Discovery of Prehistoric DNA gives an insight of Greenland’s Ancient Habitat

         In December 2022, scientists detected remnants of DNA located in Greenland's Arctic region. A fascinating discovery made by scientists from Denmark of prehistoric DNA, believed to be in existence from around a million years ago, identifies organisms that once inhabited Greenland. According to Nature, the DNA is the oldest ever to be found and sequenced. From the sequencing of the DNA fragment, research entails that the DNA is linked to hundreds of different organisms. Among these organisms, plants and animals, noted to have migrated from Greenland, such as birch tree and horseshoe crabs were linked to the DNA found in Greenland’s icy climate. In addition, a new discovery of mastodons, a prehistoric mammal species, was also detected on the DNA fragment. Scientists entail the discovery's impact on paleontology and predict that this new DNA discovery could be a gateway to understanding life that existed millions of years ago.

        

Epigenetics in Identical Twins

 

A new study done by researches from the Washington State University have found that exercise can change genetic markers of the metabolic diseases, which affects any diseases or disorders that disrupts normal metabolism. Even though identical twins should both have the same genomes, as they grow older they can still develop different diseases. Epigenetics which is the study of how your behaviors and environment can cause changes that affect the way your gene works is the one reason for this. When exercising, epigenetics affects a lot of different types of cells many whom are involved in metabolic diseases. The test undergone on about 70 pairs of identical twins who partake in this exercising experiment was given fitness trackers and had BMI taken. They found that the more active sibling based off of waist size and BMI had lower signs of metabolic disease.

Interesting how identical twins who have the same DNA can end up developing different diseases than their counterpart due to things such as environment. Another article talking about identical twins risk for different dieases can also help explain how this situtation can occur too. Such as genetic changes to one part of the body or function can cause an increased negative effect towards that part of the body/function.

Yaks That Adapt to Low Oxygen Environments

There has been recent insight into adaptations, genetically and cellularly, that allow yaks to survive in high altitude environments. It has been determined that this ability to live in these kinds of environments could be a result of endothelial lung cells specific to yaks. The endothelial lung cells are a single layer lined with blood vessels that regulates the exchanges between the bloodstream and surrounding tissues. High altitude regions in the Tibetan Plateau are inhabited by both domestic and wild yaks. They experience low oxygen concentrations. Humans and other non-native mammals would experience extreme heart and lung issues if exposed to such low oxygen conditions. This is not the case for the yaks who have adapted to these conditions over millions of years.  

A group of scientists explored just how yaks are adapted to these kinds of environments by combining transcriptomic and genomic data to present an exclusive genome assembly for both domestic and wild yaks. Transcriptomic data involves characterizing all transcription activity (both coding and non-coding) or a select subset of RNA transcripts within the sample. This analysis allows for the identification of candidate genes and expressed markers of traits of interest associated. This also included a map of the different lung cell types present. 127 genes were identified to be expressed differently in yaks compared to European cattle and identified a subtype of endothelial cells only found in the lung tissue of yaks. This specific cell type was shown to express genes involved in high altitude adaptation. These findings on genetic adaptations of yaks and high-altitude environments can be useful for future studies on how other mammals respond to low oxygen environments.  

Single Nucleotide Polymorphism analysis determines origin of domesticated cats

 

A recent study at University of Missouri-Columbia used genetic analysis to determine the origin of the first cats to be domesticated by humans. Genetic markers were assessed from nearly 200 cats from regions, varrying from the Fertile Frescent region to areas of Europe, Asia, and Africa. The results strongly support the theory that cats were originally domesticated exclusively from the Fertile Crescent region. The results of this study will be used for further genetic experiments in veterinary medicine, for research into treatments of genetic diseases.

I found it interesting to read how this could be used to benefit veterinary medicine. Leslie A. Lyons, who performed this study, referred to this as "building genetic tools" to improve medicine for cat health. That idea of genetic tools is intriguing, but also a little existentially scary. It is fascinating to speculate what this could be be used for. The article mentioned that they are working on developing treatments for polycystic kidney disease. 

