Genetic Insights into Why Depression Affects Women More Than Men

       In a recent study done by Dr. Jodi Thomas at the School of Biomedical Sciences at The University of Queensland, it has been found that major depressive disorder (MDD) impacts almost twice as many women as it does men. Researchers findings in the study with over 200,000 men and women with MDD start to unpack the underlying causes of MDD in both sexes. They categorized genetic effects into three separate groups: shared effects present in both sexes, sex-dependent effects that differ in magnitude or direction, and sex-specific effects present in only one sex. Their analysis revealed that women carry about 13,200 genetic variants linked to MDD while men have only 7,100, suggesting that women might bear a higher genetic burden (including 6,100 variants potentially unique to females). Additionally, three genomic regions were identified as major only in women, supporting the presence of sex-specific genetic influences.

The study also focused on genetic correlations between MDD and metabolic traits like body mass index (BMI) and metabolic syndrome. These correlations were stronger in women, consistent with clinical observations that women with MDD more often experience metabolic symptoms. With this, researchers recorded limitations in statistical power, meaning that not all causal genetic regions could be definitively identified. In addition, genetic correlations between men and women with MDD were slightly lower than expected, underscoring possible differences in cohort characteristics. This suggests that twin studies and GWASs may capture distinct aspects of genetic risk.

    Ultimately, the study highlighted a noteworthy variant on the X chromosome in men, mapping to the IL1RAPL1 gene, which is involved in memory and has been associated with several other traits but not previously with MDD. While the role of this gene in male depression is still unclear, it provides a promising opportunity for further research. Overall, the study harps on the importance of sex-stratified analyses to comprehend the biological function of MDD and points to the need for more data collection and further investigation into molecular mechanisms that mediate sex-dependent and sex-specific genetic impacts.

Sources:

https://www.nature.com/articles/d41586-025-03374-0

https://www.nature.com/articles/s41467-025-63236-1

https://www.mayoclinic.org/diseases-conditions/depression/symptoms-causes/syc-20356007

Science Reveals Genes That Help Drive Dyslexia

 

Dyslexia is a learning disorder that involves difficulty reading due to problems decoding words and identifying speech sounds. Symptoms of dyslexia include; late talking, learning new words slowly, reading below the expected level for their grade, and more. There is no cure for dyslexia however parental support and tutoring at school can help the child to read better. Science has been studying what genes drive dyslexia. Researchers have begun to pinpoint specific genes responsible for the disorder. The findings show that common genetic differences have the same effect on both genders. Also, there is a linkage between dyslexia and ambidexterity. The results also showed that dyslexia is very closely genetically related to performance on reading and spelling tests. To determine these conclusions, the researchers tested millions of genes and genetic variants and found 42 significant variants. Many of the genetic variants that were linked to dyslexia were also linked to attention deficit hyperactivity disorder (ADHD). The study also found that several genetic variants were associated with the same symptoms of dyslexia in different languages, such as Chinese. This was the largest genetic study on dyslexia and is a great start at determining the specific genetic markers for the learning disorder. 

Genetic Variation could Predict Timing of Menopause

A recent study involving 200,000 women revealed hundreds of genetic variants that were involved in determining the age of menopause. 290 different variants dictate how the body responds to eggs with damaged DNA. Researchers believe that one day studying these variants will broaden reproductive lifespans, and improve in vitro fertilization. Studying these variants may also lead to the creation of a diagnostic test that helps predict when women will begin their menopause cycles. Not only do these variants allow scientists to predict reproductive processes, but it allows researchers to learn so much more about the genetic influence on reproductive processes. Studying these variants has already been so beneficial. First off, it has led to the discovery that many women who have delayed menopause have lost function of the CHEK2 gene. This gene, as a result, produces the CHEK2 protein causing cells with damaged DNA to stop dividing or worse, triggering to self-destruct. Without studying these variants, we would not have the abundance of knowledge that we do regarding the female reproductive system. Knowing these things allows women to take precautions ahead of time and allows them to lead a better and healthier life.




