This morning, the first day of February, in my AP Bio class we watched a live presentation by a Genetic Counselor, Brooke Nightingale. This topic may sound familiar, and this is because is connected to last week's blog post (if you haven't already, CHECK IT OUT!).
Brooke is an ex-student of NDB High School and she was in AP Biology too. After High School, she had no idea of what she wanted to do in her future, but she had always been interested in Biology. Brooke went to Cal Poly where she majored in Biology, and then she graduated from Ohio State College, where she found out about Genetic Counseling. Now Brooke is working at Stanford Hospital and is constantly helping people and families to find out whether or not they have a genetic disease and what to do if the answer is positive.
Brooke gave a very deep explanation of what Genetic Counselors do, and she did this by telling us what she normally does in a week. Brooke has "Clinics" three times per week, during which she does prep for clinic and post clinic work. Then she supervises genetic counseling students and teaches in the GC program.
Brooke said that Genetic Counseling is a growing field; in fact, the employment of genetic counselors is projected to grow 26 percent from 2020 to 2030, much faster than the average for all occupations. Genetic Counseling is an important job, and as Brooke said, being a Genetic Counselor means being the "Sherlock Holmes of medicine", since they usually work with people that don't have a diagnosis yet. This job is also very versatile, as Genetic Counselors can work in different settings, such as hospitals, laboratories, non-profits, universities, and the government.
Finally, Brooke discussed with us three of the patients she took care of. Listening to her was very interesting and made me realize how important is to study genetics and to understand what could happen if there is an abnormal gene sequence or an error. I can't wait to know more about specific syndromes or diseases!
“Genetic Counselors : Occupational Outlook Handbook.” U.S. Bureau of Labor Statistics, U.S. Bureau of Labor Statistics, 8 Sept. 2021, https://www.bls.gov/ooh/healthcare/genetic-counselors.htm#:~:text=8%25-,Employment%20of%20genetic%20counselors%20is%20projected%20to%20grow%2026%20percent,on%20average%2C%20over%20the%20decade. Accessed 1 February 2022.
These are diseases that can be genetically inherited and passed down. Unfortunately, in most cases, they are incurable. What if there was a way to detect these diseases before they develop? What if you could take preventative measures before it’s too late? Would you even want to know, or would you want to live in ignorant bliss not knowing the truth of the inevitable?
With the development of gene sequencing technology, it is possible to take a sample of your own DNA to a lab where your DNA can be extracted from your blood and have all 6 billion+ nucleotides read and analyzed. In doing so, your likelihood of developing diseases such as the ones mentioned above will be calculated based on the sequences of nucleotides present in your DNA. These sequences are compared to the sequences of the DNA of other healthy individuals. The more your sequences differ from the other DNA sequences, you probably have a genetic mutation which means that you are more likely you are to develop certain diseases.
I’m really sorry if I scared you! I’ll be honest, when I learned about the topic of genetic disorders I got a little nervous because I myself do not know what I could be at risk for. Frankly, I don’t even want to know. If the diseases I could be at risk for are unavoidable, I would not want to know because that knowledge would probably prevent me from living my life to the fullest. However, I do not discourage any of you from finding out which diseases you are at risk for. There is a saying that goes, “Early detection = early action.”
Check out this trailer forCracking the Genetic Codeif you want to dive a little deeper into the world of genetic sequencing:
Cracking Your Genetic Code – Nova Productions – February 9, 2012
This documentary explores the lives of different people with different diseases who have been treated at the genetic level. Each person has had their DNA sequenced and analyzed for mutations. Once these mutations have been found, scientists were then able to develop a drug to fight the disease. Do any of you remember CRISPR? Scientists can now combine genetic sequencing with CRISPR technology to snip out the incorrect code and replace this code with the correct one. That’s some crazy life-saving technology!
The topic of genes is fascinating and my team and I have been learning about them all month. If you would like to learn more about genes yourself, check out this super cool website that takes you through so many games and simulations to explain every topic related to genetics.
