AP Biology class blog for discussing current research in Biology

Tag: Genes (Page 1 of 2)

Serious Monkey Business Going on with these Tanzanian Monkeys

A team from the University of Oregon comprised of Maria Jose Ruiz-Lopez, a postdoctoral researcher, and Nelson Ting, a corresponding author and professor of anthropology, have discovered why a specific species of endangered monkeys in Tanzania are living in various different geographical areas that are increasingly becoming isolated from one another. It has been concluded that this situation is due to the monkey’s closeness to villages and the intentional forest fires by humans in an effort to create space for crops. Lopez collected 170 fecal samples of the Udzungwa red colobus monkey, a specific monkey used as indicator species in ecological change, for DNA analysis over five distinct forests in the Eastern Afromontane Hotspot. To approach this experiment, the team used landscape-genetics, a method that merges landscape ecology and population genetics. Though odd to use in tropical settings, this technique allowed them to investigate the dissimilarities between 121 monkeys and how human activity influences ecological changes. The largest difference between monkeys were of those who were separated by villages and/or zones that had a history of the highest density fires. The researches studied multiple variables at once and the monkey’s proximity to villages and man-made fires was still the most significant. Because these fires are stopping the monkeys from migrating, smaller groups of them are becoming more isolated, resulting in a decrease of genetic diversity and yielding to extinction variables.

This experiment regarding behavioral ecology, a way in which organisms react to abiotic factors in their environment, made me contemplate the human’s role in the environment and how we are strongly affecting the possible extinction or conservation of animals. This particular ecosystem is rich in diversity and it would be a tragedy for it to fall to extinction! There is no direct solution to this problem; after all, to have the power to alter a human’s ecological footprint and their decision whether to burn a forest or not is quite hard to seize control of. Do you believe with enough awareness and education, local communities would be able to create a local solution to save the diverse genes of these monkeys?

Original article can be found here.

Bullying and its Epigenetic Effect

Unfortunately, bullying is commonplace in most schools in America.  Most people are aware of the mental and psychological harm that bullying can cause, but not until very recently have they been aware of the lasting physical changes it can cause.  With the discovery of epigenetics, or the study of genetic traits or expressions that are not caused by DNA, but rather by the methylation or concealing of genes, a new door into the effects of bullying was opened. A group of researches from the UK and Canada performed a study on identical twins.  At age 5, the twins had not been exposed to bullies and expressed almost all of the same traits, physically and emotionally.  The researchers then waited until the twins were 12, imageand revisited only the twins that had different experiences with bullying (one twin was bullied when the other was not).  The researches found big disparities in the twins epigenome, or the way they express their genes.


The bullied twin’s protein that codes for a protein that helps move the neurotransmitter serotonin into neurons called SERT had significantly more DNA methylation in its promoter region.  This change is thought to dial down the amount of proteins that can be made from the SERT gene — meaning the more it’s methylated, the more it’s “turned off.”  Therefore, the bullied twin is unable to produce as much serotonin.  This effect is thought to persist through a person’s life.  The effects of bullying will persist an entire lifetime.


The researchers also tested how the twins responded to stressful situations differently.  The bullied twin had a much lower cortisol response than the twin that had not experienced bullying.  Cortisol is a hormone that helps people through stressful situations, like being bullied.  However, having too much cortisol is harmful to the body.  The bullied twin’s body turned off the gene that aids in cortisol production because they were being put in stressful situations so often by bullies that their body couldn’t tolerate the amount of cortisol they were producing.


This study is not only interesting from a scientific standpoint, but it is also very important in the movement against bullying.  These scientists proved that bullying not only does immense psychological harm, but it also effects people’s well being in a very real and lasting way.




Link to article:



Epigenetics and Brain Development

Pre-natal human brain development helps determine many major qualities a person may have in life. Research at the University of Exeter found that a type of Epigenetics, DNA methylation, helps us understand the differences between male and female brains. They studied that this type of gene regulation in pre-natal brain development may help us grasp more information about “sex differences in behavior, brain function, and disease.”

