Adaptations of the Rock Pocket Mouse

         Throughout the the southwest United States and Mexico, a tiny rodent, called the Rock Pocket Mouse, lives in the rocky deserts. Light brown sand covers most of the desert, and has for quite some time. About 1.7 million years ago, volcanic eruptions spewed lava into the desert causing portions of the land to be fractured with dark black colors. For the pocket mice, this was a huge ecological change, which in turn resulted in a rather fascinating genetic phenomenon.
         Currently, two forms of pocket mice exist. One dark colored, and one light colored. From an biological standpoint it might be rather easy to see why the two coat colors exist. Mammalian and avian predators have perfectly modeled out what is known as natural selection. Natural selection is a process in which organisms most fit for their environment survive and produce offspring. Having this knowledge, it makes sense that the mice living in the brown sand environment have a brown coat, and the mice living in the dark lava colored sand have a dark black coat. Their coat colors clearly emphasize the importance of a tactic animals use crypsis, which is essentially camouflage. Natural selection has driven these animals to evolve based on their environment being more brown, or more black. Now, these mice have different phenotypes for coat color, but the story becomes more interesting when we start to analyze the genetic information about the mice coat colors.
       Researchers have worked diligently in recent years to try to find correlation between ecological and environmental changes, and changes in animal genetics. However, in order to do this, the biologist working on the project must have a solid understanding of genetic information of the animal they are working on, AND then compare it to how the environment has newly changed that genetic information. Luckily for the researchers in the rock pocket mice, many studies have been done on the pigmentation of laboratory mice, which lended a hand in the study done on the rock pocket mice. Due to the pocket mice wild nature, they are hard to breed in captivity. This made crossing them with each other almost impossible. Instead, researchers studied the current mice comparing them with lab mice and came up with some interesting results.
     In the lava dwelling mice, four mutations were found in the MC1R gene. The MC1R plays a crucial role in normal pigmentation. From the information gathered, it was concluded that the dark colored coat was more dominant that the light colored coat, which is consistent with the observations seen on laboratory mice. All mice with that were homozygous dominant, or heterozygous dominant showed a dark coat. The change of just 4 nucleotides seem to have caused the drastic shift from a light brown, to a dark almost black coat color. These studies leave scientist to even more questions. In the dark colored sand, approximately 9% of mice are born with a light coat, and 89% are born with a dark coat. Since selection is driving these phenotypic changes, this makes perfect sense. But does this mean that all the mice in light-colored sand area have only recessive genotypes? In the future, researches hope to answer two questions that have arisen: 1.) Has the color change in mice been driven by a single nucleotide, and the other 3  have just come along for the ride? *or perhaps* 2.) It takes multiple nucleotide variants to produce the colored phenotype of the rock pocket mouse?
     This was an awesome article to read up on because it really shows how LITERALLY one nucleotide could potentially change the whole future of a species. If what the study suggests is true, imagine if the mutation of the MC1R never occurred, and all the mice stayed light colored. The species would probably not even be able to continue on because the light colored mice would be eaten by prey. It's amazing to think that one nucleotide changed the whole course of the rock pocket mouse's future.

https://www.pnas.org/content/100/9/5268
https://www.ncbi.nlm.nih.gov/pubmed/12704245
https://learn.genetics.utah.edu/content/selection/comparative
https://www.biointeractive.org/classroom-resources/making-fittest-natural-selection-and-adaptation

Red Hair, Vampires, Red-Headed Irish Leprechaun and Many More

It was historically known that in certain countries and cultures, people who had red-hair were considered to have a bad genetic trait. It was strongly associated with strong-willed, mischievous bullies. ''Gingerphobia'' was a termed that was coined to describe the fear of red-heads and ''gingerism'' is the bullying of or prejudice against redheads. In Egypt, it was known that people who had red hair were burned. People with this color hair have some interesting medical facts; they tend to be left-handed and less sensitive to absorption of Vitamin D. Red-hair is a recessive trait and is often associated with low concentration or the absence of melanin. It a secondary mutation of the melanocortin 1 receptor (MC1R) gene, found on the 16 chromosome. This mutation can be found around the world but it is most common in Scotland. 

This is connected to genetics since this is a genetic mutation. Having red hair is a rare and it was also historically badly seen as a bad trait just like previous or present day rare traits. 

http://health.usnews.com/health-care/for-better/articles/2017-03-17/genetics-the-common-thread-of-redheads-st-patrick-vampires-and-culture

Red Heads Are Not Only Crazy But More Likely To Get Cancer As Well

It's a hot summer day at the beach and all you want to do is run into the cold ocean to cool off but there's always that one adult yelling at you to put sunscreen on before hand. We've all experienced that moment where we're thinking to our selves "I don't need sunscreen I won't be in the sun long anyway." Applying sunscreen is a hassle but for redheads this may actually save your life!

Skin cancer is the abnormal growth of skin cells- most often develops on skin exposed to the sun.

Skin cancer can be cause by the UV radiation from the sun coming in contact with your skin. Sunscreen acts as a protective layer between your skin and to some of the UV radiation the sun admits. It helps block the negative effects that UV radiation can cause on our skin cells. In a recent study it was shown that people with the red hair gene along with the pale skin and freckles gene are more likely to develop skin cancer due to a larger amount of genetic mutations. The red hair variation of the

MC1R gene had 42 percent more mutations than those without the red hair gene.

