BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: biology (Page 1 of 4)

Stem Cells and CRISPR

Many cells can reproduce but there are a few types of cells that are not able to reproduce. One of these types are nerve cells, the cells that cary messages from your brain to your body.  There are many ways nerve cells can be destroyed or damaged, by trauma or drug use.  Millions of people are effected by losing nerve cells and for so long no one could think of a way to recreate them; until the discovery of stem cells.

After fertilization, and when the newly formed zygote is growing, it is made up of a sack of cells.  Some of these cells are stem cells which develop according to their environment. Because of the behavior of stem cells, scientists theorized that if they placed stem cells in the brain or spinal chord, two areas that have an abundance of neurons, the stem cells would turn into a neuron because of the environment it was in.  But, when they tried introducing stem cells into the body, the immune system treated them as an foreign body, as it should. Our immune system has to treat anything that does not come from our body as an enemy or we could get extremely sick.  However, the downside is organ transplants, blood transfusions, etc. are dangerous because they could cause a serious immune rejection.

Someone experiencing a spleen transplant rejection

Cells have a surface protein that displays molecular signals to identify if it is self or foreign.  Removing the protein causes NK (natural killer) cells to target the cell as foreign. Scientist haven’t been able to figure out how to make a foreign cell not seem foreign until Lewis Lanier, chair of UCSF’s Department of Microbiology and Immunology, and his team found a surface protein that, when added to the cell, did not cause any immune response.  The idea would be to use CRISPR/cas9 to edit the DNA of the stem cells, and in doing so would remove the code for the current surface protein and add the code for the new surface protein.

After the scientists had edited the stem cells, to have the correct signal protein, they released them into a mouse and observed that there was no immune rejection. Truly amazing. Maybe brain damage could be helped by this science one day. Tell me your thoughts on Stem Cells in the comments!

For more information, please go check out the primary source of this article.

 

 

CRISPR Technology is Finding Its Place in the Agricultural Industry

CRISPR technology is now laying a foundation in the agricultural world, trying to help corn growers improve the speed, versatility, and output of their crops. It has been difficult to implement CRISPR technology thus far, as the cells walls of plants, at a microscopic level, are particularly tough to penetrate. Fundamentally, CRISPR “…consists of enzymatic scissors called Cas9 that a guide made from RNA shuttles to an exact place in a genome.” The difficulty with plants cells is that, in comparison to animal cells, the extra-rigid cell walls make it immensely difficult for the guide RNA (gRNA) and the Cas9 to reach their destination on the genome. In response to this problem researchers have come up with what is described as an “inelegant” solution to this problem where they “…splice […] CRISPR genes into a bacterium that can breach the plant cell wall or put them on gold particles and shoot them with what’s known as a gene gun.” Unfortunately, this method doesn’t work in the crucial corn varieties where it is needed. However, a team of researchers in North Carolina, Timothy Kelliher and Quideng Que of Syngenta, in Durham, North Carolina have come up with an even more ingenious solution to deal with the stubborn plant cell walls. Haploid induction “…allows pollen to fertilize plants without permanently transferring ‘male’ genetic material to offspring. The newly created plants only have a female set of chromosomes – making them haploid instead of the traditional diploid. Haploid induction itself can lead to increased breeding efficiency and higher yielding plants.” This same method has been found to work in wheat and even Arabidopsis, “…a genus of plants related to cabbage, broccoli, kale, and cauliflower.” Yet again, sadly, CRISPR faces another drawback as scientist not that “…if it were done in the field, the changes wouldn’t spread because the male genome in the pollen – which carries the CRISPR apparatus – disappears shortly after fertilization.” However, there is still much hope for CRISPR technology, and it is without a doubt that we are making big strides into the future with gene editing technology.

CRISPR/Cas9: Controlling Genetic Inheritance in Mammals

Often the subject of debate, CRISPR/Cas 9 has come to the forefront of the scientific community as its development bridges the worlds of Sci-Fi and reality. Yet while CRISPR/Cas9 has been successfully used in altering the genetic inheritance of insects, applying the same technology to mammals has proven to be significantly more complex. With the recent development of active genetics technology in mice by UC San Diego researchers, a huge stride has been made for the much contested future of gene technology.

Releasing their findings in January, the team led by Assistant Professor Kimberly Cooper engineered a copycat DNA element into the Tyrosinase gene controlling fur color. The copycat DNA results in mice that would have been black appearing white. Over two years they determined the copycat element could be copied from one chromosome to another, repairing breaks targeted by CRISPR.  Ultimately, the genotype was converted from heterozygous to homozygous.