In the womb, as organs are developing, the brain has extreme plasticity. Professor Jonathan Mill of the University of Exeter explains how it is extremely vulnerable to changes because the brain is creating the structures that “control neurobiological function across life.” The research consisted of measuring genomic patterns of DNA methylation in the womb between 23 and 184 days after conception. DNA methylation is a chemical modification to one of the 4 nitrogen bases that helps create one’s unique genetic code. By studying the DNA methylation, or turning on of selected genes, in the pre-natal period when the brain is being developed, it helps scientists understand the susceptibility of different neurological diseases based on one’s sex. Helen Spiers from King’s College London explains how male and females have unique differences with certain disorders, such as Autism. She says how “autism affects five males to every female.”

The molecular switches that regulate genes were found to be gender specific. They also help differentiate brain cells from other cells in the body. This research gained traction in understanding the unique qualities of the DNA “blueprint” of males and females in their developing stages. The genetic switches that are turned on in pre-natal development for each gender are unique, and a deep topic of study. By doing so, in the future, scientists can research deeper into neurological diseases that are unique to males or females, and how they may be created in the womb.


Original Article:

Link to picture:

Links Between Human and Mice Obesity

A new study of the genomes and epigenomes of mice and humans is beginning to link the two, especially in regards to obesity.

As Andrew Feinberg, MD states, “It’s well known that most common diseases like diabetes result from a combination of genetic and environmental risk factors. What we haven’t been able to do is figure out how, exactly, the two are connected,”. Therefore, Feinberg began to study epigenetic tags to further understand gene usage.

His project with his team was to study the epigenetics of identical mice that were fed either normal or high-calorie diets. He found that the difference between normal and obese mice was the presence of chemical tags, or methyl groups, that prevent the production of proteins. This is significant because as we have learned, these types of modifications of DNA can be copied and inherited, which is then passed on into the next generation. This revealed that the normal and obese mice did not have the same location sites of their tags, giving them that alteration in their DNA. This is often seen in the alterations of the Agouti gene in mice.

Pictured here is effect of epigenetics on the physical appearances of mice (Agouti gene)

This proves that epigenetic changes are related to the environment and food sources that are around us, creating patterns based on one’s diet (which can create risk if a high-calorie intake is continuous).They also found that epigenetic changes affect genes that are already both linked to diabetes as well as those who aren’t, allowing them to further conclude that genes plays more of a role in diabetes than we previously thought.

This allows hope for future to provide epigenetic tests, which can prevent diabetes in those who are on track to have it later in life.

Article  Source:


Does long-term endurance training impact muscle epigenetics?



Epigenetics translates to “above” or “on top of” genetics. To be more specific, Epigenetics is the study of how modification of gene expression can cause changes in many organisms.

A new study from Karolinska Institutet in Sweden explores the theory that long-term endurance training alters the epigenetic pattern in the human skeletal muscle. The team that conducted the research also explored strong links between these altered epigenetic patterns and the activity in genes controlling improved metabolism and inflammation.

The study was conducted using 23 young and healthy men and women. The men and woman would perform one-legged cycling – where the untrained leg would be the control of the experiment. Four times a week and over the course of three months, the volunteers would participate in a 45 minute training session. Though skeletal muscle biopsies, supervisors would measure their markers for skeletal muscle metabolism, methylation status of 480,000 sites in the genome, and activity of over 20,000 genes.

At the end of the study, the researchers concluded that there was a strong relationship between epigenetic methylation and the change in activity of 4000 genes in total. Epigenetic methylation is defined as the “addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. ” Moreover, it was determined that methylation levels increased when involved in skeletal muscle adaptation and the metabolism of carbohydrates. However, methylation levels decreased in regions associated to inflammation.

Furthermore, Carl Johan Sundberg found that “endurance training in a coordinated fashion affects thousands of DNA methylation sites and genes associated to improvement in muscle function and health.” He believes that this determination could be vital to understanding the treatment of diabetes and cardiovascular disease as well as how to properly maintain good muscle function throughout life.

This article relates very much to our work in class as we learn the Molecular Genetics Unit. It connects because we are learning what happens when mutations occur in one’s genome and the impacts those mutations have on someone. For example, cancer is one of the most researched and explored topics in regard to how modification of gene expression alters organisms. Oncogenes and Tumor suppressor genes have vital impacts on cellular division, changes to cellular function, and the growth of tumors.

Fat lies: Did you inherit your body?

