Having Twins is in Your Genes

For a while, scientists have known that it was highly likely to give birth to twins being a twin themselves, but nobody really knew why.  After conducting studies and collecting data from over 2,000 woman who gave birth to fraternal twins, a number of researchers from multiple countries collectively found two different genes that increased the likelihood of having twins.  Scientists searched for what are called single nucleotide polymorphisms, or SNPs.  The first one they found was linked to a hormone that regulates the release of eggs from the ovaries.  If levels are too high, multiple eggs could be released, resulting in the birth of fraternal twins or other multiple births.  The second gene found, which is still somewhat of a mystery, relates how the ovaries respond to the hormone that regulates egg release.  Not much is known about the gene, but researchers believe it could relate to why some mothers respond better to in vitro fertilization.  I find this type of research fascinating since I am a twin myself.  Knowing that there is another set of twins in my family always made me wonder if it really is true that having twins is linked to genetics, so finding this article was reassuring.

http://www.sciencemag.org/news/2016/04/having-fraternal-twins-your-genes-and-your-hormones

Picky Eating May Stem From Your Genes

Researchers in the UK and Norway recently published a study in the Journal of Child Psychology and Psychiatry that focused on the genetics behind picky eaters. The study centered around 16 month old twins from a UK program called Gemini. Over 1900 families with twins participated in the study, curious to know whether or not their children's eating habits were affected by their genetic makeup. The researchers compared identical twins, due to the fact that they share 100% of their genes, and fraternal twins, who share approximately 50% of their genes. The parents were required to take a survey that asked a list of questions pertaining to their child's eating habits and patterns, as well as what the children enjoyed eating and what they resisted eating. The results showed that at least 46% of variation in the fussiness of a child came from their genetic makeup, influenced by multiple genes and not just one singular one. The finding also showed that 58% of new food rejection in 16 month old children stemmed from their genetics as well.

The main conclusion to this study was that genetics definitely has an influence in the food pickiness of a child, however, the exact extent and the specific genes that contribute to this have yet to be identified. The researchers proposed the idea that while genes have a huge influence on this topic, they are not set in stone when it comes to what the child eats, or how they develop in the future. In most cases, the child's environment has an equally important role in what kinds of foods they like and dislike. Depending on factors such as location, food availability, and parental influence, children may change over time in their level of food pickiness despite the initial influence that their genes have on them. A significant factor of the study was that it was performed on toddlers, a time where development is still a major factor and change may occur. In adult populations, the results may be different. It would be interesting to see a follow up study for these 16 month old children at different stages in their lives to assess how much has changed since their initial assessment. This information poses an important question based on the foundation of our genes: just how much do they influence our likes and dislikes when it comes to food? And to what extent will our likes and dislikes be passed down to our children? I believe this study is important because with more research and future findings, we may be able to pinpoint the exact genes that are responsible for influencing our taste. This study opened the doors for much more research to be done in the field.

Link: https://www.theguardian.com/science/2016/oct/14/is-your-child-a-fussy-eater-the-reason-could-be-in-their-genes 

Gene to Increase Chances of Twins

After a study of 2000 mothers of fraternal twins, researchers have discovered that a woman's chance of having twins would increase if they have at least one of two genes through looking at their gene sequences. One gene affects the amount of hormone levels the mother has and the other is how the ovaries respond to them. Having just one copy of the SNPS would increase the chance of having fraternal twins by 29%. These SNPS are called FHB and SMAD3. FHB is the one that affects hormone levels and SMAD3 affects the ovaries response to FHB.

With this new information researches now have a better understanding of exactly what causes twins. This gives support that if the there are fraternal twins on the mother's side of the family, then there is a higher chance of her giving birth to a set of twins as well. Simply having the gene for twins does not necessarily mean the mother will give birth to twins, it only increases the likelihood. These genes in fact do not have to be present at all. So, there could be an "eve" gene for having twins, but it may have not been needed for the first set of fraternal twins to exist.

Closer Links to the Genetics of Fraternal Twins

The chance of having fraternal twins has long been known to increase if relatives have also had the  event occur, however researchers have recently been underway to find a closer link to the explanation. The United States alone saw a 76% increase in the fraternal twin population from 1980 to 2011, and scientists want an answer.

This article explains the path scientists have taken to identify the increasing factor. They've collected and compared single nucleotide polymorphisms (SNPs) of 2000 mothers of fraternal twins to SNPs of mothers who had not had twins. Researchers narrowed the results down to find two SNPs that increase a woman's likelihood of having fraternal twins by about 30%!

One of the SNPs is known to cause an increase in the hormone involved in the production of follicles, which are the sites within the ovaries that house and mature the eggs before they are released from the ovary. If the levels of this hormone is too high, the mother has an increased chance of releasing multiple eggs.