If you would like to discover more about other medical breakthroughs regarding genetic diseases, here’s a trailer for a documentary about a scientist who developed a cure for cancer!
Breakthrough – Jim Allison – April 1, 2019
Works Cited:
“Cracking Your Genetic Code Trailer.” YouTube, 9 Feb. 2012, youtu.be/UPzid88oSFc.
Today in my AP Biology class, we watched a documentary on genome sequencing or reading the genetic code of a genome. Last semester and this unit, we learned about DNA replication and the possibility of mutation through an error in replication, transcription, or translation of DNA or RNA. Even the smallest mutation of a single nucleotide can be fatal in an offspring, but sometimes the mutation can be silent and change nothing. Genetic sequencing enables individuals with an undiagnosable, medical issue to locate the mutated gene in their DNA to then properly diagnose, and hopefully find a cure for, their disease. Although a long and expensive process, Doctors believe, especially for these never-seen-before mutations, that it is better to look through the DNA of a genome and not find anything than to have missed an opportunity to fix the problem. But with more technological advancements related to reading DNA, there is an ethical concern on when altering DNA will be taken too far and whether our genetic code will become the new social security number.
An up-close example of the technology and how genome sequencing looks. The highlighted G could be an example of a mutation (Spencer and Sesay).
New companies, such as 23andMe or Ancestry, provide kits to analyze a patient’s DNA to make assumptions on whether they are prone to or have the gene for any genetic diseases. Although, this form of analyzing genetics is not fully reliable because instead of reading the entire DNA sequence, 23andMe only reads one million letters, which is about 1%. This process of genotyping means that 23andMe takes your sample of DNA, reads about 1% of your genetic information, and assumes what genetic diseases you are most likely to develop, based on unfinished information and barely analyzed genetic code. In contrast, many people have bettered their lives by learning these assumptions of their genetic code because it has allowed them to detect diseases early on in development, preventing further growth.
This same reading of genetic code can even be done in the cells of newly conceived embryos to remove any mutations and inheritable diseases before the baby is further developed and born. This advanced scientific technology sparked the ethical debate of “designer” babies, genetically modified babies with preferred traits. Thankfully, the documentary reassures us that some phenotypes are too complicated to be altered and we seem to be a long way out from choosing our child’s gender, eye color, or height.
A few examples of how people fear we will be able to genetically modify babies in the future to become designer babies (“Editing Humanity”).
Some fear that as reading genetic code becomes even more common, our DNA might replace the use of a social security number, I.D., or fingerprint. In the future, when reading DNA becomes more accessible, we could create even more problems of possibly being judged or discriminated against based on your DNA. For example, your insurance could see in your DNA that you are likely to develop a fatal genetic disease at a young age and can deny you life insurance. Although genome sequencing can be taken out of hand or unethically used, the basis of the technology will beneficially impact many lives by giving hope to undiagnosed patients that research can be done to find the genetic mutation causing their problem to then work towards a solution.
Spencer, Philip, and Abdul Karim Sesay. “Expanding the Capacity of Governments for Genome Sequencing in West Africa.” Tony Blair Institute for Global Change, 24 Sept. 2020, institute.global/advisory/expanding-capacity-governments-genome-sequencing-west-africa. Accessed 24 May 2022.
In class on September 27th, our class attended a live video chat with Joe Grabowski and Imogen Napper about the dangers of micro-plastics and how they affect our enjoyment, especially the oceans. We learned everything from who Imogen is and her works!
Brent Durand/Getty Images
Imogen Napper is a marine scientist who grew up in Bristol, England where she developed her love for the ocean. Her passion turned into her career and she started her journey as a plastic detective. Plastic is made out of a compound of hydrogen and carbon. Many things are made out of plastic because of durability and easy production, and this is where the problem is introduced, overproduction. Plastic is being used when not needed, like single-use plastics in our face washes and clothes, called micro-beads. Society today lives in what Imogen called a "throwaway living" style, where humans waste and reuse single plastics.