Article

Scientists modify yeast cells and turn it into a cannabis tracker

 Researchers at the University of Copenhagen have modified a baker's yeast cell and replaced it with a sex drive that causes the cell to turn red when it detects cannabis. This modification can detect not only cannabis, but molecules with similar functions to cannabinoids. Humans use GCPRs (G-Protein Coupled Receptors in order to taste and smell. The researchers of this study used these same receptors in order to create the signal. 

In a singe day of testing this receptor, researchers found four new substances that had not been discovered, but could potentially be used for anti inflammatory purposes or pain relief. 

I am interested to see how this study develops, it seems like the sensor detects so many different substances that it might not be useful for testing for cannabinoids, but I think it could potentially help detect alternate uses in different substances. 

https://www.sciencedaily.com/releases/2022/12/221208114816.htm

Smoking and Drinking Potentially Linked to Genetics

 

Drinking and smoking have been potentially found to be genetically linked in a recent study published in Nature. The researchers found more than 3,500 genetic variations that potentially affect smoking and drinking behaviors in a genome-wide association study. This study included almost 3.4 million people with African, American, East Asian, and European ancestry. Of the 3.4 million people, 21% had non-European ancestry.

The researchers identified 3,823 genetic variants that were associated with smoking or drinking behaviors in individuals. Of the more than 3,500 variants, thirty-nine were linked to the age at which individuals started smoking, 243 were linked to the number of cigarettes smoked per day, and 849 were linked to the number of alcoholic drinks consumed per week.

In my opinion, although these behaviors may be genetically linked, smoking and drinking are still environmentally influenced. The genetics part could be more so to do with how one reacts when they do smoke and drink. The genetic links could also affect how easily the risks of other health conditions arising from drinking and smoking, as smokers are more likely to develop heart disease, strokes, and lung cancer. Likewise, drinking can lead to the development of multiple chronic diseases, such as high blood pressure, heart disease, cancer, and multiple mental health issues and memory problems.

 

   Bones from a cave found in southern Siberia Russia, have led to the discovery of one of the oldest known Neanderthal family. Researchers have identified that this Neanderthals family consisted of a father, his teenage daughter, and others who were also closely related, presumably cousins. DNA extracted from the bones and teeth of the group/community has led to some suggestions on how theses ancient people formed groups. They were smaller in size and found that the females often migrated from their own group to follow their partner's. Since mitochondrial DNA is commonly inherited from the mother and showed greater distinction compared to the Y chromosome from the males, also helps conclude that the females migrated while the males stayed within their own group/community.

 

Link to articles ~

Article 1

Article 2

Article 3

 

Crohn's Disease Triggered by Bacteria Genetic Changes

A new study by Weill Cornell Medicine and New York-Presbyterian investigators found that certain changes in a gene can allow harmful bacteria in the stomach to cause inflammation that drives Crohn's disease. The host gene, AGR2, encodes part of a cell's machinery that helps prepare newly made proteins to properly repel "bad" bacteria. When the process is disrupted, protein production gets backed up and causes the cell to become stressed. The cell's stress response plays a central role in the development of Crohn's disease. Crohn's disease is a type of inflammatory bowel disease (IBD), which causes inflammation in the digestive tract. This may cause abdominal pain, severe diarrhea, fatigue, weight loss, and malnutrition.

In a different study, researchers were able to genetically engineer mice to prevent the expression of the AGR2 gene and discovered that they developed Crohn's-like inflammation. This caused them to link the inflammation in that study to adherent-invasive E. coli, or AIEC, which were found to be bacteria implicated in Crohn's disease. In this study, they were able to connect that changes in the AGR2 activity levels with increases in the bacteria group that AEIC belongs to. They ended up discovering that the inflammation that was kicked off by the interaction was linked to the production of IL-23, an immune signal that is an important driver of inflammatory bowel disease (IBD) and colorectal cancer tumorigenesis and is also an important therapy target.

In my opinion, I find this research interesting in how this research could affect treatment and medication for this type of disease. If Crohn's disease is triggered by AEIC, I wonder if other digestive and bowel diseases could be caused by similar bacteria found in the digestive tract and if this research can be used to do similar experiments on other gut bacteria and digestive diseases.