While obesity is typically attributed to over eating and a lack of exercise, researchers at Kings College London have identified a type of gut bacteria, called Christensenellacae, which influences a person’s genetic makeup and body weight. The study focused on fecal samples from 416 pairs of twins. Of these participants, identical twins had a larger abundance of the gene microbe than fraternal twins suggesting that the bacteria is highly heritable. Furthermore, researchers found that Christensenallacae is most common in the intestines of lean people and in experiments with mice they determined that this microbe alone promoted thinner mice. Thus far, research results suggest that a person’s genes influence his body weight by determining the types of bacteria that live in his intestines and that altering the Christensenallacae population could have a direct impact on his susceptibility to obesity. This research gives a very important window into the study of obesity prevention and gut microbes. Although the information is groundbreaking, further studies need to be conducted to determine if altering levels of this gut microbe is actually effective.

As researchers continue to expand their study, how do you think this discovery will be used in the future to combat obesity?

weight loss by pixabay

weight loss by pixabay

The Ability to Control Genes with Your Thoughts

A research group led by Martin Fussenegger, a professor of Biotechnology and Bioengineering at the Swiss Federal Institute of Technology, has developed a method by which brainwaves control the creation of proteins from genes. The technology wirelessly transfers brainwaves to a network of genes that allows the human’s thoughts to control the protein synthesis of the genes. The system uses a uses an electroencephalogram (EEG) headset, which records and transmits a human’s brainwaves and sets it to the implant in the gene culture.

A successful experiment of the system included humans controlling gene implants in mice. When activated by brainwaves, the gene implant culture would light up by an installed LED light. The researches used the human protein SEAP as the protein that would be generated in the culture and diffused into the blood stream of the mice. The humans were categorized by their states of mind: “bio-feedback, meditation and concentration”. The concentrating group caused an average release of SEAP. The meditation group released high concentrations of the protein. Finally, the bio-feedback group produced varying degrees of SEAP, as they were able to visually control the production of the protein as they could view the LED light turning on and off during the production process. The LED light emits infrared light, which is neither harmful to human nor mice cells. The system proved successful in its ability to translate brainwaves into gene control and protein production and its potential for harmless integration into the living tissue of humans.

The research group hopes that in the future a thought-controlled implant could help prevent neurological diseases by recognizing certain brainwaves at an early stage of the disease and translating the brainwaves into the production of proteins and other molecules that would work to counteract the disease.

Lights of ideas

To Know or Not to Know: Cancer Risk Gene Testing

Breast Cancer Cells

Genetic mutation testing has been a hotly debated and controversial topic since its initial prevalence in 1990.  Originally genetic testing was used to test females who have cancer in their family history for the BRCA 1 and 2 gene mutations.  Early detection of these mutations allowed for precautionary measure sure to be exercised prior to cancer even being diagnosed. The hereditary breast cancer risk testing was done mainly by Myraid Genetics but just last year the Supreme Court invalidated Myraid’s patents on the testing of the BRCA genes.  This ruling opened up many windows for the competition of Myraid in the field of genetic testing.  Many other companies and Myraid itself began not only offering BRCA testing but also more elaborate multi gene testing for the same price (apron $4000) as it would have been to test just the two BRCA genes.  This “bargain” influenced many patients to have more genes (up to 25) tested for mutations despite the fact that they may not have a family history to tendency towards certain cancers.  This multiplex testing has raised many eyebrows in the medical field because patients and doctors are getting information that sometimes they are unsure as to what they should do.  Doctor Kenneth Offit of Memorial Sloan Kettering Cancer Center stated when referring to multiple gene mutation testing, “because they could be tested,not necessarily because they should be…individuals are getting results we’re not fully educated to council them on. ” However Memorial Sloan Kettering Cancer Center is working on setting up a database for more knowledge on genetic testing.  This online forum, the Prospective Registry of Multiplex Testing (PROMPT) will allow for more research to be done and for patients to learn more.   Often genetic mutations are found and doctors are unsure how to react to the information due to lack of knowledge in that specific field of mutation leading to a specific type of cancer with out any family history.   Professor Mary-Claire King of the University of Washington voiced her opinion that, “We need to report back only what is devastating and clearly devastating.”  Meaning she felt that patients and physicians should only receive specific information as opposed to a full list of all the genetic mutations that tested position or inconclusive.  When do we know when to much information become frivolous? When it come to human health, the more we know the better the outcomes.  How will doctors be able to sift through extraneous data to find what truly are indications for higher risk of cancer?  Is this “extra” testing and information skewing the data and prognosis of many patients?