She then went into her four areas of study, facial scrubs, clothes, biodegradable and compostable products, and ropes. Facial scrubs contained micro-plastics to help exfoliate and cleanse the skin, after explaining this she told us about her research. In the lab, she extracted the plastics from the scrubs to see the amounts that would be going into the environment. About three billion beads are in one bottle of facial scrub and ten thousand beads in one squirt. Imogen's discoveries lead to the ban of microbes in many products. Three years after the ban, she went back into the lab and tested the same scrubs again, to find nothing. Her second research was on washing clothes and the amount of plastic that comes out of the fabric each time. Her lab found that in every 6 kilograms of clothes, 700,000 micro-beads are released into the sewage and end up in the ocean. Her solution to this was to wash clothes less and get more wear out of them before carelessly throwing them in the hamper. Her third lab was with products that claim to be biodegradable, she took biodegradable grocery bags and ran different tests with each. One in direct sunlight, one planted in soil, and the other in the ocean. After 3 years, she found that all of the bags were still in bag shape/form, she was even able to carry a week's worth of her own groceries in one. The bag in the sunlight degraded the most, sunlight breaker up plastic into smaller pieces by targeting the chemical bonds. Her last main experiment was with ropes, and how as they get older, the more micro-plastics they are released. About 700 micro-plastics per meter for an old rope, and 20 per meter for a new. Her suggestion for this was to keep ropes out of the sun and replace them when they start to fray. As well as all of these experiments, she was able to partner up with National Geographic and study snow from Mount Everest. Within every letter of snow from just below the peak, there are 17 micro-plastics, proving that even in the most remote natural places, human-made problems are viewed. One of the last things she told us was that she and her team found that 3 billion micro-plastics enter the ocean every day, and how the smallest changes in everyday life make huge differences in the long run.
I enjoyed this video chat maybe the most so far. Single-use plastics are something I am very passionate about and have been doing my part to reduce. I did a presentation last year on the Earth Day Committee about easy eco-friendly swaps to do in your home and now I am turning ocean pollution into my passion project and teaching younger students how to protect Mother Earth. I learned so much I didn't already know and more about things I did. My favorite new knowledge is really what plastic is made out of and the interactions between the environment and vice versa, like the sun and how the rays can break up plastic. I also really liked how we were able to test what we had just learned in a Kahoot! I wanted to ask a couple of questions: What is Imogen doing, beyond what she had already told us, to reduce her amount of waste and micro-plastics? Also when a large plastic is broken down by the sun does the plastic eventually become micro-plastic/can only biodegradable plastics be broken down by the sun?
Durand, Brent. We May Have Missed Half the Microplastics in the Ocean Https://Www.newscientist.com/Article/2243731-We-May-Have-Missed-Half-the-Microplastics-in-the-Ocean/#ixzz77gofaUbs, Getty Images, 15 May 2020, www.newscientist.com/article/2243731-we-may-have-missed-half-the-microplastics-in-the-ocean/.
Today I was a part of a virtual meeting on nature as medicine with Dr. Lem. Dr. Lem showed concrete data to support findings that nature helped improve human quality of life.
This claim was based on two theories as to why nature improves human life. 1) Humans have evolved to understand that nature keeps them alive, 2) nature is vastly different from the problem solving urban world today, making nature a form of escape. Both these claims have value as research shows that people who spend 20-30 minutes in nature had a significant cortisol drop. And those who are in nature tend to have higher self-esteem, overall happier moods, reduce depression and anxiety, and improve satisfaction with life.
Orcas Island 2021
My favorite topic covered was unconventional nature. When Dr. Lem was going through the health benefits of conventional nature, like stress decrease and reduction of depression and anxiety, I found myself reflecting on how my horse Quest brought me those same benefits. Yet when I think of conventional nature, I picture a big forest with fungi and foggy air, not a horse in its pen surrounded by dead California grass.