South Americans May Have Traveled to Polynesia 800 years ago

 Researchers suggest genetic analyses show "....DNA swaps between the voyagers and people on a still-undetermined eastern Polynesian island were followed by the spread of the South American ancestry to other eastern  Polynesian islands" (Moreno-Estrada) It is suggested that many Homo groups lived during the Middle Pleistocene and were "...too closely..." related to have been distinct species. The groups would have eventually mated with each other. However it is not known when exactly during that era, the groups mated and there is no definite distinction (genetically nor phenotypically) in Homo sapiens, Denisovans and other ancient Homo populations. Scientist John Hawks from the the University of Wisconsin-Madison, shares new fossil evidence came from the region of Israel.  molar tooth from the lower jar of an individual found near the site called Neshar Ramla (~140 000 and 120 000 years ago) This suggests that a previously unknown Eurasian Homo population lived at the site. 

To continue, "...back-and-forth..." migrations by Homo groups between Africa and Asia started ~400 000 years ago. Rains had turned parts of deserts into green passages covered, which were identified at a Saudi territory that once hosted hunter-gatherers, whose tools were left behind. Stone tools found at the site (~200 000 years ago) resembles like tools found in Africa (from the same H. sapiens)  To conclude, the route of the groups is shown and it is definitely a reason that migration has occurred. However, one should not assume this is could be the only reason. Further research must be conducted. 

Sites in the Brain Where RNA Is Edited Could Help to Better Understand Neurodevelopment and Disease

 

Researchers at Mount Sinai have determined new avenues for understanding molecular and cellular mechanisms of brain development and how they affect both disease and health by cataloging sites in the brain where RNA is modified. As an individual ages, the RNA editing rate in the brain increases. This modification happens throughout one's lifetime through a process known as adenosine-to-inosine (A-to-I) editing. With this they could explore the implications across a range of aging and neurodevelopmental disorders. Because there are so many already identified A-to-I sites, it can be difficult to determine which sites are physiologically important. The researchers were able to narrow it down to about 10,000 sites that have potential functional roles from early fetal development through advanced aging. These sites will help get a better understanding of brain neurodevelopment through a lens of A-to-I RNA modifications.  

While DNA is widely known as the genetic blueprint of all human and other living things, RNA is responsible for carrying out the instructions to create functioning proteins. When modifications accumulate on RNA, it can alter the way a protein functions. These A-to-I changes are introduced by a group of ADAR enzymes whose edits have been known to have an important physiological role in early fetal development by regulating neuronal signaling and synaptic transmission. All of this shows that in the course of a lifetime, thousands of individual edits will accumulate in the RNA in the brain and will likely produce functional ramifications as a person ages.  

The data collected by the Mount Sinai study was from more than 800 individuals covering all stages of pre and postnatal development. The broad data can create a timeline to depict how A-to-I editing changes over time. The work uncovered by the researchers can now provide many avenues for future studies and offer insight into the role of RNA editing in the promotion of health and disease.  

Feline genetics help pinpoint first-ever domestication of cats

 A study at the university of Missouri has determined how long ago cats were domesticated. Leslie Lyons, a feline geneticist, has studied about 200 gene markers in cats from around the world to help pinpoint this domestication. One of these gene markers was microsatellites, which are quickly mutating. 

For a lot of other domesticated species, it seems that they have had multiple domestication events over the years, while cats seem to have been domesticated once, about 10,000 years ago, as humans began to migrate. When humans began to migrate, it seems they felt the need to bring cats with them, which I can't blame them for. 

Cats are also referred to as "semi domesticated" because although cats do well in human care, if they were let outside on their own, they could fend for themselves and hunt just fine. 

https://www.sciencedaily.com/releases/2022/12/221205121616.htm

Enormous fern genome

  

"Strange Tree Fern Has a Surprisingly Enormous Genome", ferns reproduce similarly to mushrooms by releasing clouds of spore and split from seed baring plants millions of years ago. Fern genomes are very large and were just fully sequenced fairly recently. A large genome genome adds opportunities for advantageous mutations that buffer from undesirable ones. Researches found which genes build the ferns trunk-like stem and provided insight on how key traits evolved in stemmed plants. In addition, in the article, "Scientists Sequence Genome of Flying Spider-Monkey Tree Fern", it is discussed how knowing their genomes and how tree fern species are being overexploited in combination with climate change and threatens their survival. Not only did they just fully sequence their genome they used biochemical methods to measure the levels of lignin and secondary metabolites. 