Main Article Used:


Where Does Language Come From?

Somewhere in Britain, there is a family where each member has varied speech difficulties. Some members can’t say words like “hippopotamus”, others have trouble reciting words that begin with the same letter. This family, known as the KE family, was subject to research by Oxford University in the early 2000’s to find that they had a rare gene mutation. The subtle mutation took place in the FOXP2 gene, where only one nucleotide was misplaced. However, this research has opened up the world to the search for the so called “language gene” in our bodies.


There are approximately 6,900 languages in existence today.

For a while, scientists thought that the FOXP2 gene was the “language gene” in our bodies. But further tests show that the gene has much broader capabilities in humans and other animals, such as mice. This evidence suggests that there is no one language gene but instead it relies on a much broader neural support system. With the existence of a language gene being much less concrete, understanding where language originates from becomes much more difficult. A 2010 study by neuroscientist Aldo Faisal showed that what led humans from making stone flakes to axes was a shift in cognitive capacity, not an improvement in physical coordination. Researchers believe that as toolmaking became more common in the world, humans may have acquired the mental capacity for language. Liverpool archaeologist Natalie Uomini says: “A lot of people would say that toolmaking came [before language], I would just say that they co-evolved.” 

Liverpool archeologist Simon Kirby takes a different perspective on the origin of language, arguing that the human brain alone is not enough to explain language and that we must look at the evolution of human culture as well. Through several experiments with fictional languages, Kirby has found that as a language passes from one person to the next, it develops a unique structure and evolves in such a way that participants could guess words that they weren’t even trained to know. This shows that there is a lot more than just brain function in the evolution language. There is a huge social component, and this makes the discovery of language’s origin even messier than originally thought.

The fact that such an integral part of our society is still relatively unknown biologically is fascinating, and many breakthroughs in this topic have been made within the last 5 years. What’s fascinating about the search for language is that it shows that as modern science progresses, we may not find the answer to the question that we asked, but instead find a whole new set of questions that we would never have thought to ask. What do you think about the origin language? Did it come to fruition before or after toolmaking? Leave your thoughts in the comments section below, thanks for reading!




Queen Bee and her special gene

A recent article, “Single gene separates queen from workers“, discusses a study published in Biology Letters carried out by scientists from Michigan State University and Wayne State University. They found a gene, which affects not only leg and wing development in bees but also the evolution of a bee’s ability to carry pollen. This gene, known as Ultrabithorax (UBX), gives worker bees the physical feature of their hind legs, which they need to carry pollen. 

Photo taken by: Christopher Down,_Montreux.jpg

Thanks to Ubx, workers develop a smooth spot on their hind legs that is home to their pollen baskets. Elsewhere on their legs, the gene causes the formation of 11 bristles, known as the “pollen comb” and it synthesizes a pollen press, a “protrusion” that packs and transports pollen back to the hive. Queens don’t have these features that the Ubx gene is responsible for. The scientists isolated Ubx and silenced it. The results were the disappearance of the pollen baskets, the growth of pollen combs, and reduction in the size of pollen presses. The scientists also concluded that pollen baskets play a smaller role in bees that are “less socially complex”, and the main scientist, Huang states that:  “We conclude that the evolution of pollen baskets is a major innovation among social insects and is tied directly to more-complex social behaviors.” 

So why is this information important? Well, given the recent downhill trend of bee populations, this research can contribute towards future attempts to make bees better pollinators. Do you think scientists should pursue this?



Microglia! Here to the Brain Rescue?

MicrogliaRecently, Massachusetts General Hospital (MGH) investigators have used a new sequencing method to identify a group of genes used by the brain’s immune cells, called microglia, to sense pathogenic organisms (bacteria that cause bacterial infection), toxins or damaged cells. Identifying these genes could lead to better understanding of the role of microglia both in normal brains and in neurodegenerative (nervous system) disorders. This discovery could also lead to ways to protect against brain dysfunctions caused by conditions like Alzheimer’s and Parkinson’s diseases.