But when Dr. Lem talked about how you can experience nature through yourself, posters of nature, sounds of nature, and animals. I realized that Quest is just as much a part of nature as the woods are. Quest is made of natural molecules; Quest eats, drinks, and breathes using what our world has to offer, just like other natural organisms do. Quest brings me emotional peace; he and other forms of nature both don’t have a schedule or agenda for the day. Quest slows me down; I become in the moment for the beautiful four-legged natural organism standing next to me presence alone let's all the human inorganic mess to fall away.
My Curious Questions
I have questions specifically catering to people like my parents who work typical office jobs
How do the fluorescent lights business people are under all day affect their health?
How can businesses make more natural working conditions for those stuck in cubicles all day?
Water is an important resource in the world because all life needs water to exist. Many use water for agriculture, households, and recreation, but water is often taken for granted. In the documentary FLOW, the importance and uses of water are shown around different parts of the world. The filmmaker's goal is to stress the importance of water and the issues about water.
One of the documentary main topics was the water right. We spend over $30 billion on safe drinking water for the entire planet, yet many places don’t have access to clean water. Water privatization is another major issue, an example being Nestle which produces water bottles, goes into Michigan, and pumps 450 gallons of water per minute. They take in Michigan’s water for free and sell this water for profit. Their water bottles have gone under fire for using large amounts of plastic and mislabeling water saying their water is safer than tap water.
What surprises me from this film is the number of places that don’t have access to clean water. The lack of clean water leads to death through dehydration and waterborne diseases. Learning how waterborne diseases can affect a population shocked me, such as in Bolivia where one in ten children die before the age of five. The concept of clean water is overlooked in society and this concept must be talked about more because everyone has the right to clean water to survive. A new insight I got from this film is over the concept of bottled water. I have always been under the assumption that bottled water is safer to drink than tap water. Watching this film and learning that no one actually knows what’s in bottled water, makes me realize that bottled water is a hoax.
In the past 13 years since the documentary, large bottled water companies have made positive changes and given back to their community. Nestle has made changes to put their Michigan community first by donating water to Central Michigan to first responders and residents in need and Nestle has made steps to care for the environment by working to reduce trash and making their bottles 100% recyclable. In Flint, Michigan, infrastructure upgrades have been made to ensure safe water and the Clean Water Trust Fund has repaired infrastructures in areas where there is limited water, along with improving sanitation facilities in America. Rainwater harvesting systems are being used to collect and store rainwater and drip irrigation systems are being used for agriculture and other plants which helps to conserve water. There are still billions living without sanitary water or basic drinking water services, so we must use our voice to make a change because water is a right for all living things.
After learning about viruses in Season Two in my biology class, each of my team members had to brainstorm a curious driving question to create a video project, discussing our findings. With a lot of talk about whether or not people want to get the COVID vaccine, I realized that I could research the history of old epidemics, in the United States, and use that research to persuade why vaccination is so beneficial to fighting a virus. I mostly researched polio, a little about measles, but found that vaccination was the reason why cases of polio were reducing and why continents were being deemed polio-free. Thanks to herd immunity, all members of our community can be protected from a viral outbreak, helping eradicate a virus.
Want to know about herd immunity and how the history of the polio epidemic proves how vaccination is successful in eradicating a virus? Watch my video!
Overall, I am very happy with the result of the video and I loved learning about the polio epidemic. It happened before my time so I never really understood how feared the virus was or how serious the epidemic was in the United States; after COVID-19, I had always assumed the polio epidemic was similar. During the process of making the video, I definitely wanted to write ten minutes more of information than I ended up including, but it was trimmed down enough to where you get the main picture with a lot of information, but it is not too distracting with how much information there is. That leads me to my first improvement: talking slower. Since I wanted to include a ton of information, I was about 2 seconds under the 5-minute limit, so I was speaking extremely fast to make the video under that amount. I realize that I did not really breathe while talking, so for next time I can space out my wording and talk slower. I also saw a lot of my teammates were suggesting I should add some background music and I also think that would be a great idea. I originally did not add music because I thought my voice was already loud enough, and I worried it would be a little distracting. Lastly, I loved this project! I rarely get to fuel my own interests into my learning, and what I think made this project so fun was that I chose to learn about it, and obviously I got a little excited and carried away with the research aspect but I enjoyed learning! Most of all, though, I am very proud of the end result, and I hope you like it too, and that it encourages you to get vaccinated!
