BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: biology (Page 1 of 6)

Unlock the POV of Pups: How Dogs See the World Beyond Colors.

Madsen the dog, 001

Have you ever wondered how your furry friends recognize the world around them? This question was asked by a group of scientists who recently studied how canines “see” the world not only with their eyes, but also with their nose.

For a long time, the world believed that dogs could only see the world in black and white, or that dogs could only perceive color weakly, if at all. However, this myth was debunked in 1989 by ophthalmologist Jay Neitz and his colleagues, who discovered that dogs can indeed see colors, specifically blues and yellows. They cannot perceive reds and greens, similar to color-blind human.
Assorted Red and Green Apples (deuteranope view)

The reason why dogs can’t process light as well as most human is because they only have two types of color-sensing receptors, called cones, in their retinas, similar to many mammals: cats, pigs, and raccoons. This differentiates them from humans which have three cones. In addition, most dogs have 20/75 vision, meaning that they need to be 2o feet away to see as clear as a human would from 75 feet. Their world may be somewhat blurry compared to ours.

To truly understand how dogs see the world, we must look beyond their ability to process color, as highlighted by Sarah-Elizabeth Byosiere. Dogs rely on various other senses to help them “see,” or identify objects and movements around them. For example, unlike humans who have difficulty seeing in dark environments, dogs’ eyes are made to see in both daytime and nighttime. This is because of their abundance of rods, a type of photoreceptor cell in the retinas, which aids in night vision. Rods are 500-1000 times more sensitive to light than cones which allows dogs to see better in the dark. Dogs also have a unique structure in their eyes called the Tapetum Lucidum(Shown in diagram below), which acts like a mirror that reflects light back onto the retina. This enables them to see in conditions with six times less light than what human requires to see.

This is also the reason why dogs’ eyes will glow in photos in the dark, because their Tapetum Lucidum reflects the light back.

(Structure of eyes)

Mammal eye structure (tapetum lucidum)

Another significant aspect of dogs’ perception is their sense of smell, they are 10,000 to 100,000 times stronger than that of an average human. Dog’s mighty sense of smell plays a crucial role in how they perceive the world, they can even pick up odors from as far as 12 miles. Another study published recently in the Journal of Neuroscience revealed a direct connection between dogs’ olfactory bulb, which processes smell, and their occipital lobe, which processes vision. This integration of sight and smell was not observed to happen on any of other animal species.

While human are good at recognizing different colors, dogs are more into their sense of smell that humans can’t appreciate. Dogs aren’t missing out on anything; they just have their own unique way of exploring the world around them.

In AP Biology, we learned about how neurons transmit signal to the brain when we touch, hear, see, and smell. When vision and smell is received by optic nerve in eyes and olfactory sensory neurons in noses, they will pass the information of the sight and smell to the brain through neurons. Neurons transmit signals simply through a flow of ions across the axon membrane, which reverses the distribution of charges of the neuron compared to when it is at rest. This is how a neuron passes a signal to another neuron, they will repeat this process until they reach the occipital lobe and olfactory bulb in the brain where the information of the sight and smell will be processed and analyzed.

As a biology student, I have always wondered about how canines, mankind’s best friend, and how other animals see the world in their perspective. It is fascinating to find out that all animals have their unique way of sensing the world and collecting information from the area around them. Their “sensing” strategy are often different from ours’s; human primarily uses vision to receive information of the world, but our neighbors on earth could be using their sense of smell, sense of hearing, and even echoing to accomplish the same goal! Let me know in the comments below if you are also curious about how other animals recognize our world or if you are interested in this topic! Share your thoughts with me! If you want further information about this post or on this topic in general, please go to ScientificAmerican.com for more information and further research.

A New Approach to Wound Care

Researchers at Linköping University in Sweden have made an incredible contribution to the field of medicine, specifically in wound care and infection detection that does not interfere with the patient’s healing process.

In medicine, wounds are typically treated with a dressing, which is changed often to avoid infection. In order to detect infection, healthcare providers have to frequently open the wound’s covering, which can be painful and can potentially disrupt the healing process. Additionally, each time the wound is opened, the risk of infection is increased. The researchers were alarmed by this issue, and developed a wound dressing comprised of nanocellulose that has the ability to display early signs of infection without further tampering with the wound or lifting the dressing. Daniel Aili, a professor involved in the study, has confidently stated that “being able to see instantly whether a wound has become infected, without having to lift the dressing, opens up for a new type of wound care that can lead to more efficient care and improve life for patients with hard-to-heal wounds. It can also reduce unnecessary use of antibiotics.”

The new wound dressing is made of a tight mesh nanocellulose material, which prevents bacteria and other harmful microbes from entering the wound. However, the mesh-like material allows airflow in, which is critical in the wound healing process. However, if the wound does become infected, the nanocellulose dressing will display a shift in color, notifying healthcare providers that the wound needs care. pH also plays a major role in this creation. Wounds that are not infected maintain a pH value of about 5.5. If an infection occurs, the wound starts to become basic and can increase to a pH value of 8, or higher. The increase in pH occurs because the wound’s bacteria shift their pH to properly fit their optimal growth environment. As we learned in AP Biology class, bacteria and enzymes have an optimal pH level to grow and function. If this level is not maintained, they cannot function properly. So, the bacteria increase their pH in response to infection if the optimal level is compromised. This elevated pH level in the wound can be detected by the nanocellulose dressing before any physical signs of infection.

pH Value Scale

In order to make the nanocellulose display infection with an elevated pH value, the researchers used bromthymol blue, a dye that reacts to a change in pH value. The bromthymol blue shifts from yellow to blue if the pH value increases past 7. The material of the bromthymol was then able to be combined with the dressing material without ruining the nanocellulose. As a result, the researchers successfully developed a safe-to-use, noninvasive wound dressing that will display a blue color if an infection occurs.

Bromothymol blue colors at different pH levels

 

Have you ever been caught with a viral disease and been misdiagnosed by your doctor? New CRISPR technology may eliminate this from happening.