Article Link: https://www.nature.com/articles/d41586-021-02128-y

Related Link: https://www.theguardian.com/society/2021/aug/04/genetic-secret-to-age-women-start-menopause-discovered

Linking Dog Behavior and Genetics

 

    In a study done among 101 dog breeds, it was found that certain behaviors were related between genetically similar breeds. It is common knowledge that different breeds of dogs differ in their behavior, but the genetics behind this have been of interest in recent years. In performing this study, data came from databases as well as surveys from dog owners, asking dog owners about their purebred dog's behavior. They collected data from over 14,000 dogs, and gave each dog a score on fourteen different behaviors. Geneticists analyzed these behavior scores, looking for genetic similarities between dogs who had similar behavior scores. They discovered that for behaviors such as aggression, trainability, and chasing, genes contributed between 60% to 70% of behavioral variation among breeds. For example, border collies and poodles had higher trainability scores while chihuahuas had higher aggression scores. The strong correlation between certain behaviors and genetics shows that the specific behaviors that genetics play a role in have been selected over time by humans. Humans have bred for specific traits, which is increasing the correlation. 

    The scientists also looked into specific genetic variants that might also contribute to behavioral differences. 131 out of thousands of variants stood out, but after much research, it was decided that no single gene was very closely related to any behavior. This just means that differences in behavior between breeds is affected by multiple genes, all interacting with each other. Although genes do play a role in the predisposition of behavior in dogs, environment still plays a role in dog behavior. That being said, I think that environment may play a larger role in dog behavior than genes. If a dog is raised in an abusive home, most of the time, they will be more aggressive and hostile, solely because of the way they have been treated. On the contrary, if you raise a dog in a positive, healthy environment, they will most likely be friendlier. A trait that I think could be affected more by genes than environment however, would be trainability. It would be interesting to see more research done on that trait in different dog breeds. 

https://www.sciencenews.org/article/dog-breed-behavior-genetics

https://penntoday.upenn.edu/news/genes-play-role-dog-breed-differences-behavior

Southeast Asia Free Divers Evolved Larger Spleens

     

        The article Free Divers From Southeast Asia Evolved Bigger Spleens is about the Bajau people, also known as sea nomads, that have adapted larger spleens overtime which increases the number of oxygenated red blood cells when diving. The genetic variant increases their endurance when free diving in open ocean. This natural selection in humans is believed to have occurred over hundreds possibly thousands of years. The Bajau people spend the majority of their day in the ocean, diving for fish and shellfish. This has been their method of hunting for over a thousand years now. The body has a number of tricks that allows them to increase their time they can spend under water. One is the increase in red blood cell production which expands lung capacity and more efficiently delivers oxygen to the tissues and organs in the body. The adaptation that is rare and distinct to these groups of people is the increased size of the spleen. The larger spleen stores oxygenated red blood cells and contracts while diving to release the blood cells into the blood circulation throughout the body.

        A graduate student from the University of Copenhagen, Melissa Ilardo, sought out to understand whether the Bajau had their own technique to deal with hypoxia while diving. She used an ultrasound machine to measure the spleen of 43 Bajau and 33 Saluan participants (unrelated to Bajau population). She was interested in spleen size, because she knew the spleen could get quite large in diving marine mammals. Melissa Ilardo also took saliva samples for genomic sequencing. Even while taken into account age, gender, and weight, Melissa Ilardo and her team found that the spleens of the Bajau people were on average 50% larger than the Saluan. The team then compared the genomic sequences of the Bajau and Saluan people to genomic sequences to those of Han Chinese (control - unrelated group). While scanning the variants, they were able to identify 25 polymorphisms unique to the Bajau genomes. This shows the natural selection is definitely at play here. A phylogenetic tree was created which calculated that the Bajau and Saluan people diverged about 15,000 years prior. 

       One of the top variants of interest was one adjacent to the gene for PDE10A which is involved in regulating smooth muscle contraction, including the muscles that surround the spleen.  The teams top hit was a variant adjacent to the gene BDKRB2 which is the only gene that was previously associated with diving response of humans, but not spleen size. They do not yet know how it affects the diving reflux and more studies would need to be done in the future. I found this study and analyses to be extremely interesting. It gives evidence of natural selection among the human species and a timeframe for how long it takes for these adaptions to make way. I am excited to see where they take this study in the future and what more is to come from it. 