The set of genes microglial have also been able to react with their environment. “We’ve been able to define, for the first time, a set of genes microglia use to sense their environment, which we are calling the microglial sensome,” says Joseph El Khoury, MD, of the “MGH Center for Immunology and Inflammatory Diseases and Division of Infectious Diseases, senior author of the study”. A type of macrophage microglia are known to consistently test their environment in order to sense any indication of infection, inflammation, and injured or dying cells. Depending on the situation they are involved in, the microglia reacts in a neurotoxic response, replying in a defensive protective manner. The microglia can “engulf pathogenic organisms, toxins or damaged cells or release toxic substances that directly destroy microbes or infected brain cells”. In this way microglia is extremely beneficial to the brain because it is able to identify infections before they have any direct contact with the brain. However, this neurotoxic response can also damage healthy cells and can “contribute to the damage caused by several neurodegenerative disorders”, so keeping the response under control is crucial.

El Khoury’s team’s “next step is to see what happens under pathologic conditions” and to define the sensome of microglia and other brain cells in humans, identifying how the sensome changes in central nervous system disorders, and eventually finding ways to safely manipulate the sensome. Discovering the microglia gene is a large and successful step to eventually finding a cure for infectious brain diseases, such as Alzheimer’s and Parkinson ’s disease.

Cuts, Scrapes, and Hair Loss a Thing of the Past!


Can adults repair their tissues as easily as children can? A study currently conducted at Boston Children’s hospital is attempting to find the answer to this question. Researchers have found that by activating a gene called Lin28a, they were able to “regrow hair and repair cartilage, bone, skin and other soft tissues in a mouse model.”  The scientists found that Lin28a works by enhancing metabolism in mitochondria—which, as we learned in class, are the “powerhouses” of the cells. This in turn helps generate the energy needed to stimulate and grow new tissues.
This discovery is a very exciting one for the field of medicine. The study’s senior investigator George Daley said, “[Previous] efforts to improve wound healing and tissue repair have mostly failed, but altering metabolism provides a new strategy which we hope will prove successful.” Scientists were even able to bypass Lin28a and directly activate the mitochondrial metabolism with a small compound and still enhance healing. Researcher Shyh-Chang says of this, “Since Lin28 itself is difficult to introduce into cells, the fact that we were able to activate mitochondrial metabolism pharmacologically gives us hope.” Since it is difficult for scientist to actually introduce Lin28a into a cell, it might be easier to simply synthetically create a substitute and introduce that. Either way, I think this is a very promising discovery! What other uses can you think of for this discovery?



Dr. Light

Cardiac arrhythmia is a problem with the rate of heart beat that currently affects 4 million Americans. During arrhythmia, the heart may beat too fast, too slow, or have an obvious irregular rhythm. In some cases, this heart condition may be life-threatening with the ability to damage the brain, heart, and other organs due to the lack of blood flow.

Oscar Abilez, a cardiovascular physician at Stanford University has developed the solution to this condition: light. With his team, he is working to create a new biological pacemaker that is able to control the heart with light. The first phase of his research involves optogenetics. This uses techniques from both optics and genetics to control the activity of individual neurons in living tissue. In 2002, German scientists were able to isolate the genes for the proteins called opsins. Before this discovery, algae and few other organisms were the only know carriers of light sensitive cells. These opsins, however, are responsible for cells’ light sensitivity in humans and modify the genetic code of other cells so that they, too, would produce these opsins. 

The next phase of his research involves stem cells. Oscar Abilez hopes to convert the stem cells light-sensitive cardiomyocytes from a person who is suffering from this condition.  These cells that make up the muscle tissue in the heart  would be able to be “grafted” onto a person’s heart. This would then ideally carry out Abilez’s vision, which he hopes will be achieved in the next decade or so, allowing physicians to control the whole heart’s rhythm using light.VPC_1


Possible HIV Remedy?

There wide array of deadly diseases that affect millions of people worldwide. Do you ever wonder if there could be a cure for just one? A team of researchers led by Dr. Caroline Goujon and Professor Mike Malim at the Department of Infectious Diseases in King’s College London has recognized a new gene that may have the ability to prevent HIV (Human immunodeficiency virus), a virus that slowly replicates and eventually causes AIDS. AIDS is a human condition that causes continuous failure of the immune system that could potentially lead to life-threatening infections and cancers. The research team has concluded that the human MX2 gene could play a major role in the path to finding an official cure for the deadly virus.