So first, what even are viral diseases and how can they affect your health?  Well, some common viral diseases include HIV, herpesvirus, COVID-19, or even the common cold. Any disease classified under viral can enter your body through breathing air, touching something with viruses on it, intercourse, close contact, or getting bitten by a bug “such as a mosquito or tick”. Viruses typically infect one type of cell in your body and this is why the “common cold typically infects only cells in your nose, mouth, and throat”

In a study by PubMed Central (PMC) their goal was to identify the most common errors in diagnosing infectious diseases and their causes using physicians’ reports. In their concluding results, “the most common infectious diseases affected by diagnostic errors were upper respiratory tract infections (URTIs) (n = 69, 14.8%), tuberculosis (TB) (n = 66, 14.1%), pleuro-pulmonary infections (n = 54, 11.6%)”. This data was taken from a sample of 465 patient cases and the researchers concluded that, “a substantial proportion of errors in diagnosing infectious diseases moderately or seriously affect patients’ outcomes”. So when diagnosing viral infectious diseases, steps need to be taken to improve our testing process.

Researchers from the American Chemical Society are looking at using “glow in the dark” proteins to help diagnose viral diseases. Fireflies, anglerfish, and phytoplankton all create a glowing effect using bioluminescence, which is caused by a chemical reaction involving luciferase protein. This protein has been used in sensors for point-of-care testing, but lacks the high sensitivity needed for clinical diagnostic tests. Researchers wanted to combine CRISPR-related proteins with a bioluminescence technique to improve sensitivity. They developed a new technique called LUNAS, which uses recombinase polymerase amplification (RPA) to amplify RNA or DNA samples. Two CRISPR/Cas9 proteins bind to targeted nucleic acid sequences and form the complete luciferase protein, causing blue light to shine in the presence of a chemical substrate. This new technique successfully detected SARS-CoV-2 RNA in clinical samples within “20 minutes, even at low concentrations“. The researchers believe this technique could be used to detect many other viruses effectively and easily.

In relation to AP Biology, we have learned about the process of gene expression where RNA and proteins are produced due to a specific gene being activated. The regulation of gene expression conserves energy and allows organisms to turn on and off genes only when they are required. The CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) gene which are found in prokaryotes cut DNA phages and plasmids to prevent damage to the prokaryote itself. It is used as a rudimentary immune response system. The CRISPR can be associated with other proteins to create an associated complex which allows for the excision and insertion of genes along the length of the genome. Using this process, viral diseases can be identified when combined with the bioluminescence mentioned above.

Looking into the future, researchers are searching for ways to apply CRISPR proteins to detect a greater range of viral diseases so that all patients can get the proper care that they need.

 Cancer Detection Using CRISPR Gene Editing

Currently, many are accustomed to invasive cancer diagnostic methods such as endoscopies, colonoscopies, and mammograms. Driven by the desire to discover new methods, a group of researchers from the American Cancer Society developed an alternative method, which is a significant contribution to cancer detection.

Utilizing CRISPR gene editing as their approach, the group of ACS researchers developed an easy-to-use mechanism for detecting small amounts of cancer in plasma. CRISPR gene editing is a method that scientists and researchers have been using to modify an organism’s DNA. CRISPR gene editing is often done for numerous reasons, such as adding or removing genetic material, creating immune defense systems, and repairing DNA. Their detection method also allows healthcare professionals in diagnostics to decipher between malignant and benign cancer-related molecules that they may discover.

CRISPR Gene-Editing

The first step that the researchers made to develop this approach was to design a CRISPR system that creates a manufactured exosome out of two reporter molecule fragments, which they cut. An exosome is a small vesicle that carries material such as lipids, proteins, and nucleic acids after branching out from a host cell. Exosomes are typically involved in detecting cancerous cells because they provide a glimpse into the host cell they branched out from. Therefore, cancerous cells are shown in their exosomes through biomarkers, like micro RNAs (miRNA). In AP Biology class, microRNAs are described as materials that bind to complementary mRNAs to prevent the translation from occurring. MiRNAs are a recent discovery, identified in 1993. It is now concluded that most gene expression is influenced by them, so the researchers made efficient use of miRNA in their experiment. The two fragments of the reporter molecule came together and interacted with the CRISPR’s materials.

Micro RNA Sequence

The researchers concluded that if the targeted miRNA sequence was evident in the combination, the CRISPR system they made would become activated and cut apart the reporter molecule. The researchers specifically targeted miRNA-21, which is often involved in cancer development. The researchers were able to detect miRNA within a combination of similar sequences and later tested their method on a group of healthy exosomes and cancerous exosomes. Their CRISPR system successfully differentiated between the healthy and cancerous exosomes, which makes this system effective for cancer detection. The researchers are confident that their CRISPR gene editing approach to cancer detection will make diagnosis easier on patients and a more efficient process overall.

 

Back from the dead? Tech Startup attempts to bring back the Dodo bird.

Perhaps the most widely known animal extinction is the famous Dodo Bird.  According to Brittanica, the dodo became extinct after European settlers disrupted its native Mauritius.  Extinction, as defined by National Geographic, is “the complete disappearance of a species from Earth.”  However, as reported by US News, new technological innovations hope to reverse extinction and bring back the dodo bird.

According to the article, a tech startup Colossal Biosciences hopes to use gene editing technology to bring back extinct species, such as the dodo bird.  According to MedlinePlus, “genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism’s DNA.”  According to Beth Shapiro, A biologist at the company stated that the company intends to edit the genes of the non-extinct Nicobar Pigeon, a close relative of the dodo, to recreate the dodo, hundreds of years after its extinction.  

Dodo 1

Despite these promising advancements, because researchers intend to use the genes of a different species, and the conditions on the island are not the same as they are today, it will be nearly impossible to revive the dodo bird exactly.  For example, as reported by US News, Shapiro stated “it’s not possible to recreate a 100% identical copy of something that’s gone.”  