Sequencing species genomes is important to linking other species and finding their relatedness. Not only does knowing their genomes allow for further research it allows us to determine hereditarily from the ancient plants. 

Gene Disccovered to Improve Drought Resistence in Wheat Crops

 A team at John Innes Center, working with international researchers, found a gene which could help increase wheat production in areas with dry soil conditions. Wheat crops are already being selectively bred to be shorter. The shorter height of the stalk means that more resources are being invested into grains, and also decreases the likelihood that the stalks are destroyed before harvest. Shorter wheat crops that are currently being used are more effective at growing in dry soils, with the disadvantage that they must be planted deeper into the soil, causing more of the plants never to sprout. The newly discovered Rht13 gene circumvents this issue, because the affected area is higher up the stem of the crop.

This is a really interesting discovery, given the current predicament with climate change. More frequent and more severe droughts and other natural disasters are happening, and ill continue to happen due to climate change. Droughts in particular threaten agricultural production. The discovery of this gene will help mitigate the impacts of climate change. Drought resistant crops are going to be essential in preventing wide-scale disasters in the future.

Article

COVID-19 and Loss of Smell

Many individuals diagnosed with COVID-19 typically also suffer from the loss of taste or smell. According to an article, researchers have now pinpointed the genetic variants in humans suffering from losing different senses. A study was conducted with nearly 70,000 adults with COVID-19 and found that individuals with specific genetic mishaps on chromosome 4 were eleven percent more likely to lose the ability of their senses, whether taste or smell, than those individuals without the changes on their chromosome. The two genes, UGT2A1, and UGT2A2, help humans smell and happen to reside in the region of chromosome 4 that is linked to sensory loss during infection, found by Janie Shelton of 23andMe. Both of these genes make enzymes that metabolize substances called odorants, producing distinctive smells. 

For me, when I had covid, I lost my sense of smell, and I know a few other individuals and family members who have as well. I also do remember that news reports did suggest that one of the symptoms of COVID-19 is losing the sense of smell but I never heard of anyone loosing their sense of taste. When being sick many people loose their sense of taste especially if one has a sore throat. I believe more research may have to go into this study to se exactly how we loose our smell or taste for some individuals. 

Using CRISPR/Cas to suppress chromosomes in genetically modified plants

 An article from ScienceDaily discussed research being done in regards to challenges when genetically modifying plants and crops. The location of genes on a chromosome greatly impacts how they are passed on. The closer they are together, the more likely they are to be linked and inherited together. However, genes that are farther apart are more likely to get separated. In agriculture, there are a plethora of favorable traits that farmers and geneticists are trying to breed for. For example, they want the crops to have high yields, taste good, be nutritious, and more. Unfortunately, the genes involved in these traits are not always close together on the chromosome.

In order to combat this issue, researchers have been working on a solution based on CRISPR/Cas. They used this molecular scissor to cut the middle portion of genes that are in between the favorable traits they want. They then invert the sequence and put it back in. This essentially deactivates the middle portion of the chromosome. During the breeding process, the deactivated portion acts as though it is invisible or not really there. The resulting effect is that the favorable genes they want now appear to be right next to each other and are more likely to be linked and passed on together.

I think this is a really important discovery in the agricultural field. As population size increases, we need more and more food. If we can grow more crops more quickly and reduce susceptibility to disease, the chance of feeding future generations will greatly increase In addition, if we can develop crops that taste great and have a high nutritional value, we can improve the overall health of our societies.

Loss of Y Chromosome Can Cause Increased Risk of Heart Disease

 

The loss of Y chromosome causes an increased risk of heart disease. A study was done on male mice who were genetically engineered to lose their Y chromosome. It was shown that when these mice no longer had the Y chromosome in their blood, scar tissue began to build up in their heart which led to heart failure. There have been studies in the past done by Dr. Walsh about how losing the Y chromosome causes different medical conditions in males. He still was trying to find out what caused this, so he continued his study on the mice, which showed a direct cause and effect relationship with heart, kidney, and lung disease. This can also be the cause of shorter life span for men. It was concluded that the loss of Y was due to cell division and eventually disintegration of Y chromosome in the blood.

 

This study is important because heart disease is one of the leading causes of death. If they can pinpoint where this issue is coming from then they can research solutions. This was very interesting because I did not know this could be a major cause of heart disease. Overall this was a good article and very informative.