Following the success of her lab’s single gene experiment, Cooper hopes to use the technology to control the inheritance of multiple genes and traits in mice. Her experiment, the first active genetic success in mammals, has biologists hopeful for  future development of gene drive technologies to balance biodiversity and mitigate the adverse effect of invasive species.

Bears Are Adapting To Our Unbearable Drones

A recent paper by Mark A Ditmer’s researchers offers some insight that suggests that American black bears are adapting to the exposure of unmanned drones.

An American Black Bear
Photo Credit: Stephan Oachs

These drones are used mainly for conservation purposes to gather data in various environments. Yet, animals are known to be disturbed by low flying drones, displaying changes in animal behavior when drones are near. In fact, many animals display behavioral signs of fear towards a low flying drone.

However, most recently, Ditmer’s group of researchers discovered American black bears are adapting to the presence of drones after repeated exposure. The researchers performed used drones previously before not using them for 118 days. Afterwards, they began drone tests again. Immediately, using cardiac biologgers, the researchers saw signs of increased tolerance from American black bears to drone presence.

Something to note is that this tolerance to drone exposure is probably species dependent. In particular, more social animals that interact with humans frequently are assumed to have higher tolerance drones. This implies that the American black bear has evolved and habituated to human exposure and, as a result, have increased tolerance after repeated exposure to unique stimuli.

Despite this discovery, Ditmer warns that “close-proximity drones near wildlife should [still] be avoided.” However, he expresses that this new discovery “can provide benefits without long-term high-stress consequences” for drones with conservation purposes.

 

GOC Bypass… The Future of Food?

For years, scientists have been trying to find ways to avoid the imminent world food shortage crisis. Is there a scientific breakthrough that could help the world get more grain yield in plants and help avoid a worldwide food shortage? These are questions that farmers and scientists around the world have been trying to find the solution to for decades. Professor Xin-Xiang Peng, of South China Agricultural University, and his team believe that they have found the answer, a process they call the GOC Bypass method.

Professor Xin-Xiang Peng and his team conducted thorough research on rice plants, specifically, and tried to find a way to further maximize their grain yields. Peng and his team believe that with the growing population of the world and less useable cultivatable soil, scientists must find a way to maximize grain yield, in order to produce more food. After intensive research, Peng and his partner, Zheng-Hui He, believe that they have found a way to partially bypass a process called photorespiration and reuse the materials used in photorespiration in photosynthesis. This process is called GOC Bypass. Xiang and his team bioengineered the CO2 to be diverted from photorespiration and to instead be used during photosynthesis, causing increased grain yield.

Peng and He discovered that bioengineered rice plants have a 27% greater grain yield than normal rice plants. To achieve this, they converted a molecule called glycolate, which is a product of photorespiration, and converted it to CO2, using three rice enzymes: glycolate oxidase, oxalate oxidase, and catalase (AKA GOC). The CO2 was then diverted to photosynthesis, which was able to, in turn, create a higher grain yield as the photorespiration in the rice plants went down by approximately 25% and the net photosynthetic rate increased by about 15%, due to the higher concentrations of CO2 being able to be used for photosynthesis. Thus, increasing the grain yield in rice plants and harvesting more food from the same crop.

Biologically engineering food has been around for most of the 2000’s, but the GOC Bypass method is a new method that could potentially help combat the need for more food, due to the population growth and the decrease of cultivatable land. Peng and He’s research is promising, but it is still in its early stage. So, only time will tell if the GOC Bypass method will be of any use to mankind in the future and if this process can be used with a variety of different crops.

What do you think? Could the GOC Bypass method help solve the worlds emerging food crisis? Only time will tell.

The research is from Zheng-Hui He, Xin-Xiang Peng’s Engineering a New Chloroplastic Photorespiratory Bypass to Increase Photosynthetic Efficiency and Productivity in Rice, at the South China Agricultural University. The research was published by the Molecular Plant Shanghai Editorial Office in association with Cell Press, an imprint of Elsevier Inc., on behalf of CSPB and IPPE, SIBS, CAS.

 

 

 

Is Photosynthesis the Key to World Hunger?

With a global human population growth of about 83 million annually, one of the most pressing questions of the 21st century is how we will support our ever expanding population. A central study apart of the RIPE (Realizing Increased Photosynthetic Efficiency) International project may have found a key contributor to the solution.

