagnosed with breast cancer can learn a tremendous amount from women who have already been treated,&#8221; said Anne Wojcicki. &#8220;By combining the ability to participate in research with the ability to learn from each other, 23andMe hopes to make a significant contribution to this community.&#8221; 

Breast cancer can affect both sexes, but it is mainly a concern for women–one in eight will face the disease at some point in her lifetime. The National Cancer Institute estimates that in 2008 about 182,500 women will be diagnosed with breast cancer, and close to 40,500 will succumb to the disease.
<ul>
<li>To learn more about breast cancer: 
<a href="http://www.cancer.gov/cancertopics/types/breast" target="_blank" rel="noopener noreferrer">National Cancer Institute </a> 
Susan G. Komen For the Cure</li>
<li>To learn more about 23andWe, click <a href="https://www.23andme.com/research/" target="_blank" rel="noopener noreferrer">here</a>.</li>
</ul>

23andMe Co-founders Announce Breast Cancer Initiative

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Once considered the wages of gluttony, new research suggests that gout may have as much to do with genetics as indulgence.
Gout occurs when high levels of uric acid in the bloodstream cause the substance to form crystals in the joints, leading to painful inflammation and the growth of nodules known as tophi. Anything that increases the production of uric acid or interferes with the body&#8217;s ability to dispose of it through the kidneys – including the consumption of protein-rich foods and alcohol – can aggravate the condition.
Anything that increases the production of uric acid or interferes with the body&#8217;s ability to dispose of it through the kidneys – including the consumption of protein-rich foods and alcohol – can aggravate the condition.
But researchers have learned recently that variations in a gene involved in the excretion of uric acid by the kidneys can also increase a person&#8217;s chances of developing gout. And now a study published this week in the medical journal The Lancet confirms that discovery and also associates two additional genes with the disease.

The study measured uric acid levels in nearly 12,000 people of European ancestry from the Netherlands and the United States. It identified three different single-letter genetic variations, known as SNPs, that were associated with differences in uric acid concentration.
Those SNPs also turned out to be associated with the chances that a person had gout.
And when the researchers tested their observation in a third U.S. population of nearly 14,000 whites and African Americans, they found that one of the three SNPs was also associated with gout among blacks.
All three SNPs were located in genes that are active in the kidneys and thought to be involved in uric acid excretion.
Though each of the three SNPs individually affected a person&#8217;s chance of having gout by less than a factor of two, the researchers point out that in one of their study populations the combination of all three had a 40-fold effect on a person&#8217;s risk for the disease.
That&#8217;s substantially higher than the effects of diet, obesity and other risk factors for gout, which affects less than one percent of the US population.

Three New Associations for Gout Strengthen Genetic Link

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The connection between <a href="http://www.cancer.gov/cancertopics/factsheet/risk/obesity" target="_blank" rel="noopener">obesity and cancer</a> is well established. As many as 25 to 30 percent of several major cancers — colon, breast (postmenopausal), endometrial, kidney, and esophagus — may be accounted for by obesity and physical inactivity. Some studies have also found links between obesity and cancers of the gallbladder, ovaries, and pancreas.
It is not yet clear to scientists, however, how obesity increases the risk for certain cancers. Part of the answer may lie in a hormone released by fat cells &#8212; adiponectin. Decreased blood levels of this hormone, which are found in obese people, have been <a href="https://www.ncbi.nlm.nih.gov/pubmed/18265479?ordinalpos=1&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum" target="_blank" rel="noopener">linked</a> with breast, endometrial, prostate and colon cancer.
A new study published today in the <a href="http://jama.ama-assn.org/cgi/content/full/300/13/1523" target="_blank" rel="noopener">Journal of the American Medical Association</a> provides further evidence for adiponectin being the link between obesity and cancer. Researchers have demonstrated that a variant in the gene that encodes the hormone influences the risk of developing colorectal cancer.
Kaklamani et al examined several SNPs in the adiponectin and adiponectin receptor genes in a total of 629 people with colorectal cancer and 855 people without the disease. All subjects except for 37 cases and 37 controls were of European ancestry. The researchers found that people with one or two Gs at rs266729 in the adiponectin gene had 27% lower odds of developing colorectal cancer compared to those with two Cs.
(23andMe customers can look up their data for rs266729 using the Browse Raw Data feature)
According to the report’s senior author, Dr. Boris Pasche, these research findings could help identify people who would benefit from increased colorectal cancer screening.