ADHD and Genetic Variants

About 2.5% of adults and 5% of children are affected by ADHD (attention deficit hyperactive disorder).  The disorder can cause a lack of attention, hyperactivity, disorganization, and much more, making it seem like a behavioral problem in many cases.  However, scientists have discovered specific genetic variants that have been shown to link to ADHD, which could change the way many people view the disorder.  These variants can account for an increase in the risk of ADHD.  Although scientists knew ADHD was heritable, it was always difficult to find these genetic variants.  A study scanned 55,000 individual's genomes, in order to do research on the topic and found that there were 12 regions in the genome where some changes could increase the risk of having ADHD.  These findings do not account for much of the "genetic risk," says Professor Anders Borglum, but represent the "tip of the iceberg" and can lead to many more discoveries in the future.  This could lead to finding out more about the biological elements of the disorder, and can help in finding new drugs to treat the condition.  This in turn could help those who are just seen with "behavioral problems" be more understood and not as stigmatized.
https://www.theguardian.com/society/2018/nov/26/scientists-find-genetic-variants-that-increase-risk-of-adhd
https://www.webmd.com/add-adhd/guide/attention-deficit-hyperactivity-disorder-adhd#1

Link Between Reproduction and Heart Disease

Researchers believe they may have found a reason for the persistence of coronary artery disease. After examining genetic variants associated with the disease, it was found that the illness spread rapidly in humans within the last 10,000 years. This lead to the belief that these genes must have recently began to provide an evolutionary advantage. The researchers then reviewed 143 studies and noticed a link between these genes and reproductive functions, like fertility and fetal development and survival. It is thought that the genes associated with coronary artery disease have lasted in the population due to those with it having more children. In the last thousands of years it was probable that having enhanced reproductive functionality was advantageous, as infectious disease increased mortality rates during this time. People with the genes for this heart disease most likely had more children, even if they were to develop the disease later in life. Our body has a way of compensating for enhanced survival whether we are aware of the enhancement or not. I believe it is best to let nature do as it intends, instead of tampering with possible advantages that would otherwise be lost through things like excessive gene therapy.

Article

The Influence of Genes on Puberty

A recent study identified 389 genetic signals related to the timing of puberty in men and women by performing a detailed assessment of genetic variants in 329,345 women. Moreover, the data was confirmed in a study of 39,543 women from a study performed in Iceland. The researchers identified 389 independent genetic signals in women and that these genes are also associated with voice breaking. The researchers also discovered rare variants of imprinted genes. It was stated that the rare variants in the imprinted genes lowers the age of puberty only if it is inherited from the father. 

The study also stated that when the timing of puberty is earlier, the risk of cancer also increases due to the increasing levels of sex hormones. If this study is continued and improved, we can gain better understanding of the relationship between genes and puberty, as well as the diseases associated with increasing sex hormones and early puberty. 

https://medicalxpress.com/news/2017-04-hundreds-genes-puberty.html
http://endocrinenews.endocrine.org/tri-point-genetics-epigenetics-puberty/

Tibetan Mastiffs Can Survive Extreme Conditions Thanks to the Wolves

Tibetan mastiffs are a very interesting breed; they can survive in "thin, frigid mountain air," whereas most people and animals cannot. Researchers believe that they may have inherited this tolerance from breeding with wolves over 20,000 years ago. The "ancient" wolves were already able to live at heights like the mastiffs do now. Researchers also noted that Tibetan people have a trait similar to this from breeding with "Denisovans," which are a group of extinct humans. Researchers find this study very interesting because they are able to compare it to the changes in humans as well.

The study adds to growing evidence that such ancient mating events have sometimes played a vital role in the adaptation of modern species to their environments, the scientists say.

“It’s a very cool discovery … which turns out to be a mirror of what’s going on with the humans [there],” says Elaine Ostrander, a geneticist at the National Institutes of Health in Bethesda, Maryland, who was not involved with the study.