Photosynthesis functions using an enzyme Rubisco and sunlight to turn carbon dioxide and water into sugars and oxygen. Overtime, Rubisco has created our oxygen rich environment, and now is unable to discern accurately between molecules of oxygen and molecules of carbon dioxide. 20% of the time Rubisco will grab oxygen instead of carbon dioxide, creating a toxic substance which must be recycled through a process known as photorespiration. Scientists from the University of Illinois and the U.S. Department of Agriculture Agricultural Research Service reported that plants engineered with photorespiratory shortcuts are 40% more productive in real life situations.

Currently being tested with genetically modifying tobacco plants, experts hope to apply this technology to food related crops within the next ten years. This represents a massive feat for addressing world hunger, as 200 million people could be fed with the calories lost to photorespiration in the midwest United States alone. RIPE and sponsors such a the Bill and Melinda Gates Foundation have pledged to allow small farmers (especially in sub-saharan Africa and Southeast Asia) free access to any project discoveries.

Cellular Roadblocks for Immigrants: The Loss of Gut Microbe Diversity

Recent evidence from the University of Minnesota in conjunction with the Somali, Latino, and Hmong Partnership for Health and Wellness suggested that immigrants and refugees moving to the United States were likely to experience a rapid change in their gut microbes. Described as “westernizing” to their environment, immigrants tended to lose their diverse, native microbes in favor of microbes that are common to European Americans.

The participants of this study originated from Southeast Asia, specifically the ethnic minorities of Hmong and Karen from China, Burma, and Thailand. The study used ethnic minority communities from both Southeast Asia as well as those living in Minnesota as a comparison, analyzing the gut microbes in these participants and using Caucasian American people as controls. The researchers also looked into the first generation children of these immigrants. Additionally, the study was able to follow a group of nineteen Karen refugees, tracking the changes in their gut microbes as they traveled to the United States.

The study discovered that the gut microbes in these participants changed rapidly. Particularly, in the group of Karen refugees, the Western strain of Bacteriodes replaced the non-Western strain of Prevotella in the matter of less than a year. Furthermore, the overall gut microbe diversity continued to decrease in all participants in the United States in relation to the length of their stay. Likewise, the children of immigrants had a more profound decrease in diversity. Researchers in this study suggested that this decrease in microbe diversity may have been a result of a Western diet, or for the children, growing up in the United States.

Image result for bacteroides

Closeup of Bacteroides biacutis(Image Credit: CDC/Dr. V.R. Dowell)

 

So why does this matter? Well, the study established a correlation: the greater the “westernization” of gut microbes, the greater obesity in immigrants. This obesity problem appeared to be more prevalent in immigrants, and the study had discovered a key piece of evidence for why.

“When you move to a new country, you pick up a new microbiome.” Dan Knights, one of the key authors of the study as well as a quantitative biologist at the University of Minnesota, says. “…What enzymes they carry…may affect the kinds of food you can digest and how your diet affects your health. This may not be a bad thing, but we do see that Westernization of the microbiome is associated with obesity in immigrants.”

 

What are Biofilms?

 

Biofilm being formed. (Pixnio)

Medicine has made great advancements in patient care and treatment over the last decade. However, everyday viruses and bacteria alike have become stronger and more resilient – even to the latest antibiotics. One such threat that has led to “…thousands of deaths…” in “…American Hospitals alone…” are biofilms. These bacterial cells “…gather [together] and develop structures that bond them in a gooey substance…” insulating them from the outside world. Biofilms ability to become impervious to antibiotics at a moment’s notice has led biologists to wonder both how they develop, and how to stop them.

To find out how and why these bacteria form biofilms, researchers at the Levchenko Lab, at Yale University, as well as from the University of California – San Diego, “…designed and built microfluidic devices and novel gels that housed uropathogenic E. coli cells, which are often the cause of urinary tract infections. These devices mimicked the environment inside human cells that host the invading bacteria during infections.” From this experiment, the scientist discovered that the bacteria would multiply until physical constraints inhibited them from further reproduction. At this point, the bacteria would become “stressed” and thus this “stress would induce the formation of a biofilm.

With the numerous mimicking devices that the researchers utilized in the experiment, they can now create many biofilms in predictable ways, and further analyze their behavior in similar environments. “This would allow for screening drugs that could potentially breach the protective layer of the biofilms and break it down.”  It is an amazing solution to a stubborn and persistent biological threat, that has already robbed enough, otherwise healthy, people of their lives.

It is imperative that we continue to make great strides in the advancement of medical technologies and treatments, as this will enable us to live healthier, more disease-free lives for the future to come. As viruses and bacteria get stronger, we need to make sure to keep up.