Blume, Staurt, and Ingrid Geesink. “A Brief History of Polio Vaccines.” Science, American Association for the Advancement of Science, 2 June 2000, http://www.science.org/doi/10.1126/science.288.5471.1593. Accessed 24 Sept. 2021.
“The World Health Organization Declares Africa Polio-Free.” Time Magazine, Time USA, 25 Aug. 2020, time.com/5883233/africa-declared-polio-free/?utm_source=newsletter&utm_medium=email&utm_campaign=the-brief&utm_content=20200826&et_rid=31820120. Accessed 24 Sept. 2021.
“Measles Cases and Outbreaks.” Center for Disease Control and Prevention, U.S. Department of Health and Human Services, 13 Sept. 2021, http://www.cdc.gov/measles/cases-outbreaks.html. Accessed 24 Sept. 2021.
“Our Progress against Polio.” Center for Disease Control and Prevention, U.S. Department of Health and Human Services, http://www.cdc.gov/polio/progress/index.htm. Accessed 24 Sept. 2021.
“Whatever Happened to Polio?” National Museum of American History, Smithsonian, amhistory.si.edu/polio/americanepi/communities.htm. Accessed 24 Sept. 2021.”What Is Polio?” Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, http://www.cdc.gov/polio/what-is-polio/index.htm. Accessed 24 Sept. 2021.
Tobacco Mosaic Virus was the first virus discovered and cause a production loss of tobacco of up to two percent.
Tobacco mosaic virus is usually spread from plant to plant via ‘mechanical’ wounds caused by contaminated hands, clothing, or tools such as pruning shears and hoes. This is because TMV occurs in very high concentrations in most plant cells. When plants are handled, the tiny leaf hairs and some outer cells are inevitably damaged and leak sap onto hands, tools, and clothing. Seeds from infected plants can also carry the virus on their seed coats.
Once inside the plant, the virus releases its genetic code (RNA). The plant mistakes this for its own RNA and starts to produce viral proteins.
The virus then spreads to neighboring cells through microscopic channels in the cell walls (plasmodesmata), and eventually enters the translocation system of the plant (xylem and phloem). From here, it spreads to the entire plant.
Improvements
Before receiving feedback from my classmates, the infographic was a bit different. What didn't work was the organization of the space, because the number of words was perfect but there were too many pictures on the top and none in the other parts of the slide. For this reason, it was not balanced, and what my teammate and I did was add visuals connected to the topic of each paragraph; for example in the paragraph about the origins of the TMV, we put a map that shows in what part of the world the virus started spreading. We also edited the scripts' colors and we changed the Infection visual. Now I believe that our graphic is much more organized and interesting!
This week in AP Bio we had the opportunity to do a fetal pig dissection! Dissections have always been my favorite part of science classes because it's a chance to see up-close what our organs look like.
We first started by determining the gender of the pig and ours turned out to be a male pig. Next, we measured the length of the pig to get a rough idea of how old our pig was. He was a little over 30cm long, which means he was very close to birth time already.
Then, we moved onto the abdominal cavity which was so interesting to learn more about. I think the best part about dissections is that it's a great opportunity to try and apply what I've learned in class to real life. While textbooks and online images use different colors to differentiate organs, the organs of this fetal pig were all the same color. At first glance, it's easy to mix up the small intestine and large intestine because of their similar structure/appearance but once I looked closer I remembered the ways to differentiate them and I realized just how much I've been learning in this class!
Here's an image from our dissection worksheets! How many can you label?
We learned more about the function of each organ and how they all play an important role in how our body functions. The diaphragm separates the thoracic and abdominal cavities and aids breathing, the pancreas makes insulin, and our gallbladder stores bile. I also found the mesentery organ really interesting because I've always wondered what holds our intestines and other organs in place while we move about through our day.