Researchers think that a dog breed from China traveled to the Tibetan Plateau about 24,000 ago. They adapted over this time to the icy climate, and formed into the hairy, large dogs we see today. In order to survive these temperatures, the dogs, along with the Tibetan people, produce less hemoglobin. Hemoglobin is the protein that carries oxygen in red blood cells. A variation of the gene, EPAS1, is what aids this adaptation. This variant helps reduce the chance of a clot or stroke when red blood cells try to make up for lack of oxygen.

The study shows that the gray wolves may have been the source for this variant. To test this prediction, researchers tested DNA segments from 29 different gray wolves. They noticed that the mastiffs were closely related to Chinese dogs more than they were to the gray wolves. Two other genetic areas in mastiffs were uncovered in the gray wolves as well.

This is definitely a very interesting article. This study reveals how people and animals have adapted to live in more extreme clients. The fact that both humans and the mastiffs have similar variants of the gene is very extraordinary in the world of genetics.

http://www.medicinenet.com/hemoglobin/article.htm
http://www.sciencemag.org/news/2016/12/tibetan-dogs-can-survive-high-altitudes-thanks-ancient-breeding-wolves

How Animals Change Behavior Based on Social Information

At Rockefeller University's Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, Cori Bargmann and her coworkers created a variety of experiments in order to look and understand how animals use social information to adapt their behavior. This was done using Caenorhabditis elegans, a tiny roundworm with easily detectable habits. This is a simple organism that can give experimental data that may apply to all species and humans as well.

There are two types of ways that C. elegans looks for food: an exploratory behavior known as roaming and a less active behavior known as dwelling. The research group looked at the differences in the worms' behavior in different environments and settings. This led them to a new role for pheromones called ascarosides. A pheromone is a chemical that an animal produces which changes the behavior of another animal of the same species. The ascarosides are signaling molecules that control behavior in the roundworms such as male sexual activity. It was also observed that this pheromone helped the animals modify their behavior depending on how many worms were nearby. In crowded environments, the worms with a specific genetic variation adopt different behaviors than those who don't. Genetic variants were either insensitive or sensitive. Those that were insensitive make less of a key protein that senses the ascarosides than those that are sensitive.

According to Bargmann, one of the ways that behavior evolves is through the appearance of genetic changes that affect sensory capabilities. This study also shows that natural trait variations result because of environment and genetic changes. Through this study, it was recognized that population density can be a regulator of behavioral strategies. This can be used for future studies to see how human behavior's link to its animal origins. I think this study is awesome because it shows that animals are paying attention to their surroundings and the animals around them. Humans do the same thing and are constantly watching, observing and changing because of the people whom they are social with or who are around them constantly.

Genetic Variants in Psychiatric Illnesses

Bipolar disorder affects approximately 1-3% of Americans, causing intense mood swings that are very disruptive to the individual.  Recent studies show that variations in two different genes, CACNA1C and CACNB2, are significantly associated with psychiatric conditions such as bipolar disorder, schizophrenia, and major depression.  The CACNA1C gene is known to impact brain function involved in emotion, attention, thinking, and memory. 

Scientists can analyze which genes travel with or segregate with bipolar disorder by a mechanism called exome sequencing.  The trial involves examining the genomes of the individual with bipolar disorder as well as their family members.  In this particular study, researchers found 84 genetic variants that were previously linked to schizophrenia and autism.  Those genetic variants were also considered to be destructive to the gene that is responsible for coding.

It makes perfect sense that psychiatric conditions such as schizophrenia, bipolar disorder, autism, and major depression have similar genes in common.  All of those disorders have similarities in terms of affecting the way we think and feel.  I hope to see more progress in detecting genes responsible for certain psychiatric illnesses in the near future.  