Microbiomes… an Athlete’s Key to Success!

For years, scientists have been trying to see what makes a professional athlete different from someone who didn’t quite make the cut. Is there something that professional and elite athletes have that other athletes or inactive individuals don’t? Is it possible to give a mediocre athlete a supplement to improve their performance? Dr. Jonathan Schieman and George Church from the Wyss Institute at Harvard University believe the answer is yes, and they think they’ve found the answer, microbiomes.

Dr. Schieman and his team conducted thorough research on NBA players, marathoners, and Olympic rowers to see if there was a common microbiome that these high-level athletes all shared that sedentary individuals did not. After immense amounts of testing and making sure the proper controls were in place to avoid confounding, and lurking variables, Schieman and his team were able to find one particular organism that was elevated in the guts of athletes’ bodies more than sedentary individuals.

Schieman and his team were able to isolate a particularly abundant organism in athletes that feeds off lactic acid. Lactic acid is a naturally occurring chemical compound that generates during particularly intense and strenuous muscle exercise. Thus, the researchers believe that the organism they isolated has a particularly important effect on making athletes stronger. In addition, the researchers have recently conducted a new study on rugby players and found that rugby players have more of this organism in their body as well as a more diverse range of microbiomes than a sedentary individual.

The microbiome space is particularly new, so one cannot conclude that these findings will be significant to athletes in the future, a realization that Schieman has come to terms with. However, if Schieman and Church find more conclusive and concrete evidence that these, and other, organisms can yield a much better athlete, the sports world could change forever.

What do you think? Can microbiomes be used to make more elite athletes? Only time will tell.

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The research is from Jonathan Schieman and George Church from the Wyss Institute at Harvard University. A comprehensive scientific journal entry has not been released to the public due to intellectual property concerns, as the findings are part of a privately-owned company.

Image: https://commons.wikimedia.org/wiki/File:EscherichiaColi_NIAID.jpg

Can a Fox Be Your New Pet?

The big difference between your dog and a wild animal is the relationship that it has with humans. For example, both dogs and foxes come from the canidae family, however foxes are generally scared of humans  while dogs are “ a man’s best friend”. So why is the fox’s response drastically different than a dogs?

 Scientists may have figured it out. The study was originally started in Russia where a scientist wanted to see if he could domesticate foxes like people had domesticated dogs. He started to breed silver foxes with domestic traits: ones that were more tamed and friendlier towards humans.  But at the same time he also bred foxes that were aggressive to humans in order to make an aggressive breed of foxes. He then started to compare the two breeds as the generations went on. He studied only 10 generations but 50 generations of silver foxes later Cornell did a study on the same foxes.

Cornell studied the tamed foxes’ brains in comparison to the fox’s brain that were aggressive towards humans.  The scientist obtained brain tissue samples from 12 tamed foxes and 12 aggressive foxes looking for differences between the two brains. The particular part of the brain they studied was the prefrontal cortex and basal forebrain which are known for processing more complex information. The prefrontal cortex processes social behavior and personality expression, while the basal forebrain is a critical component to processing memories. The neurotransmitters from those regions were what the researchers mostly focused on. In particular, they focused specifically on the neurotransmitters that release dopamine and serotonin in the foxes brains  which are responsible for feelings of happiness because they trigger the pleasure center of the brain.

Through the study of the neurotransmitters, the researchers found that genes from these sections of the brain from the tamed foxes were altered through the breeding of the foxes but not the ones that they expected.  The variant genes in fact coded for alterations in the  function of the serotonergic neurons and the glutaminergic neurons. Those neurons coincide with learning and memory. This shows that tamed animals learn and memorize differently than their aggressive equals.  Now that we know this do you scientists through genetic modifications will be able to tame or domesticate any animal by simply changing a gene in their brain?

Survival of the Fittest or Laziest?

For hundreds of years biologists have essentially fully accepted Darwin’s theory of “Survival of the Fittest;” but, have they been wrong all this time? Scientists believe that there could be a link from high metabolic rates to extinction. Luke Strotz, scientist and researcher at the University of Kansas, studied the effect of metabolic intake, energy intake by an organism, in mollusks.

Strotz and his team decided to use mollusks as their objects of interest due to the sheer abundance of data that they could retrieve from the past 5 million years. Strotz observed that certain mollusk species with higher energy intakes are extinct; while, mollusks species that have considerably lower metabolic intakes are still in existence today. Thus, in the mollusk group, it was quite clear that the higher metabolic rate correlated with faster extinction. Although this study is quite primitive in nature, and thus should not be compared to humans, it is perplexing to see that a species in the mollusk group can continue to exist because of its “laziness” or low metabolic intake.

