Myostatin Mutations

Many people strive to be stronger. There are even those who spend hours working out daily and eat high-protein diets to sustain their muscle growth. When we see someone that is completely ripped, we may think something along the lines of "Do they even have time for anything else?" While muscle growth does typically require much effort, if genes involved in muscle growth are mutated in a specific way, then muscles can be altered without a shred of intentional effort.

       Such is the case in Belgian Blue cattle (image below). These cattle have been selectively bred for many years since muscle mass in cattle often means more meat and money for breeders. For a long time, the more muscular bulls and cows were chosen for breeding, and this resulted in more muscular offspring. What breeders didn't necessarily understand, was that they were selecting mutations in the myostatin gene. This gene codes for the protein myostatin which inhibits muscle development. The mutated, shorter form of myostatin doesn't function properly, which results in more rapid muscle growth. This creates "double-muscled" offspring that, instead of having the normal amount of muscle fibers at birth, actually have twice as many muscle fibers. The myostatin mutation is considered a permanent muscle mutation within this cattle breed.

But myostatin has the same muscle-inhibiting function in other mammals. Mutations of myostatin have even been found in humans. Several cases of children born with these mutations have been documented, but have only recently been understood (image of boy with a myostatin mutation below). Additionally, myostatin mutations have been induced in mice to create "mighty mice" by Se-Jin Lee and colleagues at Johns Hopkins. Below, there is an image of a normal, wild-type mouse that lacks any myostatin mutation and a mouse with mutated myostatin. You can clearly see that the mutated mouse has much more muscle mass than the normal mouse. The discovery of myostatin mutations and their effect on increased muscle mass has practical applications. These mutations are currently being studied to potentially help people with muscular dystrophies (conditions with weakening muscles).

Link to primary article about Myostatin mutation:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC24998/

Can you Ear me now?

Doctors in China are growing a new right ear for a man who lost his in a car accident. Not in a petri dish in a lab, but on the man's own arm! Dr. Guo Shuzhong, a reconstructive surgery specialist, is leading a team of doctors in a 3-part plan. In the first phase, the skin was expanded on the patient's arm using injections of water. In the second phase, some of the patient's own cartilage, shaped into the form of an ear, was placed into the arm to grow. In the third and final phase, the doctors plan to transplant the new ear onto the patient's head.

This isn't the first case of ears being grown on arms. An Australian artist by the name of Stelarc elected to grow a third ear on his arm for the sake of art. Although the ear isn't yet used for hearing, he plans to pursue further operations to install a Wi-Fi enabled microphone so that people can "tune in" to his station and listen to whatever his ear is hearing (image of Stelarc and his ear below).

Link to recent reconstructive ear story:
http://www.foxnews.com/health/2016/11/10/doctors-grow-man-new-ear-on-arm.html

Link to video of this reconstructive process:
http://www.wsj.com/video/chinese-doctors-grow-new-ear-on-man-arm/37480AB0-9361-4354-B75E-6C7CB273FED2.html

Link to 2015 Stelarc story:
http://www.cnn.com/2015/08/13/arts/stelarc-ear-arm-art/

Thanksgiving, Wine, and Bluebirds

Thanksgiving has come and gone, and we all likely feasted on turkey or ham, stuffing, potatoes, pumpkin pie...and maybe a glass or four of wine. Since wine is so often enjoyed, and wine-making can be very profitable, many researchers out there are studying what makes wine better. Still, before grapes are even collected, they are obviously grown in vineyards. A recent study looked into how vineyards may benefit from other animals in the environment: bluebirds.

Unfortunately, trees that house bluebirds are frequently cut down to make room for expanding vineyards. This study examined whether putting up birdhouses (for the bluebirds to live in) is beneficial to vineyard owners. To do this, they collected fecal samples from many bluebirds in Napa Valley, and analyzed the poop for DNA fragments (a process they called "molecular scatology"). The researchers used readily available databases to match the DNA fragments they found in the bluebird poop to the DNA of known species. In other words, they figured out what the birds had been eating.