The MX2 gene is the Interferon-induced GTP-binding protein MX2. The protein encoded in this gene has nuclear and cytoplasmic forms. Researches have concluded that this protein could “lead to the development of new, less toxic treatments where the body’s own natural defense system is mobilized against the virus.” The scientists began the experiment by presenting the virus to human cells where the HIV virus had an encounter with two different cell lines and observing effects. After an intense study of the experiment, they detected in one cell line the MX2 gene was “switched on” and in the other cell line the gene was “silenced”. In the cell where the MX2 was switched off the virus duplicated, but in the cells were the gene was switched on no new viruses were produced or continued. In this way, the gene tested positive for its ability to fight off the virus.

The recent finding by the researchers brings way for other researches and scientist to continue to advance their knowledge about the virus. The goal would be to allow the 34 million people worldwide who are infected with HIV to lead a life free of the


The damages of Sleep Loss

Roughly 30 million Americans are “just trying to catch up on their sleep.” 20% of Americans report that they get less than 6 hours of sleep on average. This nation-wide sleep loss is “taking a toll on our physical and emotional health, and on our nation’s highways.” Sleep loss leads to a variety of inconvenient issues.

image taken from WikimediaCommons

According to Discovery Health, Inability to handle stress, inability to concentrate, poor memory, poor decision making,  increased appetite, diminished motor skills, relationship trouble, medical problems, and mood swings can all be the ill effects of sleep deprivation. This has been known by scientists for a long time, but the reasons on a molecular-level were unclear.

However, recent headway has been made in understanding the consequences of sleep deprivation on a molecular level. A new study at the University of Surrey in England showed changes in gene activity in 26 people who had built up a sleep deficit. Reports in the Proceedings of the National Academy of Sciences showed that after a week of considerable sleep deprivation the blood tests of the 26 subjects showed changes in 711 of their genes.

The “changes” observed in the genes including a disruption of the cell cycle; the cells stopped their circadian rhythm. On the other hand, cells that don’t typically follow a cycle fell into a daily rhythm. Many of the genes that showed changes were related to the immune system. This would account for the previously and widely observed medical issues connected with sleep loss. “The researchers conclude that skimping on sleep can drastically change the body’s daily rhythms and may lead to health problems”.



Main article:

additional articles:

picture link:

Genetically Modified Food? Now You Can Know For Sure.

Whole Foods Market has officially become the first grocery store to require the labeling of all genetically modified foods. In an article published by The New York Times, on Friday, March 8th, Whole Foods Market announced that they will be labeling all genetically enhanced food products.

According to Whole Foods president A. C. Gallo, the new labeling requirement was implemente due to consumer demand. Mr. Gallo stated that that their “manufacturers say they’ve seen a 15 percent increase in sales of products they have labeled.”

Today, genetically modified foods are of great abundance in the global food supply. For example, most of the corn and soybeans grown here in the United States are genetically altered. The alterations make the soybeans resistant to a herbicide used in weed control, and causes the corn to produce its own insecticide. Scientists are currently working on producing a genetically modified apple that will spoil less quickly, and genetically modified salmon that will grow faster.

What do you guys think of the position Whole Foods is taking with labeling their products? What are your thoughts on genetically modified food in general? Do you believe that genetically modified foods are safe for humans to consume? Please leave your thoughts and comments below.


Genome Project Helps Connect Ethnicity to Diseases

Though people from all over the globe share over 99% of the same DNA, there are subtle differences that make us all individuals

Scientists at the Washington University School of Medicine in St. Louis have started the “1,000 Genomes Project” in which they will decode the genomes of 1,000 people from all over the world in hopes of finding genetic roots of both rare and common diseases worldwide. On October 31st, the results of DNA variations on people from 14 different ethnic groups were published, but the scientists hope for the project to expand to involve 2,500 people from 26 different world populations. According to Doctor Elaine Mardis, co-director of the Genome Institution at Washington University, “[scientists] estimate that each person carries up to several hundred rare DNA variants that could potentially contribute to disease. Now, scientists can investigate how detrimental particular rare variants are in different ethnic groups.”