Your DNA May Explain High-Calorie Food Cravings

This is a a very interesting article which places emphasis on obesity or consuming a high calorie diet and its relation to ones DNA. Genetic variants were identified which the brains response to high calorie foods. It was very intriguing the fact that the reason for the FTO variant had a higher rate of obesity was because of dopamine signals in the brain which triggered them to crave junk food, which leads to these people consuming a poor diet. The researchers did indicate that each individual may respond differently in terms of treatment regarding these genetic variants. So the idea here is that there has to be a drug created that inhibits these variants effective enough to help the vast majority of the population. My guess would be to genetically alter drugs to act as an antagonist and in a way reduce the craving of any given person. But, more importantly these drugs most certainly should be tested on other animals before trying to treat them on humans.

http://health.usnews.com/health-news/articles/2015/11/05/your-dna-may-explain-high-calorie-food-cravings

http://ghr.nlm.nih.gov/gene/FTO

Some People 'Hardwired' to Prefer High-Calorie Foods, Study Finds

A new genetic study from a team of researchers at Imperial College London in the United Kingdom has identified two genetic variants, which exist near the FTO and DRD2 genes, as potential influences on whether a person prefers high-calorie or low-calorie foods.  The FTO gene has been proven to be associated with obesity and the DRD2 gene plays a role in dopamine regulation in the brain, which affects our sense of reward and craving in our bodies. With obesity being such a huge problem in the United States, as more than a third of the adults in the U.S. being obese, Dr. Tony Goldstone and his colleagues set out to determine whether these genetic variants could be the reason why so many people find it hard to stick to a healthy diet.

The team performed DNA genotyping on 45 white European adults, with ages ranging from 19 to 55 and of body mass index's ranging from 19.1 to 53.1 kg/m^2, to determine the presence of variants near the FTO and DRD2 genes. The subjects were then asked to view pictures of high-calorie and low-calorie foods and rate how appealing they found the food, while researchers used functional magnetic resonance imaging to analyze their brain activity.

From the study, researchers found that participants who possessed a variant near the FTO gene and who rated the high-calorie food as the most appealing showed greater activity in the orbitofrontal cortex and striatum of the brain. These findings suggest that individuals with the FTO gene variant have a great risk of obesity as it influences dopamine signals to trigger a sense of reward and craving when in the presence of unhealthy, high-calorie, food. This causes the person with the gene to experience more cravings than the average person when in the presence of food that is high in fat and/or sugar.  

From the results of the experiment, the team of researchers believe those who have the FTO and DRD2 gene variants may need more personalized treatments for obesity, such as using gut hormones to target dopamine cells in the brain and alter the hormone's effect on the craving for high-calorie foods.  

I, personally, find this article fascinating. It's interesting to believe that something such as our desire to eat unhealthy foods can be influenced by our genes and genetic variants. It really speaks to how much our genes influence us, not only in appearance, but in behavior. The study definitely allows us to better understand the biology and genetics behind our behaviors, especially the ones that predispose some of us to crave and overeat high-calorie foods. I think it also goes a long way in helping to potentially solve the obesity problem in the U.S.

For a link to the original article click here
For more information on the FTO and DRD2 genes and their effect on obesity click here

Superior Breakthrough in Genetic Testing for Newborns in the NICU

In the Neonatal Intensive Care Unit, more than half of the newborns there are born prematurely.  The remaining portion of the infants have problems that doctors have not diagnosed yet.  Scientists at Children's Mercy Hospital in Kansas City have had a breakthrough in genetic screening technology that can screen a newborn's DNA in about 26 hours.  The scientists have stated that the new screening process resulted from advancements in sequencing technology and technique to understand the function of the genes.  Screening starts with the doctor logging into a database (Phenomizer) which contains over 6,000 genetic variants for different problems in the babies. The Phenomizer connects symptoms to genetic variants in the system.  So, a doctor can type in the symptoms the newborn is having, and the Phenomizer will give back a number of genes that may be causing the issue.  These genes are sequenced and tested from the newborn to see if there is a mutation within the gene that matched up for those specific symptoms.

Normally the sequencing process takes about 50-60 hours, but with this more rapid technology, this is cut down into less than half.  The 26 hour process was tested on infants who already went through the longer 50-hour sequencing process and were diagnosed. The 26-hour process resulted in 99% accuracy linking to the same mutations as the 50-60 hour process.  The cost of this test is $20,000.