When they compiled their findings, the researchers saw that bluebirds generally eat a lot of herbivorous insects (mosquitoes and other species), and only about 3% of their diets are from predatory or useful insects. From the standpoint of winemakers, this is a really good thing! It means that the bluebirds are consuming the insects that could potentially eat or damage their crops. Also, we didn't know that bluebirds eat mosquitoes (insects that are not just annoying, but also can spread harmful viruses). These findings might encourage winemakers to install more birdhouses, which would benefit the birds, the winemakers, and all of us happy consumers of wine.

Check out this link to learn more:
http://www.popsci.com/bluebird-poop-proves-their-value-to-california-vineyards

We Are What We Eat

A very recent study by scientists at the University of Oxford reveals an interesting link between organisms and what they eat. To build DNA, an organism must have access to all the right components. If an organism has a restricted diet, and has limited DNA components, then it would make sense that their DNA would be different from an organism that did not have this limited diet. This was the scientists' hypothesis: the composition of food could alter their DNA.

To test their hypothesis, they examined similar groups of parasites that shared a common ancestor but have evolved to eat different food. The researchers developed mathematical models to make DNA comparisons and found that parasites with low-nitrogen diets had DNA sequences composed of less nitrogen than parasites that ate nitrogen-rich food. Interestingly, they also found that it's possible to predict diets of related organisms by comparing their DNA. The authors believe their findings shed light on the mystery of how two highly related organisms can have very different DNA, and also recognize that there are many other factors that influence the DNA of organisms.

Link to review article: https://www.sciencedaily.com/releases/2016/11/161115111720.htm

Primary Reference: 

1. Emily A. Seward, Steven Kelly. Dietary nitrogen alters codon bias and genome composition in parasitic microorganisms. Genome Biology, 2016; 17 (1) DOI: 10.1186/s13059-016-1087-9

Squirrels with Leprosy

Leprosy is a historical disease that has been around for thousands of years. In medieval England, leprosy was a fact of life, with hundreds of care facilities on the outskirts of towns. Although not life-threatening, leprosy is caused by a bacterial infection and visibly damages skin and nerves, making the disease one of deformity rather than death. While rates of leprosy in humans drastically decreased long ago, leprosy has recently been discovered in squirrels in the UK.

Bishop instructing clerics that have leprosy

A paper published on the 10th announced that two strains of leprosy-causing bacteria have been discovered in a red squirrel population in the UK. Previously, only humans and armadillos had been found susceptible to leprosy. One strain found in the squirrels is highly related to the strain that infected people in medieval Europe. Scientists aren't exactly sure how the squirrels became infected with leprosy, but they believe the disease may have been passed between squirrels and humans. This is similar to the few cases of leprosy in the southern U.S. that were transmitted to humans from armadillos. Yet, there is no serious need to fear becoming infected with leprosy, since the disease is now very treatable with antibiotics, and the bacterial strains carrying the disease are quite fragile and often die within a few hours after removal from their hosts.

Squirrel showing signs of leprosy on its ear and muzzle

Link to review article: http://www.popsci.com/medieval-strain-leprosy-found-in-red-squirrels-in-uk

Does This Tickle?

Aristotle was puzzled by an interesting fact: Why can't humans tickle themselves? We have all experienced being tickled at some point or other, but do we understand how tickling works? This is something that some scientists are striving to understand, but not only because of simple curiosity. One tell-tale sign of Schizophrenia is the ability to tickle oneself. Also, tickling is linked to our ability to laugh, play, and simply feel good, so researching how tickling works adds to our understanding of positive and negative emotions, even depression.