Although Strotz’s evidence is convincing, I personally do not believe that “Survival of the Laziest” should be taken seriously, as mollusks are extremely different from humans. Thus, it would be illogical to compare the correlation of this study to that of the lives of humans. So, unfortunately, it appears laziness is most likely not a trait that the human race should endorse.

What do you think? Can laziness really save the human race? Only time will tell.

 

The research from Luke Strotz is published in the journal: Proceedings of the Royal Society B.

 

Advancement in Modern Antiseptics

Before the 1870’s, sanitation was a huge problem in the growing world.  Doctors would clean tools with wine or hard alcohol, people’s teeth were falling out from not cleaning them, and people were getting infections from surgery at an alarming rate, etc.  Since so many surgeries resulted in infections, they then had to amputate that area.  Amputations had a 45-50% success rate.  This all means that if you needed surgery, you probably would die.  It wasn’t until many advances in microbiology that Joseph Lister introduced Carbolic Acid as an antiseptic in medicine.  He discovered that it cleaned surgical instruments extremely well, and prevented many infections from surgery.   This discover made the maternal death rates drop from 18% to 1%.  Later, another antiseptic, Listerine, was made by another scientist for a general sanitation, in which it was named after Lister, the father of antiseptics. 

Joseph Lister, Father of Antiseptics

You might be thinking, “All of this happened in the past, and our antiseptics are so good now, why do should I care?”  As it turns out, modern antiseptics don’t actually sterilize things 100%, and although they do a pretty good job, and there are still new antiseptics being discovered every year.  One of these recent discoveries is an antiseptic for caesarean deliveries.  A new solution of Chlorhexidine and alcohol (2% chlorhexidine gluconate with 70% isopropyl alcohol) cuts cesarean section surgical site infections by half compared with the usual solution of iodine and alcohol (8.3% povidone-iodine with 72.5% isopropyl alcohol). Dr. Methodius G. Tuuli, who is a professor at Washington University in St. Louis, is responsible for this amazing discovery and has spoken at the Annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine, and had his work published in the New England Journal of Medicine.  

The experiment itself consisted of 1,147 patients who delivered a baby through a c-section.  The doctors then randomly used either the new solution or the old alcohol/iodine solution. Besides that, nothing else changed in the procedure for postpartum women; and then 30 days after being discharged from the hospital they were given a call to see if the surgery site had developed an infection. The only downside that is known about Chlorhexidine, is that it supposedly causes more allergic reactions than the iodine solution; however none were observed during the experiment. 

Antiseptics are often overlooked when it comes to the best inventions or discoveries in science because it is so mundane.  People never stop and think what life was like before we had all these amazing soaps and sanitary solutions. To me, it is mind-blowing that less than 150 years ago, if a person needed surgery on any of the limbs,  the odds are they would probably get an infection, then have to get it amputated, which gave them a 50% chance to live.  Do you readers agree that Antiseptics have been our greatest discovery? Let me know in the comment below!

A Fintastic Discovery

Sharks have interesting biological features: a cartilage skeleton, highly developed senses, dermal denticles, and an oil-storing liver. However, these traits are difficult to identify within the huge genomes of sharks.

 

Previously, the genomes for sharks were larger than many other organisms, making it difficult for scientists to decode and understand the genetic background behind the lifestyle of sharks. However, the Japanese team at RIKEN Center for Biosystems Dynamics Research managed to decode whole genomes of two species of shark: the brown banded bamboo shark and the cloudy catshark. They also improved the genome sequences of the whale shark.

Image result for whale shark of sharks

Whale shark Photo Credit: Zac Wolf

Whale Shark

According to the RIKEN team, the large genomes in many shark species was a result of huge, repetitive insertions within the genome. Additionally, it was discovered that these shark genomes have been evolving at a slow rate, suggesting that sharks have kept some characteristics that were similar to distant ancestors.

 

Already, particular parts of the shark genome revealed certain characteristics of sharks. Using the DNA from the shark genomes, researchers discovered that the rhodopsin pigments in a whale shark can sense short wavelengths, allowing them to see at 2000 meters below the water level when they aren’t hunting on the surface. Furthermore, the team determined that there were too few olfactory genes in the shark genomes, meaning that the highly developed navigation system is not done through smell.