Quantum Biologists find that Enzymes could be Key to Understanding DNA Mutations

    

Credit: Dan Bishop, Rowan Sigaev, Sergey Nivens

    Researchers from Surrey’s Quantum Biology Doctoral Training Center found that DNA replication happens 100 times faster than previously thought due to quantum effects in this article. As quantum effects in biology is a relatively new study, many new findings are coming out regarding their impact on biological processes. At this speed, it is theorized that quantum effects could impact the DNA replication process causing mutations. One enzyme is responsible for quantum effects being able to take place, helicase. During DNA replication the two DNA strands need to separate. Helicase is responsible for this separation and was previously thought to be a slow process. If this process was as slow as initially thought, point mutations would not be able to survive the replication process. Researchers have now found that the opposite may be the case, and helicase could be causing the mutations to stabilize instead. Quantum physics, computational chemistry, and other specialized fields within physics, chemistry, and biology are all looking to answer questions about quantum effects. This could lead to a better understanding of point mutations and possible prevention of such mutations in the future.

Genomic Study of S. flava Leads to Insight on Evolution of Herbivorous Insects

Herbivorous insects make up roughly 25% of all animals on Earth. In an effort to understand them better researchers did a study on Scaptomyza flava, a fruit fly species of the family Drosophilidae. They are leaf-eating insects which use their ovipositors, or egg laying organs with valves that open and shut like jaws and tough, tooth like, bristles to cut into and scoop out their food. It mimics a mouth. Some scientists hypothesized that the development of organs like the ovipositors were central to the evolution of herbivorous leaf-eatering flies, like S. flava. To figure this out researchers tried to learn how changes to the ovipositors corresponded to flies' feeding habits and diet. They found that bristle number increased with the emergence of plant eating millions of years ago. They also wanted to learn more about how insects started eating plants and this study was done by sequencing these flies' DNA. The team found candidate genes thought to be responsible for the development of these "toothy genitals", as the article calls them. 

I was surprised to learn there is more than one species of fruit flies. There are other kinds of fruit flies other than the ones we work on in labs. I was also surprised how important a feature, this weird and small organ, is to these biologists. How important the study of the ovipositor is to better understanding herbivorous insects. I am glad that this DNA study was their first step towards understanding the "genetic basis of this trait," as well. 

Early Life Experiences Can Impact Longevity and Activity of Genes

 Credit: Unsplash/CC0 Public Domain

    Fruit flies were used to test the impact of early life experiences, as early as in the womb, on their health later in life. They found that changes in gene expression during their youth formed a “memory” that impacted their health later in life as seen in this article. In their test, they fed fruit flies a high-sugar diet early in life. Despite changing to a healthier diet later in life, they lived shorter lives compared to the control group. The reason for this was due to dFOXO, a transcription factor involved in glucose metabolism known to affect longevity. These researchers then increased activated dFOXO levels in female fruit flies for the first three weeks of the fly’s adulthood. This caused changes to the fruit flies’ chromatin, resulting in a different expression of genes later in life. This improved their life expectancy by counteracting some changes that would normally take place during the aging process more than half their lifespan later. If these findings are applicable to humans, this could drastically improve life expectancy by finding the causes of age-related diseases, and potentially counteract damage already done during childhood or in the womb.

2 Cancer Patients Remained Cancer Free After CAR-T Cell Therapy

 

Cancer immunologist used an experimental immunotherapy called CAR-T Cell Therapy, on 2 patients in 2010. Patient with the blood cancer, leukemia, had their immune cells genetically engineered which were able to track down the cancer cells and kill them. Both patients remained cancer free for over a decade. Therefore, this treatment is promising for future treatment of cancer. However, the treatment does not work on everyone and can even have some dangerous side effects. Researchers are still studying the mechanism of this treatment in hopes of being able to adjust it so it can treat more people.

 

This is a very important study for cancer research. Using gene therapy can cure cancer instead of just having remission. It also can help with people not having to use radiation or chemotherapy for treatment which can have serious side effects.