While these advancements are exciting, as US News stated, there could be significant drawbacks to bringing back extinct speeches.  As stated by ecologist Stuart Pimm of Duke University “There’s a real hazard in saying that if we destroy nature, we can just put it back together again – because we can’t.”  As stated earlier, it was colonists and mistreatment of the environment that caused the extinction of the dodo bird in the 1600s, so perhaps, as reported by US News and stated by Boris Worm of the Univerity  of Dahlhousie in Halifax, Nova Scotia “Preventing species from going extinct in the first place should be our priority.”  Perhaps we can achieve this goal by taking better care of the environment, for according to Columbia Climate School, “The main modern causes of extinction are the loss and degradation of habitat (mainly deforestation), over exploitation, (hunting, overfishing), invasive species, climate change, and nitrogen pollution.  Many of these ideas connect to what we have studied in biology class, such as the effects of genes.  According to Brittanica, Gene editing technology uses enzymes to influence genetic sequences; these enzymes are called Restriction Enzymes.  Additionally, according to the University of Illinois, “Restriction enzymes are essential tools for recombinant DNA technology.”  As we learned in the Mitosis/Meiosis, and cellular respiration unit, recombinants are the chromosomes that occur when chromosomes “cross over” during Prophase I of meiosis, essentially creating a blend of different traits.  This phenomenon is similar to what occurs in gene editing technology, where enzymes snip DNA, adding different traits, to create a sort of “mix” of traits.

 Therefore, while these new technologies in gene editing are exciting, we shouldn’t be 100% convinced of their effectiveness, and we should continuously question the ethics of such practices.

How Baby Kangaroos Are Helping Climate Change

In the world, there are over 1 billion cows and calves, roughly 4.3 times as many cows as people living in the United States. Cows are the number one source of greenhouse gases worldwide, with a single cow producing 220 pounds of methane gas a year. Methane (CH4) is a colorless, odorless, and highly flammable gas, composed of carbon and hydrogen. Being a potent greenhouse gas, it impacts climate change by increasing global warming according to the US Environmental Protection Agency. Methane affects our environment but it can also impact humans “high levels of methane can reduce the amount of oxygen breathed from the air. This can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing, and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness“. Although this is in extreme cases. Recently, scientists may have discovered a methane inhibitor that could reduce the amount of methane cows release. This source comes from an interesting source though: Baby kangaroo feces.

 

It's a cowspiracy ! - Wake up and smell the methane. (23335965671)

 

Researchers from Washington State University wanted to figure out a solution to lower methane gas production rates in cows seeing as people enjoy eating red meat and taking them entirely out of the equation is not a feasible answer. They performed a study using baby kangaroo fecal matter to develop a microbial culture that inhibited methane production in a cow’s stomach stimulator. This resulted in cows producing acetic acid – is also known as ethanoic acid, ethylic acid, vinegar acid, and methane carboxylic acid; it has the chemical formula of CH3COOH. Acetic acid is a byproduct of fermentation and gives vinegar its characteristic odor. Vinegar is about 4-6% acetic acid in water – in place of methane. Acetic acid is not just a waste product in a cow like methane but is actually beneficial for the cow as it helps muscle growth. Not only would lowering rates of methane production in cows be beneficial for the environment but also for the cow as the cow wastes around 10% of its energy in methane production. Researchers have tried chemical inhibitors but the methane-producing bacteria has become resistant each time. The actual experiment all began with the researcher’s study of fermentation and anaerobic processes, which lead to the creation of an artificial lumen designed to stimulate cow digestion. Then they began investigating how they could outcompete the methane-producing bacteria and learned that – specifically – baby kangaroos have acetic acid-producing bacteria instead of methane-producing bacteria. Researchers were “unable to separate out specific bacteria that might be producing the acetic acid, the researchers used a stable mixed culture developed from the feces of the baby kangaroo.” Eventually, the acetic acid bacteria was able to replace the methane-producing microbes for several months having similar growth rates. Researchers hope to eventually test their system outside of a stimulated rumen and on a real cow sometime in the future. This connects to our unit of enzymes and enzyme inhibitors. Enzymes allow the cell to perform tasks with less energy by binding to reactant molecules and holding them in a way that breaks the chemical bond allowing bond-forming processes to take place more easily. Enzyme inhibitors are molecules that bind to the active site – competitive inhibition – or the allosteric site – noncompetitive inhibition – making the enzyme unbindable, reducing the rate of enzyme-catalyzed reaction, or preventing it from happening altogether. This is what the researchers are trying to do in their study, inhibit the enzyme in the methane-producing bacteria and allow the acetic acid bacteria to grow instead. Overall, if this process proves to work in real cows it could be a huge advancement in the slowing down of climate change.

 

 

 

 

Self-Assembling Hydrophobic Sandwiches

You read that correctly! Researchers at Rice University in Houston, Texas alongside Jeffrey Hartgerink have made a significant advance in injury treatment, illness education, and drug candidate by testing the self-assembling abilities of 3D printed nanofibrous multidomain peptide hydrogels, referred to as “hydrophobic sandwiches.” 

Hydrogel

The main goal of Hartgerink’s team was to create a structure that could house cells and help them grow tissue by 3D printing the peptide ink. The printing allows researchers to recreate the complexity of biological structures due to their soft and flexible tissue-like feel, making this a major scientifical discovery and advantage. Hartgerink and his team describe their printed peptides as “hydrophobic sandwiches” due to their design, flexibility, and behavior. The peptides were printed to have one hydrophobic side and one hydrophilic side, allowing them to flip on top of each other when placed in water and resemble sandwiches. Like we learned in AP Biology, the hydrophillic qualities of one side will attract water, and the hydrophobic qualities of the other will repel water. Hydrophobic molecules repel water because they are nonpolar molecules, so they are not attracted to water, which is polar. Once the “sandwiches” were stacked after flipping in the water, they formed the hydrogels which can be vital to tissue engineering and wastewater treatments. 

Hydrogel Structure

The multidomain peptides have already been utilized due to their self-assembling nature for regenerating nerves, treating cancer, healing wounds, and encouraging tissue development throughout the body. Rather than only focusing on this aspect of the peptides, Adam Farsheed, a lead author in Hartgerink’s study, wanted to specifically highlight the fact that these peptides are an ideal 3D-printing ink choice due to their self-assembling nature. When testing the “sandwiches,” Farsheed took a unique, brute-force approach to add more of the material, rather than chemically modifying it, to test its function and ability to reassemble itself after deformation. He proved that adding more peptide material lets the peptide reassemble and heal itself extremely well after being deformed. This discovery will make the hydrogels an ideal candidate for scientific and medical usage.  