 

These results help fill the gaps in the genetic background in sharks while understanding the way sharks live. Keiichi Sato, deputy director of Okinawa Churaumi Aquarium, says, “Such understanding should contribute to the marine environments as well as to sustainable husbandry and exhibitions at aquariums that allow everyone to experience biodiversity up close.”

Clock Change is Actually Great For Your Brain!

November this year, our clocks went back an hour, which accelerated the arrival or darker evenings and seemingly “shorter days”. It doesn’t actually make the days any shorter, in merely just shifted an hour of available daylight from the evening to the morning. Most people take lighter evenings as a priority over lighter mornings, arguments are always made over the benefits for easier travel in lighter evenings from clock changes. However, research suggests that holding onto lighter mornings could give more advantages. Having light in the morning, instead of any other time of the day, leads significant brain-boosting results. In fact, it helps us to function much better.

Early Morning

Credit: Attribution license: Porsche Brosseau

Source

All living animals and plants on Earth revolve their lives around the 24-hour cycle of light and dark. For humans, we desire to sleep during the dark night, and our bodies are honed to environmental light via a biological chain reaction. 

We, humans, detect light intensity by special cells in the retina, then the information is relayed to the internal body clock in the brain, called the suprachiasmatic nucleus. It is in the hypothalamus (which uses the endocrine system to regulate internal body processes), which is linked to hormone secretion, through the pituitary gland. These light messages’ job is to internalize information about light intensity in the surrounding environment.

The chain reaction continues with the brain driving the secretion of the hormone cortisol for a specific time of the day, it is in low levels in the dark and high levels in the light. Cortisol is a very important hormone that has very dramatic effects on the human brain and body. The cortisol is also known as the “Stress hormone” that keeps us healthy through its 24-hour pattern.

The cortisol awakening response(CAR) occurs the first 30 minutes of waking up, it is a strong burst in cortisol secretion. The lighter the mornings, the bigger the CAR. Which directly results in a better functioning brain throughout the day. In an experiment, people who have greater seasonal depression, stress, anxiety and lower arousal exhibited the lowest winter CARs. But when they are exposed to artificial light during their awakenings, their CAR was restored. Thus proving that morning light is the most effective treatment for the winter blues.

Other research has also shown that CAR in the morning is directly linked to better brain plasticity, better goal-setting, decision-making and executive function.

The burst of cortisol secretion in the morning sweeps throughout the entire body where it is recognized by receptors on all body cells. The receptors then generate the biological chain reaction to allow us to function better for the day ahead. A lack of light in the morning can make us feel not functioning fully, and an exposure to light in the morning is extremely beneficial.

Source:

https://www.scientificamerican.com/article/why-the-clocks-changing-are-great-for-your-brain/

To Cooperate or Not To Cooperate: How Motor Proteins Transport Cargo in Cells

By Jzp706 (Own work) [CC0], via Wikimedia Commons https://commons.wikimedia.org/wiki/File%3AKinesin_walking.gif

Have you ever wondered how tiny motor proteins manage to carry cargo inside cells?

As we know, motor proteins called kinesins transform energy from chemical ATP into mechanical action by attaching themselves to large cargoes like mitochondria and pulling them along cytoskeletal filaments. Each kinesin contains two “head” subunits, and each subunit contains two binding sites – one to grip and walk along microtubules and the other to bind ATP. However, few studies have been conducted on motor proteins’ detailed mechanisms.

Recently, Rice University led a study exploring the little-understood topic of the sensitivity of a motor’s velocity in response to a force and the cooperation between motor proteins. The researchers used computer simulations to provide the first molecular-level details of how kinesins respond to external forces. The models showed that the velocity of kinesins is weakly influenced by small to midrange external force but is steeply reduced by a large force: only under large loading forces would the velocity of kinesin be significantly reduced as the motor head releases ATP at a fast rate. Under small to midrange forces, the velocity barely changes.

What’s interesting to note is that the study also confirmed while motor proteins naturally work in teams, two load-bearing kinesins are not able to equally share the load unless they are within the distance of 48 nanometers from each other! As a consequence of such weak cooperation, the trailing kinesin faces the challenge of catching up to the leading one, while the lead kinesin has to take on the responsibility of carrying more than 90 percent of its cargo load. This is because, according to the researching, “the lead kinesin pays more attention to the pull of the cargo itself, which triggers a ‘switch’ in the neck linker that controls the speed. A trailing kinesin that’s too far away doesn’t sense the force and therefore can’t contribute its muscle.”