New Genetic Link Between IBD and Colorectal Cancer

In October, an article was published that described a new discovery in regards to the connection between inflammatory bowel disease and colorectal cancer.. Scientist have already noticed that those with IBD are at a significantly higher risk for developing colorectal cancer. They have even discovered a couple disease causing factors including E. coli, but wanted to learn more. So the researchers analyzed over a hundred gut bacteria from patients with IBD and filtered out any that caused DNA damaged. From these, they found a bacteria that was not one of the previously discovered. They named these indolimines. When tested in mice, indolimines not only damaged DNA, but promoted tumor growth. When researchers blocked or inhibited indolimines in mice, they were able to suppress tumor growth.

This discovery adds not only other potential link between these two diseases, but also suggests possible mechanisms for treatments. By finding more DNA damaging gut bacteria, doctors and scientists could eventually start to screen patients for these in order to better understand their risk for colorectal cancer. However, the article also mentions how there is a lot of intermediate steps that need to be taken because the gut biomes of humans are far more complex than those of mice. As a result, we might not find the same effects. More research and trials have to be done, but it is still an exciting discovery.

The expansiveness and complexity of genetics is very fascinating to me. Here there are so many different bacteria and other factors that could link IBD and colorectal cancer - and these are just the ones found so far. However, from a humanity perspective it kind of sucks because it makes treatment and possibly cures very difficult to design since everyone's diseases may be caused by different pathways.

Gene Linked with Autism Plays Critical Role in Early Brain Development

 

Credit: Camilo Ferrer

    The gene GABRB3 plays an important role in early brain development and may shape the formation of normal and atypical nerve connections in the brain as described in this article. This gene is linked to a drastic increase in the risk of developing ASD (Autism Spectrum Disorder) and another condition called Angelman Syndrome. Many symptoms of these conditions can be partly attributed to atypical connections between neurons in the brain. GABRB3 encodes for part of a critical receptor protein that helps maintain order in the nervous system. It also helps determine how brain connections form during development. Testing on mice was done and determined that mice lacking the GABRB3 gene did not form the normal network of connections between neurons in the specific brain region responsible for sensory processing. These mice were also hypersensitive to touch, suggesting the neurons affected were more responsive to sensory stimuli. These results were compared to examinations of human neuroimaging data. They found a correlation between the spatial distribution of the human GABRB3 gene and atypical nerve connectivity in individuals with ASD. This research could better help diagnose and treat those with ASD or similar conditions in the future.

A Call to Diversify Genetics based Research

            

    The exclusion and misrepresentation of minorities is a common occurrence seen in many disciplines of medicine and science. These exclusions are made evident in an interview conducted by Science news's editor Erin Garcia de Jesus with geneticist Tshaka Cunningham. In the interview, geneticist Tshaka Cunningham highlights the issues pertaining to genomic research both historical and currently. These issues revolved around the ethnic distribution of participants who were involved in the research trials centered on gene therapy and precision medicine. According to the GWAS Diversity Monitor, genomics research has encompassed a majority Caucasian population, which make up nearly 95% of participants. Cunningham argues that the participant distribution seen in gene studies relating to precision medicine are highly controversial and are not applicable to minority populations such as Blacks and Hispanics who represent less than 1% of participants. This argument imposed by Cunningham brings to light the disparities within genetics research, and why genetics research and advancements made in treatments of diseases is geared more to Caucasian populations. To conclude the interview, Cunningham talks briefly on initiatives he is currently making to change this disparity and encourage more African Americans to be involved in medical research. These initiatives are centered around educating more Black Americans on the benefits that their contributions as participants of research trials can serve in innovations made in the field of genetics and modern medicine. 

     I feel the information given by geneticist Tshaka Cunningham provides a different interpretation on the context of genetic research. His arguments purposed against the applicability of new discoveries in medicine and treatment to the Black population are both insightful and enlightening.

Viral DNA in our genome

 

Aidan Burn discusses in the article "How the Ancient Viral DNA in Our Genome Affects Disease and Development", how remnants of DNA from past pandemics are being seen in the human genome of healthy individuals. More specifically, human endogenous retroviruses are around eight percent of the human genome as a result of infections from ancestors and became part of the genome during replication. However, some ancient retroviruses were not typically passed from generation to generation but some gained the ability to infect germ cells that pass their DNA to future generations. In addition, "Human Endogenous Retroviruses Are Ancient Acquired Elements Still Shaping Innate Immune Responses", depicts how human defenses should prevent HERV medicated immune activation, however, HERVs are still able to modulate and be influenced by the individual's immune system which implies a central role in the evolution in the human innate immunity. It was detected that HERV genes were in tumors and diseased tissue as well as human embryonic development but it was not determined its role in healthy tissue. For example, syncytin which is a HERV embedded in mammal genomes, is a gene derived from an ancient retrovirus that plays a large role in the formation of a placenta during pregnancy. 