Through continued testing, he was also able to confirm that the peptides behave differently depending on their charge. The peptide cells with a negative charge tended to ball up on the substrate of the experiment and the positively charged cells spread out and started to mature on their own. Farsheed has confidently stated that their findings will allow the group to “control cell behavior using both structural and chemical complexity.” Both Hartgerink and Farsheed have made incredible contributions to the world of science through their studies using 3D-printed peptide hydrogels. 

 

A View into Life Millions of Years Ago

In an obscure geological valley at the very northern tip of Greenland’s large ice sheet, investigators have uncovered scientifically derived evidence of the existence of a lush, ancient ecosystem that was functioning over 2 million years ago. The clues to this ecosystem come from the oldest DNA ever recovered, bits and pieces of genetic material, carefully and tediously extracted from buried sediments representing more than 100 kinds of animals and plants. The investigators painstakingly extracted and “sequenced” the DNA strands and compared them to libraries of existing DNA “reads” from living species today.

DNA double helix horizontal
This is an incredibly impressive example of the power of environmental DNA (eDNA), as it is genetic material collected from the ambient environment and not individual organisms. The investigative team aimed to collect hundreds of samples from different locations within the ancient valley and reconstruct what this ecosystem looked like before the ice age. They found many different types of conifers, including poplars, thujas, and species like black geese and horseshoe crabs, that are now common further south of Greenland, but most of which are no longer found in the Arctic at all.
There are many reasons that I believe this discovery is important, not the least of which is that it may give scientists clues as to how some species were able to adapt to climate change in the past and give us some insight into climate change and evolution as we advance. It may also turn the time-honored discipline of paleontology on its head by driving it from its almost all fieldwork mode into the molecular biology laboratory.

The DNA/RNA biochemical process plays a very important role within the nucleus of each cell which defines the existence and evolutionary success of living plants and animals on the planet. The article which I selected from “Nature” discussed above, really emphasizes importance of these chemical structures regardless of whether we are investigating the past, looking into possible future biological scenarios, or looking to “improve”, correct or modify existing biological systems. Understanding both the future and historic past of the biology of the planet is no longer simply relegated to the desktop microscope, but more appropriately is a function of understanding the complex biochemical reactions at the molecular level, not just the cellular level. The extraction of biological (environmental DNA) material from historic sediments thousands of years old underscores the important changes taking place in this exciting new field and emphasized to me that the study of DNA/RNA biochemistry is very relevant to understanding all living systems, past, present and likely into the future.

 

A new evolution in cancer metastasis research

 

Perhaps the greatest fear of any cancer patient is metastasis.  According to Cancer.Net, metastasis is the process by which cancers spread throughout the body.  Furthermore, according to Cancer.gov, “Metastatic cancer is notoriously difficult to treat, and it accounts for most cancer deaths.” However, a new study in Nature, as outlined in an article in The Scientist, unearths new truths about how cancer cells metastasize that could perhaps spark a new wave of research.  

As stated in The Scientist, “Previous studies have shown how, counterintuitively, cells pick up the pace as they move through thicker solutions.”  Recent studies have elaborated on this accepted facet of cancer reaction, and have discovered that Cancer cells have the ability to detect, and even memorize the viscosity of their environments.  Researchers noticed that cancer cells initially exposed to viscous environments retained their speedy movement even after they were moved to watery environments, at a level not represented in those constantly in watery solutions, thus indicating a sort of memory of environment in cancer cells.  This phenomenon of “cell memory” is similar to the memorization features seen in T-memory cells we discussed in class during the unit on the immune response.

Breast cancer cell (2)

Later, that same team of scientists released study that aimed to determine how cancer cells are able to move quickly through viscous substances.  According to an article in The Scientist, “cancer cells move by taking up water at the front of the cell and squirting it out the back, propelling themselves like octopuses through narrow spaces.”  Some researchers believe that new drug research could aim to target the ion channel that causes this transportation: TRPV4, but others are not so convinced.  According to Miguel Valverde of Pompeu Fabra University, “Animal knockouts for the TRPV4 channels develop normally,” indicating that the newly discovered transportation mechanism may not be as essential as researchers may believe.

Still, the discovery of a new transportation method for cancer cells explaining its peculiar preference for viscosity is an important breakthrough, that will undoubtedly guide future research in cancer metastasis. 

Are Rats Really Interacting With Reef Fish???

A new study has found that the presence of invasive rats on tropical islands is affecting the territorial behavior of fish on surrounding coral reefs. The rats, which arrived on the islands as stowaways on ships in the 1700s, change the behavior of jewel damselfish, a herbivorous species of tropical reef fish that “farm” algae in the branches of corals.Microspathodon chrysurus

The study, which was led by scientists from Lancaster University in the UK and involving researchers from Lakehead University in Canada, was published in Nature Ecology and Evolution and compared five rat-infested and five rat-free islands in a remote archipelago in the Indian Ocean. The rats disrupt an important nutrient cycle by attacking and eating small resident seabirds and their eggs, leading to a drop-off of nutrients in the seas surrounding rat-infested islands. This results in a lower nutrient content of seaweed for herbivorous fish, such as the damselfish. The damselfish around rat-infested islands behave less aggressively and need to have larger territories due to the lower nutrient content of the algae.

Seabirds travel out into the open ocean to feed and return to nest on islands. The seabirds then deposit nutrients, through their droppings, onto the islands, and many of these nutrients are subsequently washed into the seas, fertilizing the surrounding coral reef ecosystems. On islands with invasive rats, the rodent populations decimate the seabirds, leading to seabird densities that are up to 720 times smaller on rat-infested islands. This results in much less nitrogen flowing onto the coral reefs around these islands.

Seabirds LC0141

Around islands with intact seabird populations, the farming damselfish aggressively defend their small patch, typically less than half a square meter, of the reef to protect their food source – turf algae. However, the scientists observed that farming damselfish on reefs adjacent to rat-infested islands were much more likely to have larger territories and were five times more likely to behave less aggressively than those who lived on reefs adjacent to islands without rats. The damselfish around rat-infested islands need to have larger territories because the algae around rat-infested islands is less nutrient-rich due to the missing seabird-derived nutrients.

NSW seabed 1

This behavior change in the damselfish could potentially have wider implications for the spread of different species of coral, the distribution of other reef fish, and the resilience of damselfish over generations due to changes in hereditary traits. Changes in behavior are often the first response of animals to environmental change and can scale up to affect how and when species can live alongside one another. This study is the first to show that invasive rats can change the behavior of coral reef fish in this way and highlights the importance of understanding and managing the impacts of invasive species on ecosystems.