The study gives an opportunity for future study of similar mechanisms, such as that of dyneins, larger and more complex proteins that move cargo within cells. It also inspires more scientists to research kinesins as defective or deficient kinesins are implicated in certain kidney diseases and Charcot-Marie-Tooth disease.

 

By Boumphreyfr (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

Click here to read the original article. Click here to watch “A Day in the Life of a Motor Protein” and learn more about motor proteins!

How DNA damaged from radiation causes cancer

In a recent study, professors from the Wellcome Trust Sanger Institute sought to see the similarity between spontaneous cancerous tumors and cancer caused by ionized radiation. By looking at the molecular fingerprint of different types of cancers, they were able to differentiate between cancers that formed by radiation and cancers that were not formed by radiation.

In the study, they studied the mutational signatures of the DNA. Mutational signatures are just ways in which the DNA is affected by cancerous mutations. They studied the DNA mutational signatures from DNA exposed to radiation, but not necessarily cancerous, and the mutational signatures of the DNA of cancerous cells of which some were caused by radiation exposure and some were not. Both included the same signatures.

The two mutational signatures that were observed were deletion of segments of DNA bases and balanced inversion, where the DNA is cut in two places, the middle piece flips around, and the pieces are joined back in the opposite orientation from before the flip. High energy radiation is the cause for balanced inversion, since it does not happen naturally in the body. After the mutation, the DNA cannot repair itself.

This gives us a better understanding of cancer and how ionized radiation affects DNA and produces these mutational signatures. Knowing this information, this helps us recognize which tumors are caused by radiation. Once we have a better understanding of this, it will prove important for determining how each cancer should be treated. But for now, this is a strong step forward in the battle against cancer and every step of the way is crucial if we are to be victorious.

 

The Silent Extinction: How an invasive species is likely to destroy the Ash Tree

There is a mass extinction occurring right now all across North America that millions of people have never hear of. First discovered in North America in 2002, the Emerald Ash Borer, an invasive species native to Mongolia and northern China, has destroyed tens of millions of Ash Trees across North America; and it is likely to destroy millions more.

The Emerald Ash Borer does its damage as larvae. They burrow into the bark of Ash Trees to protect against the cold and in the process of this, cut off the nutrients and water the Ash Tree needs. Scientist suspect that the Emerald Ash Borer has been in North America at least ten years before it was detected.

The devastating effects of the Ash Borer go far beyond losing a tree on your property or favorite hiking trail. The destruction of Ash trees could have a chain effect that leads to the endangerment of numerous plant and animal species. The removal of the canopy that the Ash Trees create leads to sunlight hitting spots of the forest floor that it previously did not. This could lead to invasive species of thickets and bushes covering the forest floor, preventing native plants from growing. Which, in turn, would lead to animals that inhabit the forest going without some of their primary food sources.

In the past, invasive insects have been fought by a combination of insecticides, awareness, and felling of infected trees. This proved fairly successful with the Asian long-horned Beetle in Chicago, but the Emerald Ash Borer presents a different set of challenges. Firstly, the Emerald Ash Borer is march harder to spot than the more distinctive Asian Asian long-horned Beetle. Secondly, it is much easier to deal with an invasive species when it is still localized. While the long-horned beetle was still mostly confined to Illinois, the Ash Borer has spread all across the Upper Midwest.

All factors considered, it may seem that there is nothing that can be done. However, with increased awareness, improved insecticides, and new containment techniques there is hope. The fate of millions of Ash Trees depend on that hope.

For more information click here

 

 

 

MAIT Lymphocytes: An Asset to the Future of Type 1 Diabetes


Well, let’s start with what exactly Type 1 Diabetes is. Most notably found in young children (peak ages are 4-7 and 8-10), type 1 diabetes is a chronic condition in which the pancreas produces little to no insulin. Insulin production is crucial because it allows sugar to pass through your cells, lowers the amount of sugar in your blood, and when your blood sugar drops, the pancreas secretes insulin. Can you imagine what this might feel like as a young child?

However, the detection of MAIT lymphocytes could serve as new biomarkers for early detection and prevention for the illness. If you didn’t know, MAIT cells are found in the blood, liver, lungs, and mucosa, defending against microbial activity and infection. Type 1 diabetes is a lifelong illness without a cure, therefore with this crucial discovery, I believe that this will be one of the great steps toward the findings of a potential cure. This lead can serve as an outstanding aspect to the enhancement of one’s quality of life.

