Crossing Over to Blue Eyes

            When we were discussing crossing over, and genetics I was thinking about a question that I had when my daughter was born in 2010. I know that my daughter is a combination of mine and her father’s chromosomes and also our ancestor’s genes, generations and generations of science and biology combining to make up our family. I remember in high school learning that the brown eye gene was dominant over the blue eye gene, which made my question even more baffling. The question that I was going to bring up in class but I decided against is how is it that I am able to have a bi-racial daughter who is African-American and Caucasian and her father and I both have brown eyes, but she was given the most amazing blue eyes that I have seen on a bi-racial person. Now I know that there are blue eyes on both my mothers and fathers side, but not on her fathers’ side…when I was researching articles for this assignment, I came across this article that gave me a little bit better of an understanding. http://news.sciencemag.org/sciencenow/2008/02/01-01.html?ref=hp  “Don’t it Make Your Brown Eyes Blue?”  by Elizabeth Quill February 1, 2008.      

            I know that even though brown eyes dominate over blue eyes there is still a possibility that the offspring of two brown eyed parents can win the crossover and get the blue eyed gene. I was very shocked to get a chance to see the slight probability of this amazing gift unfold in my own daughter that I brought into this world. The HERC2 gene is what I have to thank for this incredible work of beauty, it turns out that this gene that all blue eyed individuals hold can all be traced back to 

a “single common ancestor that was born some 6,000 to 10,000 years ago.”
I know that is not common for infant babies to have blue eyes for the first few months of their lives, which is what I believed was the case in this situation, but a little over two years after the day I was blessed with my angel her eyes are still as gorgeous if not more so than the day she was put into my world. It amazes me that these pretty blue eyes are not only meant for people of European decent, but also that they would not be possible without a mutation of a gene. This mutation that I am speaking of took place somewhere in my family history, made me a part of but somehow managed to dodge my chemical make-up and hit my daughter, this is one of the many miracles of biology and science in general. I know that crossing over was the main function of this whole ordeal and I think that it is really cool to get a first-hand experience to back up this example and give me a reference to relate this terminology to. Desiree Everson

Facial Reconstruction with DNA

Eight years ago, Manifred Kayser, a geneticist at Erasmus MC in Rotterdam, the Netherlands, began to wonder if it would be possible to figure out what genes take part in facial construction (big nose, small forehead, etc.). He thought that if it were possible to do this then eventually there would be a computer program that could use DNA to reconstruct the face, similar to what a sketch artist does with an eye witness.  Before Kayser could conduct any research to find these genes, he and his colleagues looked at MRI images to find different points on the face to work with. The researchers found nine spots on the face to work with. The distance between some spots was also going to be evaluated, such as the distance from eye to eye.

The researchers looked at five groups of people as a part of the International Viable Trait Genetics Consortium, each group contained from 545 and 2470 people. There was one gene that had already been found that correlates to children’s facial shape. This gave researchers hope that they would be able to link other genes to facial features. Before this experiment, other researches had found a gene on chromosome 2 and one on chromosome 3 that are linked to facial problems (cleft lip, deformed jaw). The two new genes they discovered came as a surprise to them.

These five genes are just the beginning of a long process to figure out what other genes contribute to facial features. Researchers say there are many hundreds, or thousands of genes and variants that take part in the process of constructing a face. One researcher thinks that within two to five years there will be some sort of program that uses DNA to create a face. Although it is not certain, these 5 genes give researchers hope that one day they will be able to use DNA to construct a face. Crime labs will benefit in forensic genomics when located a person or identifying a John Doe.

http://news.sciencemag.org/sciencenow/2012/09/five-genes-help-form-a-face.html?ref=hp

 

Calorie restriction falters in the long run

                                   Genetics and healthy diets matter more for longevity.