Students in our AP Biology class are likely to be familiar with these concepts of nutrient cycling and the importance of nutrients in supporting the growth and productivity of an ecosystem. The study highlights how the nutrient cycle on coral reefs is disrupted by the presence of invasive rats, leading to a drop-off in nutrients in the surrounding seas and a lower nutrient content of seaweed for herbivorous fish. This can have consequences for the growth and productivity of the coral reefs and the overall health of the ecosystem.

Try to eat just one potato chip – it probably won’t happen.

Potato Chips or any junk food for that matter can be very addicting after just the first bite. The high concentrations of carbohydrates, sugars, and fats commonly found in these processed foods contribute to one of America’s greatest health risks, adult obesity. Today, over 40% of America’s adult population is considered obese and in the last 20 years, the prevalence of severe obesity has almost doubled to 9.2%. A single bag of Lay’s Potato Chips contains 15g of carbohydrates and around 170mg of sodium which could take around 15 mins of very intense workout to burn off. We have learned in AP Bio that consuming many carbohydrates without burning them off through exercise results in carbs converting into fatty acids during cellular respiration. So, when looking into obesity, researchers from Osaka Metropolitan University wanted to understand why “High-calorie foods — high in fat, oil, and sugar” tend to be overeaten.

Walmart Wenatchee 2

The researchers investigated the specific gene behind overeating and linked it to one named “CREB-Regulated Transcription Coactivator 1 (CRTC1).” In the past, trials on mice have indicated that when the CRTC1 gene is removed, they become more obese indicating that it “suppresses obesity”. But, it is now known that CRTC1 is found in all neurons around the brain so, they wanted to dive deeper and find the specific mechanism or neuron within this gene that reduced obesity.
First, Associate Professor Shigenobu Matsumura, who lead the research, hypothesized that “CRTC1 expression in MC4R-expressing neurons suppressed obesity because mutations in the MC4R gene are known to cause obesity.” So, they conducted trials on mice, manipulating the MC4R-expressing neurons to test their theory. It turns out that when on a standard diet, the original mouse and the one with the manipulated MC4R gene remained the same weight. But, when put on a high-fat diet, or one more resembling junk food, the mouse that was deficient with the CRTC1 MC4R neuron became “significantly more obese than the control mice and developed diabetes.” Reflecting on this outcome, the researchers have concluded that the CRTC1 gene plays a role in controlling our portions. Looking forward, the researchers hope this will lead to a better understanding of what causes people to overeat.

Mouse Brain Cross-Section

In our current AP Biology unit, we have been learning about cell respiration and the way our body consumes both O2 and food to create ATP energy. Our body can break down glucose through glycolysis, convert it into two Pyruvate, and then Acetyl CoA, to then create NADH and FADH2 through the Citric Acid Cycle to produce about 28 ATP energy molecules through Oxidative Phosphorylation. Other nutrients we consume like fats and proteins are also converted to ATP energy when needed but, when no energy deficit is created through activity, these nutrients along with excess glycogen are bound to insulin to create fat around the body. Looking forward, it is important to understand how addictive these unhealthy foods can be on a neurological and biological level, warning us of the dangers of overconsumption.

Newly Discovered Neurons and Their Role in Maintaining Normal Body Temperature

The internal body temperature in humans and mammals is maintained at 37℃/96℉, unless disrupted by a force like an illness or heat exhaustion. Regulating the body to stay in the normal range is crucial for survival and for enzyme function.  Our internal body temperature is constantly being regulated by our hypothalamus, located at the base of our brain. The hypothalamus uses sensors from a mediator known as prostaglandin E which is brought about when an infection is present in the body. After PGE2 is present, it signals for the body to raise its temperature and combat the infection. If temperature levels are abnormal, the enzymes in our body have trouble functioning because they need specific temperature conditions to carry out reactions. Therefore, maintaining homeostasis throughout the body by regulating internal temperature is key to human survival.

Prostaglandin E

A team of researchers at Nagoya University in Japan were inspired by this process and decided to focus on the unknown neurons that make up the receptors of PGE2 and how this regulation process functions. The group of professors and colleagues successfully discovered key neurons that work to regulate the body temperature of mammals. This finding can be highly useful for creating future technology that can artificially fix body temperature related conditions such as hypothermia, heat stroke, and obesity.  

Neuron

Neuron

By using rats as a subject for their research, they exposed the rats to cold (4°C), room (24°C) and hot (36°C) temperatures to observe the effect of temperature changes on EP3 neuron response. After conducting the experiment, the researchers were able to conclude that exposure to the hot temperature led to an activation of EP3 neurons and the cold temperatures did not. Once they made this conclusion, they dug deeper into the neurons and analyzed the nerve fibers of the neurons to discover where the signal transmission occurs after sensing an infection. The researchers were able to conclude that the neuron fibers are spread out in different areas of the brain, mainly the dosomedial hypothalmus, which works to activate the sympathetic nervous system. Not only did they discover these fibers, but they also discovered the substance that EP3 neurons utilize to send signals to DMH. By observing the structure and chemical makeup, they found that this substance is a neurotransmitter known as gamma-aminobutyric acid (GABA), which inhibits neuron excitation. 

Finally, their findings support the idea that EP3 neurons are a major component of regulating internal body temperature and that they send out the GABA substance to signal to DMH neurons for a proper response. Their research proves that intiating a neural response decreases body temperature and inhibiting neurons leads to an increase in body temperature. Furthermore, their strong research in this area can support future development of advanced technology that will be capable of artificially adjusting internal body temperature. The anticipated technology could help prevent hypothermia, treat obesity to keep body temperature slightly higher and initiate fat burning, and be a key method of survival in hot environments. 

 

Ballerinas Got the Brains!