I think that when it comes to determining the diagnosis of a newborn, time is critical to the newborns health.  Diagnosis is needed in a timely fashion in order to prevent the problem from progressing and causing further health problems.  By cutting the time of sequencing in half, genetic specialists can tie mutations to diagnoses more aggressively.  This new way of sequencing genes and finding possible mutations is so new and there are so few forms of sequencing and analyzing genes, that the cost of this testing is extremely high.  Once further testing is done within the program and more ways of sequencing genes are discovered, the cost should decrease.

Height Is Directly Related to Higher Risks of Heart Disease

          Recently at the University of Leichester,  Professor Sir Nilesh Samani led a study to determine whether shorter height can be directly associated with higher risks of coronary heart disease.  Even though there are other factors that may impact coronary heart disease such as smoking and nutrition, information about other factors wanted to be looked into.  In order to research this, tests observed around 200,000 people to examine whether the 180 genes that are related to height were directly related to coronary heart disease.  The understanding of this test was that if DNA controls height, then it can be directly related to coronary heart disease.  The final results from the testing revealed that the more height increasing variants a person has the lower the chances of disease.  It was found that for every 2.5 inch increase in a person's height, their chances of developing a coronary heart diseased by 13.5%.

          After observing how the difference in a person's height can determine the chances of developing coronary heart disease, other testing started to occur.  Researchers started to look into other factors of coronary heart disease and which could be associated with shorter heights.  They discovered that the only factors effect by short heights were fat levels and cholesterol.  This was the first study to show association between short heights and heart disease.  With further exploration, it can allow for new ways to reduce risks, new ways for prevention, and new treatments.

          This seems to be a great place for more research and exploration because with new knowledge of a shorter height being related to heart disease it may be possible to look into prevention and start treatments earlier.  Testing early may be able to become more common in patients of shorter heights, especially if other family members have experienced heart disorders in the past.  

Original Article

Supporting Article

The Genomic Key to Memory

Have you ever thought that your short-term memory was just really bad? Forgetting the name of someone you just met or where you put your keys are common slips in memory that haunt most of us at some point in our lives. For certain individuals these issues will continue to progress with age and lead to signs of detrimental conditions such as Alzheimer's disease. A new study led by Prof. Ian Deary of the University of Edinburgh in the UK identifies specific genes that are linked to poorer memory in life. This was the first international study that found a link between common genetic variants and the ability to recall lists of words and stories.

The study used data from five studies conducted at the University of Edinburgh: the Lothian Birth Cohort 1921 and 1936. Altogether these made up the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium, which analyzed data from 30,000 individuals over the age of 45. The participants, all free of dementia, underwent memory tests that involved recalling words and stories after an assigned time period. It was found that individuals with certain genetic variants had signs of early Alzheimer’s in their brain tissue. The researchers analyzed the results with personal genome data to determine genetic variants and changes that were inked to lower memory.The results show that individuals with lower overall scores had variants near a gene called Apolipoprotein E and other gene involved with immune responses. It should be noted that previous research indicated that some forms of Apolipoprotein E are linked with increased risk of dementia, including Alzheimer's. The researchers also checked 725 postmortem brain tissue samples and determined that individuals with the genetic variants that related to poorer test scores were more likely to have signs of early Alzheimer's disease.

The genetic variants associated with memory performance also predicted altered levels of expression of certain genes in the hippocampus, a key region of the brain for the consolidation of information. This really is an interesting study for me because I do feel like I have really bad memory, and I’m young. I don’t personally have any relatives that suffer from diseases such as Alzheimer’s but the fact that the genes associated with it can be identified can lead to revolutions in the medical aspect. This can help lead the path to new preventative medicines. The data from this study from the memory test can be used in future studies as well.

A Certain Gene Increases the Progression of ALS

        Amoytrophic lateral sclerosis is a disease that involves the degeneration of the lower and upper motor neurons of the brainstem, resulting in those with the disease to loss of muscle control and ultimately death. One third of ALS patients are believed to have a gene that causes a faster progression of the disease. When mice were given this genetic variant, the disease progressed faster and the mice died sooner than the mice that did not have the genetic variant.
       