        In today’s day and age we hear all types of ways to lose weight and the benefits of this. How do we achieve this and what are the positives and negatives of this? In this article they may not necessarily state exactly how to achieve this but, they do discuss the importance of what type of calories we do take in. To quote “When we began these studies, the dogma was that a calorie is a calorie,” Ingram says. “I think it’s clear that the types of calories the monkeys ate made a profound difference” (Ingram from NIA studies).  Granted these studies were on monkeys but these studies do show that if we take in “crap calories” this will be the result. Some may take in fewer calories but in the long run this doesn’t exactly matter in the long run, the types of calories and our genetics matter more.

                They state the in a twenty-five year study from NIA (the National Institute on Aging) that they thought if they fed these monkeys thirty percent less than the control group the monkeys may physically age slower but, instead they learned that the amount of calories isn’t nearly as important as the type of calories.

                “To think that a simple decrease in calories caused such a widespread change, that was   

               remarkable,” says Don Ingram, a gerontologist at Louisiana State University in Baton                     

                 Rouge, who designed the study almost three decades ago while at the National Institute  

                on Aging (NIA) in Bethesda, Maryland. (http://www.nature.com/news/calorie-restriction-

                falters-in-the-long-run-1.11297)

                 While in another study that started in 1989 and ended in 2009 for the National Primate Research Center (WNPRC) had shown that the calorie restriction did make a difference. The reason for this is, because they were given a poor diet. So the animals given a restriction only seemed healthier by comparison. This group was also given an unlimited amount which can have a profound effect.

                Overall the NIA group had better results because not only were all the monkeys’ on somewhat of a restricted diet but the sucrose in their diet was 3.9%, while at WNPRC monkeys’ diets contained 28.5% sucrose. The WNPRC was not given fish oil like the NIA and the WNPRC control group is heavier than the NIA control group.  While when researchers do calorie restrictions on mice they have a tendency of getting mixed results due to genetics, they believe this could have also been a contributing factor since the monkeys used in the NIA studies were from China and India while the monkeys’ used in the WNPRC studies were just from India.

                All in all it’s complicated to say in the least. As for humans studies have shown that those who are of average weight live longer. Personally, I will take my chances on the healthier diet because likeNir Barzilai, a gerontologist at Albert Einstein College of Medicine in New York, says that the centenarians he studies have led him to believe that genetics is more important than diet and lifestyle. “They’re a chubby bunch,” he says.As I partially agree with him I personally believe that if you watch what you put in your body and the type of calories that will help as well that the centenarians he studies have led him to believe that genetics is more important than diet and lifestyle. “They’re a chubby bunch,” he says. As I partially agree with him I personally believe that if you watch what you put in your body and the type of calories that will help as well

 

"Green" Nylons

            A group of researchers working at the Duke Cancer Institute found a very interesting discovery. They found a molecule that can be used in the production of nylon. What’s interesting is that they found said molecule whilst trying to find a cure for cancer. Since cancer changes the cells behavior and causes the cells to make varying amounts of products, they might be harvested for our use in the future.

            Nylon is one of the most used products in the world. We use it in carpentry, auto-motives, clothing, upholstery, and various other fields. Unfortunately, nylon is also one of the most resources intensive. It is made from the very common chemical known as adipic acid which comes from fossil fuels. However, “the pollution released from the refinement process is a leading contributor to global warming.”

            The researchers decided to look at adipic acid because of the similarities in cancer research and biochemical engineering. Since both of those fields are required to look at certain enzymes, it was basically by chance that they found this enzyme that can be used to make the right acid. “One of the most promising approaches being studied today for environmentally friendly adipic acid production uses a series of enzymes as an assembly line to convert cheap sugars into adipic acid” from these assembly lines, however, there was a very important enzyme that was missing. It is known as 2-hydroxyadipate dehydrogenase and is necessary for nylon production.

            In 2008 and 2009, they discovered a genetic mutation in brain tumors that changes the way an enzyme known as isocitrate dehygrogenase behaved. As a result, the group thought that the mutation could be used in another change that occurs in yeast and other bacterium. That enzyme is known as homisocitrate dehygrogenase and can be used to make the 2-hydroxyadipate dehydrogenase. After studying the behavior of these enzymes, they realized that “The functional mutation observed in cancer could be constructively applied to other closely related enzymes, creating a beneficial outcome.” That ourcome, of course, is the production of the 2-hydroxyadipate dehydrogenase enymze.