A 2013 research article conducted by scientists at the Imperial College of London has dived into the ballet world and researched the brains of ballerinas. Their research led to the discovery that dancers can suppress signals of dizziness using the balance organs of the inner ear. The vestibular system, found in the inner ear, consists mainly of smaller circular canals. Each canal recognizes different motions: Up and Down, Side to side, and tilting. These canals are filled with hair and liquid which move with your body to send signals to the brain using the acoustic nerve. With this information, your brain can process balance, dizziness, and vertigo. These researchers became curious about how ballet dancers can perform multiple balanced pirouettes without feelings of dizziness. And as a dancer, I would say this is because of the technique of spotting which involves rapidly moving the head to keep one’s eyes on a fixed spot.

However, this study has proved that wrong. So, with the help of 29 ballet dancers and 20 rowers, the researchers put it to the test. Their method of testing involved putting the volunteers in a dark room and spinning them on a rotating chair. They then timed how long it took for the dizziness to stop. In addition, the researchers measure eye reflexes triggered by the vestibular organs and later completed MRI scans of the patient’s brain structure. The data they collected showed that the eye reflexes and perception of spinning lasted a shorter time with the dancers than with the rowers.

From this point, doctors wondered how they could transfer this ability to their patients. After taking an in-depth look at the dancer’s brains it was concluded that the cerebral cortex and cerebellum were the most affected. The cerebral cortex is found in the largest part of the brain and is responsible for speech, judgment, thinking and reasoning, problem-solving, emotions, learning, and the senses. While the cerebellumMajor parts of the brain, a fist-sized portion found in the back of the brain, uses neurons to coordinate voluntary muscle movements and to maintain posture, balance ,and equilibrium. In the AP Biology curriculum, learning the nervous system helps in one’s understanding of transport and membranes. The nervous system sends signals across the plasma membrane of a cell to the brain. With this signal, the cerebellum and cerebral cortex can process information and signal parts of the body to move. From looking at the MRI scans, scientists discovered that the dancer’s cerebellum was smaller. Scientists believed dancers would be better off not using their vestibular system and solely relying on “highly coordinated pre-programmed movements”. Scientists believe it is not necessary for dancers to feel dizziness so, their brains adapted to suppress that feeling. As a result, the signal that goes to the cerebral cortex is reduced. So, if scientists and doctors monitor the cerebral cortex they could begin to understand how to treat patients affected by chronic dizziness.

 

 

NMT5: A New Enemy To SARS-CoV-2?

In the past few months, scientists in the United States have developed a potential new antiviral to SARS-CoV-2.   The drug, called NMT5, is effective against several variants of SARS-CoV-2, the virus that sent the planet into lockdown only a few years ago.

As stated in the journal Nature Chemical Biology, NMT5 coats SARS-CoV-2 particles as they travel through the body.  Thus, when the virus attempts to attach to the ACE2 receptor proteins of the cell, NMT5 attaches first.  The drug changes the shape of the cell’s receptor upon attachment, which makes it harder for SARS-CoV-2 to infect the cell, and on a larger scale, the organism’s body.

In order to ensure that the drug isn’t toxic, researchers tested NMT5 on healthy cells.  According to the National Institute Of Health, it was “found that NMT5 was non-toxic and only changed receptors that were being targeted by the virus. These effects lasted for only about 12 hours, meaning the receptors functioned normally before and after treatment”.  In fact, in an experiment that used hamsters as models for the human immune system, NMT5 reduced SARS-CoV-2’s ability to bond to ACE2 receptors by 95%!

A significant reason NMT5 is so effective is that it not only limits one particle of SARS-CoV-2, but the effectiveness of the virus as a whole, when present. When a SARS-CoV-2 particle with NMT5 attaches to an ACE2 receptor, it adds a nitro group to the receptor, which limits the ability of the particle to attach to the receptor for 12 hours by changing the receptor’s shape.  Thus, no COVID-19 particle can attach to the ACE2 receptor – even ones that haven’t been surrounded by NMT5.  Stuart Lipton, a professor at The Scripps Research Institute, states that “what’s so neat about [NMT5] is that we’re actually turning [SARS-CoV-2} against itself”, as particles surrounded by NMT5 serve to limit the ability of other SARS-CoV-2 particles.  The drug has excited scientists studying SARS-CoV-2 around the world, as they have “realized [NMT5] could turn the virus into a delivery vehicle for its own demise” (PTI, The Tribune India).

Cell reception and signaling are incredibly important to both viruses and the human immune system.  A virus works by infiltrating a cell through cell receptors that line the outside of the desired cell’s phospholipid bilayer.  Viruses attach to these receptors and infect the cell as a result.  SARS-CoV-2’s process is depicted below, as it attaches to the ACE2 receptors described earlier.  The immune system works by recognizing the virus at hand and signaling B-Lymphocytes and T-Lymphocytes to destroy the virus and infected cells.  B-Plasma cells surround the virus, as shown below, which neutralize it and allow it to be engulfed and destroyed by macrophages.  Cytotoxic T-cells kill cells already infected by the virus.  Both B and T Lymphocytes are activated as a result of T-Helper cells, as T-Helper recognize the virus when a piece of it is displayed at the end of a macrophage, and signal the Lymphcytes by releasing cytokines (another example of cell reception and signaling).  This process is all shown in the image below, with the specific virus depicted being SARS-CoV-2.

Fphar-11-00937-g001

However, NMT5 prevents the initial infection from happening when SARS-CoV-2 enters the human body by bonding with SARs-CoV-2 particles before they attach to cells, which allows for the immune system to quickly destroy the virus.  By blocking SARS-CoV-2’s access to receptors, the drug stops the particle before it can infect a cell and do any damage. Since cell receptors are specifically shaped, and any change in form results in a loss of normal function, the ensuing change in shape of a receptor limits any SARS-CoV-2 particle from attaching to said receptor, further limiting the virus’s damage by blocking cell reception from occurring. Thus, the immune system kills the virus without major symptoms.

All in all, the development of NMT5 is exciting for scientists all around the globe.  If it is as effective as studies show, it could play a major role in limiting the effects of SARS-CoV-2.  Hopefully, all goes well, and you should be hearing a lot more about the drug sometime soon.

If you have any updates or questions on NMT5, I invite you to share them in the comments below.  Thank you for reading my blog post, and stay curious!

Afraid of needles? No Problem- inhale a covid vaccine!