Knowing the role of human endogenous retroviruses in the human genomes is crucial for the future healthcare system and developing medications. Although, it is not determined the role they play in healthy tissue the role they play in diseased tissue is something that can be used advantageously for producing new drugs to target diseased tissue. Finally, I found it intriguing how eight precent of the human genome contains DNA "foreign" to humans. 

Designing and Programming Living Computers

 

    Graduate students and researchers from Technion and MIT collaborated to produce cells designed to perform computations similar to artificial neural circuits as explained in this article. A plasmid was inserted into a cell, acting as an artificial neural network. This was made possible by altering the plasmid’s genes, giving the plasmid the ability to activate and deactivate those genes due to stimuli. This is similar to how computer code works. Computer code consists of 0/1 switches, and the combination of those switches allows for different functions to be performed. The presence or absence of a molecule in a cell can act as a switch and perform similar functions. A cell can then be “programmed” to perform a function or set of functions such as the OR or AND functions. Artificial intelligence algorithms were also used to reduce the time and cost of genetic modifications to bacterial cells, making this technology more accessible. This technology is in a very early stage but has shown great potential to improve the dosage and effectiveness of cancer immunotherapy and diabetes drugs amongst other things.

Why Don’t Elephants Get Cancer?

 

When organisms have a large number of cells, then there is a higher chance that there will be a mutation. This is not the case for large mammals, such as elephants. The P53 gene is found in a lot of mammals, including humans. This gene repairs DNA replication errors, which prevents mutations, which prevents cancerous cells from growing and spreading. It also prevents cancerous cells from turning into tumors by pausing division of cells. Humans have one copy of this gene, while it was recently discovered elephants have 20. This means that elephants can produce 40 proteins that can help elephants prevent cancer in their bodies. Cancer develops in humans when mutations prevent P53 from working. In elephants, P53 also responds quickly by molecular triggers, so it is able to quickly detect when mutations occur. 

Scientists took blood samples from elephants to observe how P53 interacted with damaged cells and compared the interactions to human P53 and damaged cells, which could be a breakthrough in understanding cancer. Perhaps there is a ratio of body size to the number of P53 genes found that determines how many P53 genes mammals will have. If P53 genes were inserted into humans, then this could reduce the chances of someone developing cancer. Another idea that I thought of relates to an exercise in Genetics Lab. When skin color was discussed, it was discovered that people with ancestors that had a lot of sun exposure had more melanin production. The melanin production protected the skin from UV rays and allowed folate vitamins to be produced when a woman was pregnant so that babies would survive. Maybe elephants were susceptible to cancerous mutations caused by UV light, and elephants with more copies of P53 were naturally selected.

Founder Event Affects Genetic Variability In Ashkenazi Jewish Populations

Photo by Maayan Nemanov on Unsplash

Excavation of an old storehouse in efforts to build access ramps led to unearthing a medieval Jewish gravesite in Erfurt, Germany. From there, archaeologists were able to collect bags full of molars, bicuspids, and incisors from the bones of the dead buried there. Geneticists extracted DNA samples from 33 teeth. Studies of their DNA reveal how, despite being genetically related to the medieval Ashkenazi individuals of the Erfurt community, modern day Ashkenazim, even if they live worlds apart, have less genetic variation. From this study, scientists, geneticists, and researchers discovered the high level of homozygosity among modern Ashkenazi Jews around the world. The evidence suggests this was due to a bottleneck (founder) event where the original community experienced a reduction in population size and repopulated from the few that were left among them. 

It's inspiring to hear how DNA, whether it comes from a living person, or centuries old individual long buried, has a story, a history to share. The computational geneticist from Columbia University, Itsik Pe'er said it best, "Ancient DNA sequencing is a cheat-code that can take you to places where you don't have information today."