Neuroscientists performed an experiment in which they tickled rats and studied their physical and neural responses. They found that the rats learned to enjoy the tickling and even came to think of the hand doing the tickling as their "playmate." The rats displayed a universal expression of positive emotion called "joy jumps" that are also seen in human children, dogs, foxes, and guinea pigs (to name just a few). To record neural activity, the scientists inserted electrodes into the somatosensory cortex of the rats. Cells in this area of the brain increased firing while the rats were being tickled, but also after the tickling as the rats chased the hand and "giggled." Interestingly, when the researchers applied an electrical current to these same cells, this stimulated the rats to behave as if they were being tickled (giggling and jumping playfully). This is important evidence that shows these cells are responsible for ticklishness.

As you might already know from experience, ticklishness also depends on mood. If we are in good moods we are more likely to laugh when being tickled and when we are in bad moods we are likely to complain when we are tickled. They also tested this on the rats by exposing nocturnal rats to a bright light (making them unhappy or anxious) and observing their responses to being tickled. They found the rats were much less ticklish and did not display the signs of playfulness that they did in the previous experiment. Also, the cells in that somatosensory cortex were suppressed, adding evidence to the finding that these cells are required for the typical tickle response. The researchers also came to the conclusion that our brains must form hard-wired connections early in life for the tickling sensation to be learned, and even potentially enjoyed. If we don't experience tickling when we are young, then we are much less likely to enjoy tickling later in life.

Link to video and review of this research:
http://www.sciencemag.org/news/2016/11/watch-these-ticklish-rats-laugh-and-jump-joy

Brain-Spinal Interface: Bypassing Injuries

An international group of scientists collaborated to develop a brain-spinal interface that is able to bypass spinal cord injuries to restore intentional walking in a paralyzed leg. Typically, neurons in the brain work with the spinal cord in order to make walking possible. Electrical signals originating in the motor cortex of the brain travel down to the lower spinal cord where they activate motor neurons that signal muscles to extend and flex the leg. An injury in the spine can cut off this communication. To help regain this communication, a pill-sized brain chip was made and put in the brains of paralyzed rhesus monkeys where it recorded signals from the motor cortex. These signals were then sent to a computer for decoding. The decoded neural messages were wirelessly sent to an electrical spinal stimulator implanted below the area of injury. This signaled the spinal nerves to perform locomotion and the paralyzed monkeys were able to walk on a treadmill. The many scientists who played a part in developing this brain-spinal interface are very excited by this progress but stress the importance of further research before this type of interface can be used in humans.

Review: https://www.sciencedaily.com/releases/2016/11/161109133133.htm

Primary study: http://www.nature.com/nature/journal/v539/n7628/full/nature20118.html

Growing Hearts for Transplants

Many people are on waiting lists for organ transplants. Unfortunately, many people will not receive the organ they desperately need. For example, there are about 4,000 people in the U.S. awaiting heart transplants and only 2,500 of these will receive a new heart within a year. Additionally, a serious problem with transplants is the possibility of organ rejection (when the body's immune system doesn't recognize the new organ and instead fights the foreign cells).

Now imagine if human hearts could actually be grown, not taken from an organ donor, but actually grown by scientists in a lab. This would potentially provide many sick patients with the heart they need to survive and wouldn't otherwise receive. This concept is not science fiction. Scientists have been working on growing organs (ears, lungs, bladders, windpipes etc.) that are specifically designed for their recipient. The process works by using a scaffold of the particular organ (like a template) and seeding the scaffold with stem cells derived from the patient (building upon the template). This means that the organ will not be rejected by the patient's immune system since it was formed from his or her own cells. 

Recently, scientists from Massachusetts General Hospital and Harvard Medical School have grown full-sized, beating human hearts using stem cells. First, they take skin cells from the adult patient and genetically reprogram them to make them into stem cells (called Induced Pluripotent Stem Cells or IPS cells). Then, a donor heart that is deemed unfit for transplantation is washed with a detergent and many of its cells are stripped away, leaving the heart scaffold. At this point, the patient's reprogrammed stem cells are applied to the scaffold where they take hold, grow, and divide. After about 2 weeks in a nutrient-rich solution, the heart looks like a developing human heart and even beats when given an electrical signal! 