“Our hope is that we can significantly improve the screening and early detection for this disease, and open new avenues for better understanding the genetic and lifestyle factors that influence colon cancer risk, “ he said in a statement.
Pasche went on to caution that additional studies are needed to confirm whether those without the adiponectin variant that appears to protect people from colorectal cancer will benefit from cancer-prevention lifestyle changes such as diet and exercise.
A different variant in the adiponectin gene was recently identified as a <a href="https://www.ncbi.nlm.nih.gov/pubmed/18451143?ordinalpos=1&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum" target="_blank" rel="noopener">modifier of breast cancer</a> risk in a study co-authored by Pasche. Understanding how variants in this gene influence breast and colorectal cancer risk, and whether the variants affect the risk for other cancers, will require more research.
Colorectal cancer is the second-leading cancer killer of Americans. According to estimates from the American Cancer Society, 149,000 people will be diagnosed with the disease and 50,00 will die this year alone.

Genetic Link Between Obesity and Colorectal Cancer

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Researchers are sometimes frustrated when a prospective drug proves effective in some patients, but not enough to justify giving it to everyone who has the condition it is intended to treat.
The beta-blocker drug bucindolol met that fate in 2001 when it was originally tested as a treatment for heart failure. Though it did help a fraction of the 2,708 patients in the study, it didn&#8217;t improve the condition of enough patients to be approved for the market.
But <a href="https://online.wsj.com/article/SB122212399407465005.html?mod=googlenews_wsj">now</a> researchers have rescued bucindolol from the pharmaceutical dustbin by identifying a genetic variation that increases a person&#8217;s chances of benefiting from the drug. Researchers collected DNA samples from 1,040 patients who were involved in the original study, and found that genetics plays a significant role in determining its effectiveness. In light of the discovery, the company that owns the drug, <a href="http://www.arcabiopharma.com/">ARCA biopharma</a>, has <a href="http://www.fiercebiotech.com/press-releases/bucindolol-significantly-reduces-hospitalization-and-death-heart-failure-patients-v-0">applied to the FDA</a> for approval to sell it.

The most important gene in determining bucindolol&#8217;s effectiveness is ADRB1, which is not surprising – the gene is involved in activating the &#8220;fight or flight&#8221; response to the hormone adrenaline. Beta-blocker drugs such as bucindolol suppress that response, protecting a weak heart from the strain that an adrenaline response produces.
It appears that bucindolol blocks adrenaline&#8217;s effects only if a person has a particular form of the ADRB1 gene. Among those people, bucindolol decreased the risk of death from heart-related causes 48%.
23andMe customers can determine whether they have the form of ADRB1 that responds to bucindolol by checking their genotypes at the SNP rs1801253; the CC genotype is the responsive form of the gene. 23andMe customers and demo account holders can also read more about bucindolol in the Beta-blocker Response section of My Health and Traits.
Until now, the vast majority of drugs prescribed on the basis of genetics have been for cancer – and their effectiveness has mostly depended on the genetics of the tumor rather than the patient. But the bucindolol story illustrates the broader promise of genetic information for drug developers, physicians and patients. The hope is that eventually, understanding how genetic variations influence the effectiveness of drugs and their side effects will usher in a new era of personalized medicine.