Looking through the thoracic cavity was super interesting as well because it gave me an idea of how my own thoracic cavity looks like. The size difference in the lungs was fascinating to look at because textbook diagrams don't usually show the difference. Our left lung is usually smaller than the right lung because our heart is closer to the left side of our chest, so it slightly rests on the left lung. We also took a closer look at the inside of the pig's heart and I loved seeing the different components of a heart.
Another image from our dissection worksheets! How many can you label?
Overall, I had so much fun watching this dissection. It was so fascinating and a great learning experience. I hope in college I have the opportunity to do more dissections, maybe even on a different animal!
This week in my AP Biology class, we had the opportunity to participate in a fetal pig dissection to explore the Kingdom Animalia. In previous classes and camps, I have dissected a frog, worm, squid, and fish... but this so far was the most interesting!
Edu, byTeam Leverage, et al. “18 Interesting Science Experiments for Class 6 at Home.” Leverage Edu, 14 Mar. 2021, leverageedu.com/blog/science-experiments-for-class-6/.
Due to Covid-19, the amount of hands-on labs we have completed this year has been minimal. So, when given the opportunity, my class was excited to watch our teacher dissect a fetal pig and teach us about the different structures in our body! What I found interesting about this lab was getting to see how the organs and tissues package together and fit within an organism. It was fascinating to discuss the different structures and functions of each organ and relate this to the human body and previous topics in AP bio. Our class was able to make connections to previous units that covered the topics of cell structure, diffusion, osmosis, enzymes, and evolution. As our teacher completed the dissection, we eagerly discussed how these topics related to the many processes that occur in our body!
Vectorwin, et al. “Probiotic Icon Vector. Isolated Contour Symbol Illustration Stock Vector Art 1213467627.” IStock, www.istockphoto.com/search/2/image?mediatype=illustration&phrase=small+intestine.
For example, when exploring the coiling small intestine, we noted how large the surface area to volume ratio was. Then, we connected this back to our topic of osmosis and diffusion, discussing how a large surface area to volume ratio allows water and important nutrients to diffuse at faster rate - because there is more surface area (room) for these molecules to diffuse through. This is beneficial to the organisms because the organ will get the important water and nutrients it needs for the cells to function properly.
This investigation left me curious about about my own body and the many processes happening in these complex systems! Overall, I really enjoyed being able to participate in a hands-on lab that explored Kingdom Animalia. Fascinating!
Check out this short video on how to dissect a fetal pig! Note - content may be disturbing to some viewers:
Protista is more or less the catch-all phylum of the life classifications. Anything that cannot be classified as plant, animal, or fungi is placed here. This results in an extremely diverse, and truly captivating group of organisms. One of the most common protists are seaweeds. My team and I explored different seaweeds, and various other types of protists for this lab, to get a better idea of what truly makes up this mosh pit of life.
Ever since she was a child she has been very in tune with the environment, as she lived in a home with a three hundred year old oak tree growing through the porch. This unusual feature of her home. sparked her interest in the environment and science. Since she has moved on from her home in Ithaca, New York she has been involved in work surrounding how people interact with the world around them.
Carrère has had access to so many amazing travel opportunities through her work with National Geographic. For example she has done work in Madagascar, the Falkland Islands, Bangladesh, and the Philippines. In Madagascar she studied how farmers dealt with deforestation. She found that farmers had adapted to their new landscape by creating holes to move water down hillsides and control the irrigation of their crops.
National Geographic has granted Carrère the opportunity to host a series called Modern Explorer where alongside co-host, Tom Richie, Carrère looks into what makes an explorer. Her visit to the Falkland Islands and South Georgia consisted of studying fur seals and king penguins among others. She mentioned that she chose Richie as her co-host because he has a lot of experience traveling for scientific research. As he is an older scientist, he brings a different perspective of travel and methods of conducting research. Carrère explains that he bridges a different generation of explorers. In the first episode of Modern Explorer, Carrère notes the differences between her and Richie’s form of documenting their findings. Carrère’s method consists of many pictures and journal entries while Richie has shelves and drawers of his findings in a shack by his house. The two forms of documenting shows how much technology has affected our world and the way we keep track of information.