We are One

Everyone on earth share 99% of the same DNA. That means you, your best friend, your mortal enemy, your boyfriend/girlfriend, next door neighbor, and The President of the United States all share 99% of your DNA. However, there are rare variants that occur with a frequency of less than 1% in a population that are thought to contribute to both rare diseases and common conditions (i.e cancer, diabetes). The rare variants explain why some medications do not effect certain people or cause nasty side effects (i.e insomnia, vomiting, and even death).


The goal of the “1,000 Genomes Project” is to identify rare variants across different populations. In the pilot phase of the program, researchers found that most rare variants different from one population to another, and the current study supports this theory.


The Study

Researches tested genomes from populations from the Han Chinese in Beijing (and the Southern Han Chinese in China) to Utah Residents with ancestry from Europe to the Toscani people of Italy to the Colombians in Columbia. Participants submitted an anonymous DNA sample and agreed to have their genetic material on an online database. Researchers than sequenced the entire genome of each individual in the study five times. However, decoding the entire genome only detects common DNA changes. In order to find the rare variants, researchers sequences small portions of the genomes about 80 times to look for single letter changes in the DNA called Single Nucleotide Polymorphisms, or SNPs.


The Results and Importance

The Study concluded that rare variants vary from one population to another. Researchers found a total of 38 million SNPs, including 99% of the rare variants in the participants’ DNA. In addition, researchers found 1.4 million small sections of insertions or deletions and 14,000 large sections of DNA deletion. The “1,000 Genomes Project” is incredibly important in medical science. It now allows researchers to study diseases, such as cancer, in specific ethnic groups. I personally think this project in incredibly important. As an Ashkenazi Jew from Eastern Europe, my family has a medical history of certain cancers and diseases. With the results of the “1,000 Genome Project,” researches could potentially find out why, and maybe even find a cure for some of these diseases.

Blondes Unite!

Despite the ‘dumb blonde’ jokes, and Danish or Dutch teases, I have enjoyed being blonde haired. As far as hair colors go, I think being blonde is perfectly suitable. However, there are certain preconceptions about hair color and race that people have. One being that people of certain ethnicities and races cannot have naturally blonde hair. This new study proves that idea wrong.

Photo Cred: Aust Defence Force

An article in the New York Times describes the experiments done on a group of people from the Solomon Islands. For some inexplicable (but not any more!) reason, many of the dark- skinned inhabitants have naturally blonde hair. But why?

Scientists did experiments on a giant chunk of the islanders, taking saliva samples from over a thousand people. Then they looked specifically at 43 blonde, and 42 dark haired islanders. What the discovered was that the blonde haired islanders had a specific gene, now called TYRP1, that changes the pigmentation of their hair.

What is perhaps most surprising is that Europeans have no trace of the gene in their genome. This, as Carlos Bustamante says: “For me it breaks down any kind of simple notions you might have about race,”

Hopefully these scientists will continue to learn more about hair and skin pigments and the genes that cause them. Do you like your hair color? Ever wonder why certain people seem to have one type of hair color instead of another? Just remember, it can all be explained by the genes.

Sweet Genes Not So Sweet

Do you enjoy eating foods that taste sweet? Do you also like to eat meat? Well, what would you do if you ate so much meat that your genes responsible for detecting the sweet taste suddenly stopped? Would you be upset? I certainly would be. Thankfully, humans do not have to worry about this problem yet, but a recent study shows that animals that are specialized carnivores have lost the power to taste sweetness.

Credit: Martin Heigan

The study analyzed twelve different mammals and their sweet detector gene Tas1r2. The researchers found that in seven out of the twelve animals, Tas1r2 experienced mutations. The gene carried disabling glitches in hyenas, otters, fossa, banded linsang, sea lions and two different kinds of seals. What these animals have in common is that they are all predators. The study’s coauthor Gary Beauchamp believes that this means that the mutations in Tas1r2 “could easily spread through populations.”

While these carnivores have lost their ability to taste sweetness, this loss is not universal among meat eaters. For example, animals like red wolves are fervent meat eaters, but have not lost their genetic sweet spot. Beauchamp believes that the carnivores that have not lost the function of this gene will soon lose it in the future due to evolution.