This difference in percentage between those with these genetic mutations and those with out would be equivalent to an extra 21 years of exposed sunlight. Redheads who also have pale skin and freckles have two copies of the MC1R gene whiles non redheads who are pale skinned and have freckles only have one copy. Those who only have one copy are also at an increased risk for developing skin cancer. 400 people's DNA, who have tumors, were sequenced and it was found that just having one copy of the MC1R gene increased the genetic mutations greatly. In the future more studies will be run to try and lessen the risk for developing cancer for these people with the copy of the MC1R gene. About 2 percent of the world are redheads meaning there are a lot of people at risk for developing skin melanoma, one of the most fatal types of cancer.
 

A Gene That Affects How You Age

Subconsciously humans make decisions based on the appearance of someone else’s face. This could be reading the body language to see if one will have a peaceful or aggressive encounter. Also, if someone is physically attracted to another all occurs subconsciously. In recent studies, scientists have discovered a gene that affects aging in human faces. 

Aging cannot be explained on a single gene. However, the discovery of this gene will open the doors to new research. The researchers of Manfred Kayser Erasmus Medical Center studied more than 8,000,000 DNA variants. Through previous studies, the researchers identified a correlation between “how old” one appears to their relative health. As a result, the researchers used genome data of 2,600 adults and found a gene that affects facial age call MC1R.

People who had a particular variation of MC1R appeared to be two years younger than their actual age. This was independent of chronological age, sex and the amount of wrinkles. MC1R codes for the production of melanocortin 1, which plays a key role in the coloration of skin, hair, and eyes. A reduction of MC1R increases the chances for skin cancer.  Currently, researchers are unaware how the variation in MC1R causes a more youthful appearance, as more research is required.

Original Source: http://www.medicalnewstoday.com/articles/309568.php

Additional Readings: http://www.techtimes.com/articles/58651/20150608/researchers-find-genes-that-can-make-you-look-younger-by-10-years-fountain-of-youth-within-humans.htm

Gene May Raise Melanoma Risk, Even Without Sun Exposure

Melanoma is a type of skin cancer that is a tumor of melanin-forming cells. Melanin is a specific type of skin cell. There are various ways to get melanoma but too much sun exposure is usually the most common. There has been new research that shows that sunburn may not be only way to get it. The research shows that genetics may play a key role in the development of this cancer. Despite the research that has been coming out, experts say that people should still use proper caution while sunbathing. Too much sun is proven to cause melanoma. Neil Box, assistant professor of dermatology at the University of Colorado Anschutz Medical Campus says that in order to prevent melanoma, none of the current recommendations should be changed. An expert dermatologist, Dr. Jeffrey Salomon who is a professor of surgery at Yale University School of Medicine, has said that genetics is a big factor of getting melanoma. BRAF gene mutations can be tied to 40 and 60 percent of all melanoma cases. There have been new medications that fight this cancer and the results have been showing to help significantly. Melanocortin-1 receptor, or MC1R, gene affects ones skin pigmentation. Dr. Wendt from the Medical University of Vienna has led new research on studying variations of this gene. Red haired people were said to be at the highest risk of getting melanoma due to this gene. The experiment included about one thousand people with melanoma and about 800 people who did not have melanoma. About 47 percent of the people with melanoma said they had 12 sunburns in their lifetimes, compared to 31 percent of people showing that too much sun was the cause. 41 percent of the people with melanoma also had at least two variations of the gene. After examining the results, questions are still raised whether or not people that have these gene variants have a higher risk of getting melanoma. Supposedly the results are not definite and do not prove anything.

The results of these tests are not 100 percent. There is not definite proof that shows that genetics is a huge cause of melanoma. I think that people should continue to use the proper precautions when enduring long sun exposure. It is known that the sun’s UV rays do cause melanoma. So in order to prevent it, sunscreen should always be worn when someone will be exposed to these harmful UV rays. I believe that researching should continue doing tests to see if genetics actually does determine ones risk of melanoma. However in the meantime everyone should be cautious when out in the sun.

Links:

http://health.usnews.com/health-news/articles/2016-04-06/gene-may-raise-melanoma-risk-even-without-sun-exposure

http://www.cancer.org/cancer/skincancer-melanoma/detailedguide/melanoma-skin-cancer-what-is-melanoma

The Gene Behind a Freckle-faced Carrot Top

Many people believe that freckles come from increased sun exposure. Some believe that freckles are a trait you're born with. Both answers are correct. Well, mainly the second answer, but the first guess isn't too far off. When in direct sunlight, our skin is protected by a chemical called melanin. Melanin helps to increase  the pigment on the skin. Freckles are simply spots where melanin has built up. The build-up is caused by the clumping of melanocytes (they produce melanin) on the skin. People with an even spread of melanocytes, when exposed to UV light from the sun, will burn and tan nicely and evenly. Other people tan just a little bit more at those small clumps and it seems as though their freckles have grown and intensified. Thats the reason behind the common misconception of sun-caused spots. But what actually causes freckles?



Scientists have found the gene that regulates freckles and, not so coincidentally, it also controls the appearance of red hair. This gene is labeled MC1R. The MC1R gene is responsible for creating the MC1R protein that creates and protects the most common skin pigment, eumelanin. When the MC1R gene is broken, it overlooks the other pigment known as pheomelanin and the freckles and/or hair turn red. There are many variables to consider when trying to figure out why someone has red hair and no freckles or vice versa. The easiest and most likely answer is that there is actually another gene in collaboration with MC1R that helps make that decision.