        About 10 years ago, researchers at Penn State found a link between the amount of iron accumulation in the brain in patients with nuerodegenerative disorders (Parkinson's and Alzheimer's disease). These researchers also found that about of third of their ALS patients had an accumulation of iron and had a genetic variant, HFE, that is associated with iron overdose diseases. In order to test the relationship between iron accumulation and the HFE variant, researchers crossbred mice with the HFE gene and standard mice.

This picture shows the difference between normal nerves and how the nerve fibers start to deteriorate and muscles weaken in those who have ALS.

        When studying the mice, James Connor, vice chair of neurosurgery research and director for the Center for Aging and Neurodegenerative Diseases, and his team found that the crossbred mice performed worse on test for hind limb and forelimb strength and had a 4% shorter life span. Their observations led them to conclude that when a mouse with the HFE variant was infected with ALS, the disease progressed much more rapidly than in the mice that did not have the variant. The grad student that was running the study, Wint Nandar, also realized that the females' disease progression was much faster in females with the variant than in males; however, normally, males with the disease would die faster than females.
 
        The researchers also found that the infected mice showed a greater degree of oxidative stress and microglial activation. Microglial cells are normally responsible for repairing the body, but when they are over-activated, they can cause inflammation, a factor that does not help with the progression of the disease. The mice with the genetic variant were also seen to have a disruption of the nuerofilaments, fibers that transport nutrients through the nerve cells, another reason why the disease can progress faster when HFE is present.

          I think that this a very important study that can be very valuable to those that are trying to find a cure for ALS, or some type of treatment. Knowing the genetic background an individuals can help researchers determine why some of their products work for some patients and not others. ALS is a very detrimental disease and anything that is going to hep researchers get a better understanding of the disease would be extremely beneficial.

Original Article: Genotype found in 30 percent of ALS patients speeds up disease progression

Genes Active in the Brain of Rats Show Aggression or Tameness

In the journal, GENETICS, research has been published about the differences between aggressive and tame rats and how it is caused by the genes in their brains. This study can further previous research about what genes make animals tame. It shows us which genes make tame dogs and their wild ancestor, wolves different. According to co-author Henrike Heyne of the Max Planck Institute for Evolutionary Anthropology and the Unviersity of Leipzig in Germany, all domestic animals are tame and this research allows us to understand the reasons why wild animals transform to domestic animals.

Dmitry K. Belyaev, famous for his work on experimental domestication on foxes, and his colleges used 200 descended rats from a study he did over forty years ago. The purpose was to separate the rats into two groups: ones that show aggression and fear and ones that are tame and friendly. The groups were based off of when a human hand approached the rats: aggressive rats attacked and showed fear towards the hand while the others were intrigued in the hand and allowed the hand to pick them up.

The researchers created a population of hybrids by crossing the rats from each group to find gene variants responsible for the differences in behavior among the rats. The hybrid rats showed "a wide range of behaviors and inherited a random mix of genetic variants from the original tame and aggressive parent rats." Eight regions were identified in the genome by the research team which signified genetic variation in the tameness gene. Heyne and colleagues analyzed brain activity to discover that eleven genes in these regions made them "more active in the brains of aggressive rats compared to tame rats, or vise versa." Five of these eleven genes were noted to influence behavior of the rats, which may be the driving force of differences between the two groups of rats. "Several of the genes are involved in nervous system development, and one, Slc17a7, has previously been implicated in fear and stress behavior in mice."

Although further research is needed to determine which genes specifically trigger aggression and tameness in mice, this experiment gives us great insight for the possible outcomes. According to Mark Johnston, Editor-in-Chief of GENETICS, this work done allows us to better understand "genetic details of a biological process that has been pivotal to human history." If we are able to identify which genes cause aggression and which genes cause tameness in mice, there is a great possibility that many wild animals will be tested on and domesticated. If the testing is allowed, humans will most likely figure out a way to control wild animals and breed them in ways that are beneficial to us. On one hand, this concept is mind boggling to think that this may be able to be done with technological advancements. Many people will probably have exotic pets, and try to advance one another to  have the most "unheard" of animal as a pet, which could get out of hand. This advancement can devastate wildlife as we know it and completely change the way we interact with nature: our idea of nature will be man-made at that point.