Biotech Company Applies for FDA Permission to Market Gene-Targeted Heart Failure Drug

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What is it about humans that distinguishes us from the rest of the animal kingdom?   Is it our upright walking?   Our language?   Our love of Reality TV?   Even though we are said to be 99% genetically identical to our closest evolutionary relative, the chimpanzee, we clearly differ vastly from them physically and behaviorally.
For many years, scientists have attempted to understand how our species came to be so different from any other on the planet.   In the October issue of <a id="ikcg" title="Nature Reviews Genetics" href="https://www.nature.com/nrg/journal/v9/n10/abs/nrg2428.html" target="_blank" rel="noopener noreferrer">Nature Reviews Genetics</a>, scientists at the UCLA and the Howard Hughes Medical Institute examine recent research to understand how genetic mutations have set us apart from our nearest relatives. In addition, they discuss how these genetic changes relate to the vast array of physical and behavioral differences that also have to be considered to fully understand what makes our species so unique.
<h6> 
The 1% Difference</h6>
The authors begin their examination of human uniqueness by focusing on the overall genetic differences between our species and chimpanzees.   Many years ago, research revealed that humans and chimpanzees are remarkably similar in terms of both genetic and biochemical structure.   Scientists hypothesized that because the two species are so structurally similar, the differences between humans and chimps would turn out to be primarily in the way that genes — and therefore proteins — are expressed.   Further analysis confirmed that there is only a 1% difference in overall genetic and biochemical structure between the two species – a number many people still cite today.
However, the authors argue that more recent analysis has actually shown that deletions and duplications of DNA in both species bring the genetic difference between the two to about 4% across the entire genome.   These and other findings have, according to the authors, “dashed the hope that it would be simple to determine the key genetic differences between humans and closest evolutionary relatives, that is, the genomic aspects of ‘what makes us human’ ”.
Yet many recent breakthroughs in comparative genomics have identified human genetic features that may be unique.   Below are two examples:
<h6>MYH16</h6>
One key difference between humans and chimpanzees is the difference in brain size.   Humans have an average brain volume of about 1500 cm3, which is roughly three times the size of a chimp&#8217;s.   While having a comparatively large brain was one of the most important factors in the evolution of our species, it has also resulted in an organ that is very expensive to maintain.   In fact, many anthropologists have argued that in order for our large brains to have evolved, there must have been a simultaneous reduction in the size of other organ systems and muscle mass.
In 2004, scientists discovered a gene, MYH16 that may have been involved in that trade-off between increased brain size and decreased muscle mass.   Believed to be related to the growth of muscles in the jaw of chimpanzees and other apes, MYH16 has been mutated in humans so it remains switched off.   Scientists hypothesize that the gene&#8217;s lack of expression in humans causes an eight-fold reduction in the size of muscle fibers in the human jaw.   Interestingly, the timing of this mutation appears to have happened about 2 million years ago, when Homo erectus — the first of our fossil ancestors to exhibit a significant increase in brain size, evolved in Africa.
<h6>FOXP2</h6>
Sometimes referred to as &#8220;the language gene,&#8221; FOXP2 made a splash in the popular media when it was first described in 2002, because a very slight mutation in the human version is believed by some to have led to the evolution of language in humans.
FOXP2 is not unique to humans.   In fact, many species — including songbirds and alligators — have the gene, which is required for proper brain development.   Though the human FOXP2 gene is slightly different, it has been found to be related to vocal learning in birds, and may even be tied to the evolution of echolocation in bats.
In addition, new research has suggested that it may not be the FOXP2 gene itself, but rather a related genetic pathway, and it is that related gene that may be involved in the evolution of speech and language development in humans.   At the moment the exact relationship between FOXP2 and human language remains unresolved – an illustration of the genome&#8217;s complexity.
<h6>Genotype vs. Phenotype</h6>
The authors conclude their review by proposing a method of examining human uniqueness from a genomic perspective in light of the fact that “traditional evolutionary biology approaches have yet to explain most of the unique features of humans.”   They argue that in order to move the field of evolutionary genomics forward, and to truly understand what it means to be ‘human,’ there must be more of an effort to connect changes at the genetic level (our genotype) to changes at the physical level (our phenotype).   Interestingly, questions of the relationship between genotype and phenotype form the cornerstone of 23andMe’s research arm, <a id="t3pm" title="23andWe" href="https://www.23andme.com/research/" target="_blank" rel="noopener noreferrer">23andWe</a>.
Finally, the authors argue that it will take scientists from a variety of disciplines — developmental biology, genetics, anthropology, anatomy, sociology, and many others — to fully examine the myriad of ways in which humans are set apart from our closest relatives.   It is at this point, the authors conclude, that we will fully understand what it means to be ‘human.’

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