However, there are many arguments in opposition to Beauchamp’s proposal. Animals that do not specialize in meat may have also lost their ability to taste sweetness. Chickens eat both plant and animal foods, but do not seem to notice sweetness in their food and appear to lack a functional Tas1r2. Huabin Zhao of Wuhuan University in China believes that chickens are just one reason that Beauchamp’s conclusion is not convincing. Zhao suggests that “narrow diet specialization might be a better explanation” for the meat-eater sweet-loss scenario.

The only way to determine if Beauchamp’s conclusion is valid is

to see if there will be disabling genetic glitches in Tas1r2 in other types of carnivores in the future. If this does occur, then this genetic mutation has the potential to shape the evolution of carnivores. Similar to these carnivores, people have also had their “use-it-or-lose-it” sensory evolution. For example, humans are not great at detecting odors and even worse when it comes to noticing pheromones, the strong animal-to-animal chemical communications. Only time will tell if the mutations of Tas1r2 will spread to all carnivores, but let’s hope humans do not lose the functionality of their sweet detector gene because sweet food tastes too good!

Identical but Not the Same


Some Rights Reserved. More Information:

After studying genetically inherited traits and diseases it could be easy to assume that genes determine everything about us. While it is true that colorblindness is a sex-linked trait – there is certainly more to the story.

Monozygotic “identical” twins are genetically identical, so they should be the same in all ways shouldn’t they?

Why, then, does one twin get early onset Alzheimer’s disease and the other “identical” twin doesn’t? The same is true for height, autism, and cancer. Although, when one twin has a disorder the other is more likely to get the disease also, that is not always the case.

In the January edition of National Geographic, author Peter Miller discusses the newest theories about how genes, environoment and epigenetics affect our life (and the end of it).

Twins offer scientists a unique opportunity to study how genetically identical people differ. Basically, that means scientists can study how things other than genes affect human development and lifespan. Already, scientists have found that a persons height is only 80% determined by genetics because the heights of “identical” twins differ by about .o8 on average. Using IQ tests, scientists have nearly disproved John Locke’s Tabula Rasa or blank slate theory (the idea that children are born with a blank mind that is either stimulated – (and made intelligent) – or not –  (kept unintelligent)). Specifically, scientists studied twins who had been separated at birth and adopted into different families. In this way, scientists have found that intelligence  is about 75% controlled by genetics.

So that leads to the question, what is it besides genes that affects us humans so drastically?

Environment has something to do with our differences. However, that cannot be the whole story. “The Jim Twins” as they are called in the twin science community, were studied in the 1870’s. They were adopted into different families where both boys were named Jim. Then went on to have the same jobs, marry wives of the same name (two Lynda’s first then two Betty’s), enjoy the same hobbies, enjoy the same brand of cigarette and beer, name their sons James Allan and James Alan… the list goes on. These two lived very similar lives, yet they grew up in very different environments. If environment isn’t the only factor in creating difference then what is?

Scientists have recently come to believe that epigenetics plays a significant role in our lives. Epigenetics (site 2) can be seen as the meshing of environment and DNA. In the words of author Peter Miller “If you think of our DNA as an immense piano keyboard and our genes as keys – each key seach key symbolizing a segment of DNA respinsible  for a particulare note or trait, and all the keys combining to make us who we are – then epigenetic prcesses determine when an how each key can be struck changing the tune.”  Environmental changes do have some impact.  When a pregnant mouse is put under stress during the pregnancy it can create changes in the fetus that lead to abnormal behavior as the rodent grows into adulthood.

However, scarily enough, many epigenetic changes appear to occur randomly (thus creating a probelm for the organized nature/nurture theory). Currently work is being done studying DNA methylation, which is known to make the expression of genes weaker or stronger. Specifically, Andrew Feinburg, director of the Center for Epigenetics at Johns Hopkins School of Medicine, is working to find how DNA methylation relates to autism. Currently, he is using scanners and computers to search samples of DNA from autistic twins who have the disease in varying degrees. He is looking to compare how and why

the genes are expressed differently.

In the end, all we know is that there is more to our future than our genes can tell us. Yes, our genes play a huge role in who we are as people – in terms of appearance, character, intelligence and more – but there are some variables that our environment and epigenetics control.

Main Article: Miller, Peter. “A Thing or Two About Twins.” National Geographic. Jan 2012: 38-65. Print.

Page 1 of 2

Powered by WordPress & Theme by Anders Norén