Article:
http://www.medicalnewstoday.com/releases/285139.php

Related Article:
http://www.genetics.org/content/198/3/1277.long

New DNA Sequencing Method

     Genetics has come a long way in the past few years, but a new discovery by Evan Eichler, a professor of genome sciences at the University of Washington, and his colleagues, have discovered many new genetic variants by using new genome sequencing technology. The technique is called single-molecule, real time DNA sequencing (SMRT). Researchers may now be able to identify the genes and genetic mutations in some portions of genome mapping that have eluded scientists. Ultimately, this advancement in genetic mapping may explain the underlying genetic causes of some diseases and conditions.

Example of SMRT sequencing for 5-hmC gene.

     Standard genome sequencing methods are able to map about half of the genome precisely enough to know the genes related to about half of all known heritable diseases. The current way of mapping DNA involves cutting out small snippets of the DNA sequence and overlapping the segments and analyzing the sequence to map the genome. Even though this methods is very accurate and scientists have been able to identify many variation this way, they have been unable to use this method to detect variation that are 50-5,000 bases in length, leaving this part of the genome unknown to everyone.

      SMRT technology allowed Eichler and his colleagues to sequence and read DNA segments that are longer than 5,000 bases, something that cannot be done with standard gene sequencing technology. This technique allows researcher to create a much higher resolution and more well-structured map which leads to being able to detect more structure variation in base pairs. The researchers tested their new approach by doing the genome sequence of a mole. They were able to identify and sequence 26,079 segments that were different from the human genome and 22,000 of these variants had not been reported before. These results show that there is a lot of variation in the human genome that researchers can currently be missing. They were also able to identify 160 genome gaps that were not known before, close 50 gaps, and narrowed 40 others.

      I think that this is a very big advancement in DNA sequencing that will prove be extremely useful in the years to come. Being to to be more specific and uncover hidden genetic variants that can help identify the causes of certain diseases will be extremely helpful to the public, researchers, and doctors. The identification of more genetic variants will help us achieve and even better understanding of the human genome and will have very important, valuable implications for the future of disease diagnosis and prevention.

Original Article :New technology closes many human genome mapping gaps that have long resisted sequencing

The Genetics of Human Height

In a recent study, data from the genomes of 253,288 people were analyzed by researchers to determine the number of genetic variants and genome regions relating to height.  The height of an individual is estimated to be 80% genetic.  Environmental factors and nutrition are thought to account for the rest.   Based on results, it was determined that there are nearly 700 genetic variants and more than 400 genome regions relating to height.  It is important to note that over 2 million common genetic variants were scrutinized.  Scientists claim that humans on average have become taller over the past few generations because of environmental factors as well as improved nutrition.

  The image above displays the world's tallest man (8'1'') 

with the world's shortest man (2'5'')

Scientists say they study height for two main reasons.  Dr. Joel Hirschhorn, a geneticist and pediatric endocrinologist at Boston's Children's Hospital stated, "For over 100 years, it has been a great model for studying the genetics of diseases like obesity, diabetes, and asthma which are also caused by the combined influence of many genes acting together.  So by understanding how the genetics of height works, we can understand how the genetics of human disease works."  Researchers believe that many genes identified in the study are probably related to skeletal growth.  Several genes were related to collagen, chondroitin sulfate, and growth plates.  The same team of researchers conducted this study in 2010, but by doubling the sample size this time, they were able to double the number of known gene regions that are associated with height.  Researchers believe that knowing genes and their variants that are important in height may help doctors diagnose individuals in the future who have a single major underlying cause.

As an individual who aspires to enter the medical field, I find it fascinating that understanding the genetics of height gives more understanding to how the genetics of human disease works.  The correlation between the two is nothing short of remarkable.  I also find it interesting that by doubling the sample size, scientists were able to double the number of known genome regions relating to height.  This is a huge step forward in not only understanding the genetics of height, but also for understanding the genetics of human disease.           

Article [1]: http://www.businessinsider.com/r-tall-tale-scientists-unravel-the-genetics-of-human-height-2014-10
Related Articles: http://guardianlv.com/2014/10/genetics-study-of-height/
                          https://time.com/3462490/new-genes-found-that-determine-your-height/