Today in AP Biology, our class watched a NOVA documentary about how epigenetics affects gene expression. When the entire human genome was mapped, scientists were surprised that there were only about 25,000 genes, the same as fish or mice. This was not expected because humans are more complex than organisms such as fruit flies. Scientists began to wonder what else may contribute to human complexity other than genes, mainly epigenetics.
What is the epigenome? Epigenetics translates to “above the genome”. The epigenome consists of histamine proteins that wrap around the DNA which provide structure. These proteins can either activate or turn off certain genes. When proteins “hug” the DNA tightly, then it is hidden from view for the cell, and cannot be expressed. Environmental factors such as diet and stress can impact the structure of the epigenome which affects how the genetic code is read and expressed.
The movie illustrated this concept with an example of how identical twin mice can weigh differently depending on the activation or deactivation of the agouti gene. The methyl group marker turned off the agouti gene in the thin mice. Scientists were able to control the offspring of the fat agouti mice by silencing the agouti gene in the mother with certain minerals. The change in her genome passed to her offspring resulting in thin baby mice.
To further understand the impact of epigenetics, the film discussed some studies done on identical twins. Because identical twins have identical genomes, any differences between the twins can be traced to the impact of epigenetics. Scientists can determine exactly how these chemical markers can affect the expression of genes. In a study, the researchers used DNA from identical twins and compared gene expression. The scientists observed how the epigenome in twins differentiates over time from outside experience. Although twins may have the same DNA, their epigenome can become completely unique.
The film showed another study done with rats. Scientists concluded that environmental factors can change the expression of DNA within a lifetime and pass down those changes to following generations. The researchers observed two groups of rats, one with nurturing mothers and the other with detached mothers. The offspring of these two groups significantly responded to stress differently. This was not from genetic differences but their environmental experiences. When studying the epigenomes, they discovered discrepancies in the markers on genes that affected stress response.
The movie went on to discuss how environmental factors can lead to human disease. When epigenetic changes silence tumor suppressor genes or active oncogenes, the regulation of the cell cycle can be affected. This can result in overstimulation of cell division or an inability to inhibit cell growth leading to tumors or cancer. Doctors have started doing epigenetic therapy for diseases such as cancer. Medical professionals can now treat patients with drugs that remove silencing tags that turn off the tumor suppressor genes. Over half of these patients have experienced significant remission in their cancer growth with minimal side effects. One example patient explained how he has now been cancer-free for two years after receiving this epigenetic treatment.
The speaker went on to describe how epigenetics can help explain why a specific gene for autism has yet to be found. Because the epigenome can affect the expression of any gene, it is difficult to identify a specific sequence that was chemically tagged to turn on or off. Additionally, for each individual, the markers may affect DNA differently. The film showed a set of identical twins where one sister had autism while the other did not. Since their DNA is identical, the epigenome would make the difference in their conditions.
At the end of the movie, the episode focused on the information found in a Swedish village that helps to explain more about epigenetics and inheritance. Scientists tracked births and deaths for centuries alongside the frequent famines that occurred. The researchers were initially looking at the connection between poor nutrition and health. During the study, they discovered that the available food supply from one generation affected the grandchildren with an increased or decreased risk for diabetes. This was not from direct mutations to DNA but the environmental information tagged on the epigenome.
After watching this documentary, I was surprised by the complexity that epigenetics adds to gene expression and our understanding of human DNA. I am excited to see how this science will develop in the future especially with improvements for medical treatments. The conclusions made from the Swedish village made me rethink the choices I make today knowing they can affect my children or grandchildren later on. Learning about this "second genome" provided insight into how experiences can mold genomes within a lifetime and live in following generations.