Its been a few years now since the first COVID-19 vaccine became available to the public. And since then, there has been a multitude of people who have been hesitant to receive a vaccine. Some people don’t believe in the vaccine – or even in the virus itself, some are just anti-vaxxers, some however, are simply afraid of needles. A Chinese pharmaceutical company based in Tianjin, China, CanSino Biologics, has recently created a COVID-19 vaccine you can inhale – and hopefully with this introduction, people will be more likely to get vaccinated as the “fear of the needle” with disappear.

The vaccine is called, “Convidecia Air.” And while you may be skeptical about it since it’s not really a “real vaccine that is injected into your body, the nasal flu vaccine has been around for years now and it enters your body the same way as Convidecia Air. I have personally received both the nasal vaccine (the one you inhale), and the needle vaccine (injection) from the flu, and I feel that they have worked the same in the past- which is why I’m optimistic about Convidecia Air.

CanSino Convidecia

As we’ve talked about in AP Biology recently, a regular (via injection) COVID-19 vaccine enters your body, and T-lymphocytes and B-lymphocytes remain in the body as a result. These lymphocytes function as both a Cell-Mediated Response and a Humoral Response, respectively, to try to fight off invading pathogens and prevent re-infection. With this new vaccine that enters the body via inhaling, the same T-cells and B-cells remain in the body after it is introduced to you.

 

CanSino Biologics logo

The introduction of this new type of COVID-19 vaccine seems promising to scientists, as by entering the body the same way as the actual SARS-CoV-2 Virus- through the lungs and mouth- scientists believe that an inhaled vaccine might be more effective in terms of preventing disease and stopping the spread since it is also enters the body via the lungs and mouth.

Overall, scientists are hopeful that with the introduction of this new type of “inhaled COVID-19 vaccine,” people will remain healthier, and the pace at which the world recovers during its post-pandemic state will increase.

 

Is the recently discovered hidden cavity on the SARS-CoV-2 protein a target for drugs?

Many of us have been vaccinated against COVID-19 and have had the virus, leading us to become used to the virus being prevalent in our lives during the past few years. Even though a successful vaccine has been rolling out for a while now, new therapies have not yet been discovered for future strains. Finding new therapies for the virus remains a major priority in the field of science, even if many of us have been protected already. This issue remains a priority because new variants and strains have been continuing to emerge, and some resist present therapy mechanisms.

SARS-CoV-2

The most effective approach to attempting to combat the virus is addressing the proteins on the surface of therapeutic targets, known as spike proteins. The spike protein (S proteins) located on the surface of the virus leads to its spiky protrusions, and its mechanism to enter human cells. Like we learned in AP Biology class, the spike proteins of the virus latch to cells by matching with a specific receptor on a cell’s surface. The spike proteins of the virus have to latch on to the new cell to infect. Successful messenger RNA vaccines properly target this spike protein, which is the main goal when creating new therapies for viruses. 

                                             Spiky appearance of SARS CoV-2 virus

Luigi Gervasio, a chemistry and structural/molecular biology professor at University College London, and his team have been working towards addressing this issue. By partnering with the University of Barcelona’s research team, the two teams took the first steps to discover a possible mechanism for future drugs to detect and protect against the SARS CoV-2 Virus. Through thorough research and investigation, they uncovered a “hidden” cavity on the surface of a prominent infectious agent of the virus known as Nsp1. The team was able to make this discovery by testing small molecules that had the potential to bind to the Nsp1 cavity. The team identified one, 5 acetylaminoindane, which is essential for the development of new drugs against viruses. They concluded that this cavity permitted the calculation of the cavity’s atomically spatial arrangement, which will allow the development of these drugs.

The results of their breakthrough findings set the stage for developing new therapies that will be able to target the NSp1 protein against SARS-CoV-2 and present Nsp1 proteins in future coronavirus strains. Not only will this finding be impactful for targeting SARS-CoV-2 and future variants, but also new cavities on the surface of other proteins that have yet to be found by scientists. Finally, this research is monumental for both SARS-CoV-2 and virus treatment in years to come!  

 

The Science Of Addiction

Overview of the brain

There are three main parts of the brain: the cerebrum, the cerebellum, and the brain stem. The cerebrum controls most of our functions such as movements, thoughts, and even our senses. The cerebrum is roughly two-thirds of the brain as a whole and is divided into four lobes: the frontal, parietal, temporal, and occipital. These lobes control emotions, pain receptors, hearing, vision, and more. Second, the cerebellum is located right behind and a little below the cerebrum, and controls most of our motor functions. Finally, the brain stem is the smallest portion of the brain, sitting beneath the cerebrum and in front of the cerebellum. The brain stem controls both breathing and heart rate, making it just as important as the other parts of the brain regardless of its small size.

Diagram of the brain. Wellcome L0008294

Addiction 

Abusive drugs increase the amount of dopamine in the brain which is produced by the brain stem. Often brain activity that would often be seen from a simple social interaction or through eating food will be seen after addictive drugs are consumed, but the activity will be much more powerful and persistent, leading to the addiction. The brain recognizes the pleasure the drug may grant the user and this numbs the user, over time, to natural releases of dopamine. Further, a study conducted on mice proved that the prefrontal cortex controls social behavior and as social behavior is affected by addiction, one of the major parts of the brain is damaged by drug use.

Connection to biology

The original article articulates how drugs of abuse target circuits in the brain and affect how the reward centers are damaged by drug use. Further, the article focuses on how cortisol levels can affect how quickly a person can recover from an addiction. This is important for addiction research as recovery windows will be more accurate if doctors can test how much cortisol a person has. However, this is not nearly as important as the study of the effects drugs have on our brains. This connects to our biology class so far this year as the plants we’ve been experimenting on in the lab have been watered daily. However, if we suddenly just decided to stop watering them the plants would have the same reaction as someone who was addicted to drugs being cut off: yearning for what was taken from them. In the same way that plants depend on water, a drug addiction makes the addict depend on the drug for functionality as the person’s brain is so damaged that it can no longer produce dopamine without synthetic production through drugs.

Smilies for Article Feed Back

 

Scientists Discover Super-Protein Involved in Gene Replication

For over 50 years, it has been believed all factors that control gene activation in humans were identified and known to scientists. However, researchers from the University of California San Diego and Rutger’s have proved this theory wrong. 