While not quite ready for transplantation into patients, this research provides much hope to those that need a heart transplant. Researchers are now trying to increase the number of IPS cells they can create, as well as speed-up the cell maturation process. 

http://www.popsci.com/scientists-grow-transplantable-hearts-with-stem-cells

Images: Stripped human heart (left) and heart grown using a scaffold and IPS cells (right)

Animal Cloning

Let's talk about the cloning of animals. For many of us, the first thing that often comes to mind is the famously cloned sheep named Dolly. Cloned by Scottish scientists in 1996, Dolly was created by a process called somatic cell nuclear transfer which basically means that a cell nucleus from an adult sheep  (which contains the genetic information) was placed inside an unfertilized egg that had previously had its original nucleus removed. The developing blastocyst is then placed in a surrogate mother where the rest of development occurs. Not without a sense of humor, Dolly's creators named her after Dolly Parton (for two large reasons) since she was cloned using a mammary gland cell. One important fact about Dolly is that she was able to successfully reproduce and during her life she gave birth to 6 lambs (image below shows Dolly with her first lamb "Bonnie"). Ultimately, Dolly developed a progressive lung disease and arthritis that led to her being euthanized in 2003.

Because Dolly the cloned sheep was created 20 years ago, it isn't surprising that other animals have been cloned since her time. In fact, many other large mammals have been cloned including pigs, goats, horses, cows and bulls. Companies can even select prize-winning bulls and use them in the cloning process to create many other valuable bulls. Meat products from cloned animals have regularly been sold in the United States since 2008 when the FDA decided that cloned meat from these animals is just as safe for consumption as food from traditionally-bred animals.

On a different note, many of us develop strong bonds with our pets. Well, several hundred cloned pets (mostly dogs and cats) have been created throughout the world. The price tag is high and ranges from about $30,000 to about $160,000 depending on type of animal and which company you choose to go with. Still, if you have the desire and funding, you can re-create your current pet many times over. Below is an image of a couple who paid $155,000 to clone their pet dog. The wife holds a picture of their deceased dog (Sir Lancelot) while the husband cuddles the new puppy fittingly named Lancelot Encore.

Fall Back, But Stay Sunny

I don't know about you, but this past weekend I was excited to get an extra hour of sleep thanks to Daylight Saving Time. Yet, whenever we manipulate our normal body rhythms there may be other effects we don't quite predict (and I'm not talking about an extra glow due to additional beauty rest). Recent research has shown a link between setting the clock back and increased rates of depression. This is likely due to less sun exposure and thus a decrease in serotonin levels in our brains. To combat these negative effects, researchers suggest we purposefully try to spend time in the sun each day. Follow the link below to watch a short video about these interesting findings.

https://www.sciencedaily.com/videos/461d48f310bcb471fce60e0472750231.htm

Fruit Flies and Testes: A Useful System

One model system for studying development and other phenomena is the testis of the fruit fly (Drosophila). Below is an image of two adult testes from a single fly that have been immunostained to identify different cell types within the testis.

Genome Editing by CRISPR-Cas9

CRISPR-Cas9 is a revolutionary tool for editing genomes. This tool allows scientists to target a specific sequence of DNA and introduce a change (or mutation) to the DNA sequence. Compared to previous DNA-alteration techniques, CRISPR-Cas9 has the potential to be faster, cheaper, and more accurate. While very promising in areas of molecular biology such as disease treatment, the actual use of such a powerful tool remains controversial. Still, the controversy didn't hold back Swedish scientist Stefan Jansson who recently enjoyed a pasta dish containing cabbage altered by CRISPR-Cas9 technology. Satisfy your curiosity (or hunger) by clicking on the link below.

http://www.sciencemag.org/news/2016/09/did-swedish-researcher-eat-first-crispr-meal-ever-served