Experiments have been conducted where the presence of the MAIT cells, within the data, showed a link between the MAIT cells and metabolic disorders. This paved the way for the discovery of how MAIT cells are directly linked to the destruction of pancreatic beta cells

Additionally, a functional defect in MAIT cells is linked to the modifications of the gut mucosa which is seen in type 1 diabetes patients. The team’s discovery will hopefully translate to a developmental process dedicated to searching for new strategies to treat type 1 diabetes. Overall, we now know that the MAIT cells are early biomarkers for this form of diabetes due to the changes they undergo before the presence of the disease is developed. Do you think more break-throughs will arise in this field? Will there eventually be a formal prevention for type 1 diabetes? Finally, do you think there will ever be a cure to diabetes as a whole?

Everyone Poops (for approximately 12 seconds)

Everyone poops. Despite sometimes causing discomfort and being the subject of juvenile humor, pooping is a necessary, crucial function of our body that removes wastes and can share a lot about a person’s health. All animals poop: Lions, tigers, bears. Celebrities like Justin Bieber and Kim Kardashian, they poop, too. Every species has their own unique way of pooping, with a variety of sizes, shapes, smells, and consistencies. Scientists at the Georgia Institute of Technology have analyzed these differences between animals’ feces and have gained insight on these varieties with a focus on the speed at which animals poop at.

The experiment began at Zoo Atlanta where two undergraduates had the glorious task of examining 34 different species’ poop measuring their density and viscosity. In addition, the animal feces were placed in a rheometer in order to test the consistency of each.

The main finding of the experiment concerned the speed of poop. They found that all animals dedicate in approximately the same amount of time, 7 seconds, despite the varieties is size, consistency, etc. The scientists have found that the reason larger animals, with larger feces, poop at a much faster rate than small animals is because they have thicker mucus lining their large intestine. This mucus is slippery and allows for poop to easily pass; thicker amounts allow pooping to happen faster.

Deficiencies in large intestine mucus can lead to chronic constipation or bacterial infections.

Another source has identified an equation for the speed of poop: “the time it takes to poop is equal to said poop’s length divided by its velocity.” For example, an elephant poops at a rate of 6 cm/sec whereas dogs poop at a rate of 1 cm/sec.

As a young child, I read a book called Everyone Poops.  This wonderful children’s story set to normalize pooping and show that all living things are connected in this way. I am delighted that not only does everyone poop, but everyone poops for about 12 seconds.

Do you feel more connected to other animals knowing we all poop for about the same amount of time?

https://commons.wikimedia.org/wiki/File%3APooping_Elephant_in_Delhi_Zoological_National_Park.jpg Author: Shubhaish kanodia

 

Original Article: https://www.scientificamerican.com/article/the-physics-of-poop/

Fish might be shrinking!

To all the seafood lovers, you are being warned here first! The tiny piece of tuna on your plate will soon become even smaller due to climate change. Fish in the ocean will struggle to breathe due to the increasing water temperature, and many species of fish will likely shrink. According to a study published in Global Change Biology, the author predicts a decrease in sizes of the fish by as much as 30 percent. As Nexus Media explains, fish are cold-blooded animals, which means that they cannot regulate their own body temperature. Daniel Pauly, the study’s lead author and a University of British Columbia research initiative, say that due to the increase in ocean temperature, fish will have a higher metabolic rate and have to consume more oxygen. The whole metabolisms in the fish’s body, all the chemical reactions, are accelerated.

Credit:  Attribution license: Taras Kalapun,

Source

So if the fish need to have more oxygen intake, why not just grow bigger gills? In Pauly’s research, he suggests that growing bigger gills won’t help. According to the article, the gills being mostly two-dimensional, just cannot keep up with the three-dimensional growth in the rest of the fish’s body. When a fish grows 100 percent larger, its gill could only grow about 80 percent or less, according to the study. When a gill can no longer supply enough oxygen for a fish’s larger body, the fish will just stop growing larger all together, according to William Cheung, a director of science for the Nippon Foundation. In order to match the decreased supply of oxygen, fish will have to lower their demand, which means that fish of all kinds will shrink as a result of climate change.

There is already evidence to the phenomena of fish shrinking due to climate change, researchers in the North Sea have found that fish stocks like haddock and sole had decreased in body size over the past couple decades, and it is primarily due to climate change since commercial fishing and other factors have been corrected. Furthermore, the entire ecosystem will be affected since the larger fish eat the smaller ones, and a change in body size would alter food web interactions and structure.

To read more about other impacts of climate change on marine species.

Sources:
https://www.scientificamerican.com/podcast/episode/climate-change-might-shrink-fish/

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