Collegiate professors, and now pivotal contributors to modern science Dr. Jia Fei and James Kadonaga, have discovered a new protein that is involved in the regulation of RNA polymerase. Called NDF (nucleosome destabilizing factor), this gene-building molecule not only unravels nucleosomes, but also “turbocharges” RNA polymerase as it works its way along the DNA strand, improving the synthesis of replicating RNA.

But that’s not all this protein has to offer: NDF has also been found to be in an array of species and organisms, ranging from yeast particles to mammals. This widespread presence suggests that NDF is an ancient factor in the process of gene activation, and has been here since the very beginning. 

NDF works by first interacting with nucleosomes in cells, and then goes on to facilitate transcription– in other words, to replicate strands of RNA. Enzymes called RNA polymerases then come into play, and copy the RNA via dehydration synthesis. This process includes removing oxygen molecules and hydroxides from each nucleotide to covalently bind them together, producing a waste product of water molecules and, finally, a copy of the RNA strand. 

While this newly discovered protein is crucial for the elongation of RNA strands in many organisms, it is especially abundant in humans. Kadanoga reports that it is “present in all [our] tissues,” particularly in stem and breast cells. This makes sense, as NDF has actually been linked to breast cancer; Abnormally high levels of this protein lead to hyperactivity in gene synthesization, which increases the chance of a mutation occurring, and thus cancer. 

With all the remarkable characteristics of NDF, it is crucial that scientists today continue to explore the capabilities and effects of this gene-activating protein, and use it as a basis for studying diseases and phenomenons that occur in the process of gene replication.

RNA recognition motif in TDP-43 (4BS2)

Depiction of RNA strand.

AlphaFold: Is Artificial Intelligence Taking Over?

In this news article by  she talks about a new deep-learning artificial intelligence system called AlphaFold. The purpose of this new technology is to predict the 3-D shapes of proteins by recognizing patterns in structures. At its first release in 2021, the AlphaFold included predictions for most known human proteins, with predictions of over 350,000 protein structures. Since its initial release, the AlphaFold database has increased the number of protein structure predictions to over 200 million.

Confidence alphafoldAF-Q63HQ2-F1

As you can see by the model, some parts of the prediction are more or less accurate than others. One of the main issues with AlphaFold is the fact that these are only predictions. Scientists cannot use this information with full confidence and require further experiments to be able to be confident in the findings. Even with this issue, scientists and researchers have been able to develop potential new vaccines, improve their understanding of diseases, and gain insight into human evolution with this new artificial intelligence system.

As you may remember from your AP Biology class, protein structures are extremely important in allowing the protein to perform its job. Proteins are extremely integral in your body’s ability to function. Enzymes are used to speed up reactions, antibodies protect our body from diseases, hormones send signals to the body, etc.  By knowing the structure of the protein, scientists gain a better understanding of how proteins and all of these processes work. Just by changing one amino acid, the whole structure changes which can cause diseases such as Sickle Cell Anemia. If you would like to learn more about other important purposes of protein structure, this article goes into more in-depth on the applications of protein structure and modeling.

Now onto the topic of artificial intelligence as a whole. While artificial intelligence can reduce human error, take risks instead of humans, create unbiased decisions, and automate repetitive actions, it also has several downsides(besides the possibility of it becoming sentient and taking over the world like in movies). Some of these are having high costs, increasing the amount of unemployment, being emotionless, having no morals, and making humans lazier. Artificial intelligence has the potential to completely change society as a whole. I believe that as long as we are able to keep artificial intelligence under control and not let it get into the wrong hands, it will be a great benefit to society through important breakthroughs, such as AlphaFold, and new ideas that would have never been thought of without the use of this technology.

Do you believe artificial intelligence will be the salvation for humanity or will it be its downfall?

CRISPR Mini | New Territory Unlocked

For over a million years, DNA has centered itself as the building block of life. On one hand, DNA (and the genes DNA makes up) shapes organisms with regard to physical appearance or ways one perceives the world through such senses as vision. However, DNA may also prove problematic, causing sickness/disease either through inherited traits or mutations. For many years, scientists have focused on remedies that indirectly target these harmful mutations. For example, a mutation that causes cancer may be treated through chemotherapy or radiation, where both good and bad cells are killed to stop unchecked cell replication. However, a new area of research, CRISPR, approaches such problems with a new perspective.

The treatment CRISPR arose to answer the question: what if scientists could edit DNA? This technology involves two key components – a guide RNA and a CAS9 protein. Scientists design a guide RNA that locates a specific target area on a strand of DNA. This guide RNA is attached to a CAS9 protein, a molecular scissor that removes the desired DNA nucleotides upon locating them. Thus, this method unlocks the door to edit and replace sequences in DNA and, subsequently, the ways such coding physically manifests itself. Moreover, researchers at Stanford University believe they have further broadened CRISPR’s horizon with their discovery of a way to engineer a smaller and more accessible CRISPR technology.

This study aimed to fix one of CRISPR’s major flaws – it is too large to function in smaller cells, tissues, and organisms. Specifically, the focus of the study was finding a smaller Cas protein that was still effective in mammalian cells. The CRISPR system generally uses a Cas9 protein, which is made of 1000-1500 amino acids. However, researchers experimented with a Cas12f protein which contained only 400-700 amino acids. Here, the new CasMINI only had 529 amino acids. Still, the researchers needed to figure out if this simple protein, which had only existed in Archaea, could be effective in mammals that had more complicated DNA.

To determine whether Cas12f could function in mammals, researchers located mutations in the protein that seemed promising for CRISPR. The goal was for a variant to activate a protein in a cell, turning it green, as this signaled a working variant. After heavy bioengineering, almost all the cells turned green under a microscope. Thus, put together with a guide RNA, CasMINI has been found to work in lab experiments with editing human cells. Indeed, the system was effective throughout the vast majority of tests. While there are still pushes to shrink the mini CRISPR further through a focus on creating a smaller guide RNA, this new technology has already opened the door to a variety of opportunities. I am hopeful that this new system will better the general well-being as a widespread cure to sickness and disease. Though CRISPR, and especially its mini version, are new tools in need of much experimentation, their early findings hint at a future where humans can pave a new path forward in science.

What do you think? Does this small CRISPR technology unlock a new realm of possibility or does it merely shed light on scientists’ lack of control over the world around us?

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