            Their original goal was to look at how cancerous tumors developed in hopes of finding a better way to make a treatment for patients. It’s fascinating how, as the lead researcher, Zachery J. Reitman,  put it, “As it turns out, a bit of information we learned in that process paves the way for a better method to produce nylon." Something so unexpected – better nylon production – coming from cancer cells? It’s just a hard thing to wrap ones head around. One of the professors in the Department of Pathology, Hai Yan, added this to their discovery, "This is the result of a cancer researcher thinking outside the box . . . Not only is this discovery exciting, it reaffirms the commitment we should be making to science and to encouraging young people to pursue science."

            Naturally, this discovery is only useable on a small scale. Being able to harness this information for a precursor to nylon production will be a huge task. It’s a task that should be taken further, however. With this new information, it’s another stepping stone in the right direction. Any direction that cuts down on pollutants should be taken further to help our planet as a whole for the people of today as well as the people of tomorrow.

http://www.sciencedaily.com/releases/2012/09/120923145102.htm

The Genes That Give Tabby Cats Their Stripe Patterns

Have you ever wondered how tabby cats get their stripes? Or why all cats don't have the same stripe patterns? Along a cat's nineteen pairs of chromosomes, there are genes, which make up the genome. Each breed of cat has its own dominant genes, and different genotypes and phenotypes that determine the pigments in its fur, the texture of its fur, the pattern of its fur, and there are different genes for cats that grow no fur at all. All cats have genes that affect the way they look, but one of the most distinct is the striped and blotched pattern look that tabby cats have in their fur. There have also been recent discoveries made in why all stripes are not created equal.

An example of how genes can affect the patterns in cat fur is a pattern known as Agouti. Some cats have different colored bands along the shafts of their tails, and the gene that causes this pattern is the “Agouti Signaling Protein,” and a mutation or change in this gene can have drastic affects on the pattern in a cat's fur. The banding is based on the dominance of the Agouti gene and occurs when a cat carries one or two copies of the gene. When the banded fur and solid fur alternate, it is called tabbying, which is common in many cats. If a cat has two copies of the non-agouti gene, then the fur will be solid. In most tabby cats, the stripes are defined and evenly spaced. There is also the tabby gene, as well, that affect the pattern. There are three different stripe patterns which are inherited through the tabby gene: Mackerel, Classic, and Abyssinian. A mutation in any of these genes can cause variations of those patterns.
In a recent study, there was a discovery of a mutation in the genomes in domestic tabbies which may even explain further into how cats get blotches instead of stripes. The gene mutation is called the “Taqpep mutation.” Researchers found that blotched tabbies had mutations in their copies of the gene, whereas striped tabbies had at least one copy with no mutation. Also, the mutated gene is one that blotched tabbies share with wild cheetahs whose fur went from spotted to striped. This mutation explains the pattern, but makes no distinction as to the color of the fur in cheetahs. A gene called the Edn3 decides the colors in the fur patterns.  

Tabby patterns only show up when cats begin to grow hair, which is within their first seven weeks of gestation, carried out while the embryo develops, by changing levels of Edn3. During gestation, levels of Taqpep increase. The Taqpep mutation happening earlier on in a cat's life may determine why spots and stripes don't change as the cat grows older. The main researcher in the study speculated that the gene has other functions, and may do more for the cats than simply change their patterns, such as helping boost immunity against disease and infections.


http://news.sciencemag.org/sciencenow/2012/09/how-the-tabby-got-its-blotches.html?ref=hp
http://www.nytimes.com/2012/09/25/science/the-gene-behind-cheetahs-spots-and-tabbies-stripes.html
http://news.discovery.com/animals/tabby-cat-stripes-gene-120921.html
http://www.livescience.com/23348-how-the-tabby-cat-got-its-stripes.html