The second SNP is a bit more complicated. This one in particular is a gene that alters the way molecules signal to each other. This gene in turn, called SMAD3, has an affect on the way that the ovaries respond to the hormone coded by the other SNP. This same gene has also been linked to osteoarthritis. Scientists are planning to conduct further research on how mothers react differently due to the SMAD3 gene. These results presented were only the first step.

It's really awesome that this group of scientists have made such progress on identifying the genetic components behind having fraternal twins. This is the closest that scientists have yet to come in relation to this subject matter. This is not exactly the most critical research to be done, as there usually aren't complications or anything wrong with birthing fraternal twins. However its still always great to hear about the evolution of genetic findings in all aspects of life.

Why Do Mosquitoes Prefer Your Blood Over Others?

Ever wonder why mosquitoes bite you and not your friend sitting next to you? A recent study that was published in the journal PLOS ONE addressed this mystery.The study tested the level of attraction that mosquitoes had towards fraternal and identical twins. The  female species of mosquitoes involved in this study were Aedes aegypti which are the main transmitters of the yellow fever virus, and the dengue virus. Female mosquitoes bite humans because they need protein from the blood to produce their offspring. Once the female obtains a sufficient meal of blood, she rests until her eggs develop and then goes on a quest in search for a new host. Male mosquitoes do not feed off of human blood; they depend on the sugars from flower nectar as their food source. Typically, female mosquitoes have a preference for certain individuals with a distinct smell since they can detect strong chemicals emitted by the human body. Since body odor can be genetically controlled, Logan and his colleagues decided to  examine whether or not there are certain genes responsible for the attraction of mosquitoes. To determine if the attractiveness to mosquitoes has heritable factors, the fraternal and identical twins hands were placed in a Y-shaped olfactometer. In each trail, a new set of mosquitoes were used and their response to the body odors from the hands of each twin was measured. The results from the experiment demonstrated that mosquitoes can detect a genetic difference through odors when selecting a host. However, it is still unknown whether the differences among monozygotic and dizygotic twins is due to the presence or absence of attractive and repellent chemicals. Even though they were unable to decipher what exact genetic components are responsible for attracting mosquitoes, they are one step closer in identifying the genes that influences attractiveness.

In my opinion, the genetic research being conducted on mosquitoes has many benefits in helping eliminate the transmission of malaria, yellow fever, and other dangerous viruses, If researchers can determine which genes that are responsible for the attractiveness of mosquitoes; then that valuable information can be used to design better strategies in protecting the people. Additionally, company's can develop stronger and more efficient repellents that contain a certain chemical formula based off the genetic findings in research.

Do Mosquitos Love You? Blame Your Genes

Ever wonder why you are the only one ever being eaten up by mosquitos while others don't? Why are these mosquitos circling you but not the person next to you? In a recent study, researchers found that mosquitos are attracted to body odors, which are influenced by your genetic make up.

The study consisted of 8 pairs of female identical twins and 19 pairs of female fraternal twins. They found that expert sniffers were able to match the scents to the identical twins and then tested the identical and fraternal twins to see which were more attractive to the mosquitoes.The research revealed that the participants' attractiveness to mosquitoes was more similar in identical twins than the fraternal twins, hence the idea that your genetic makeup influences the odor that attracts mosquitoes.
Much more research must be done to further prove the idea. This type of research is extremely important because this could help fight against mosquito transmitted diseases like Malaria, West Nile Virus, Elephantiasis, Dengue Fever, and Yellow Fever.
I personally believe more research should be done because the repellents that we use for the mosquitos in the long run will start hurting humans. Mosquitos are evolving more and more and are beginning to be immune to the repellents, meaning we have to make stronger ones ver time. The stronger the repellent odors, the more harmful on humans.

Original Article

Beauty or Beast? Why Perceptions of Attractiveness Vary

A new study published in the Journal of Current Biology suggest that ones perception of other people's attractiveness is mainly the result of ones experiences. In the study conducted with twin, the researchers found that a person's environment plays a bigger role than gene in shaping who they find attractive.
The study consisted of 547 sets of identical twins and 214 sets of fraternal twins. The participants looked at 98 male faces and 102 female faces and participants rated them based on who was most attractive. The researchers compared the results between identical twins and fraternal twins to see if genetics played a major role in the attractiveness of the person or if it could be because of the environment the person was exposed to. The researchers concluded that genetics only attributed to the attractiveness of the person 22% of the time while the environment the person is exposed to attributed to the attractiveness of the person 78% of the time.
I believe this was kind of a fun experiment to prove that beauty is truly in the eye of the beholder. That the experiences people have and the knowledge one may have attracts some more than others and it is not always about the looks.

Original Article

Summer Bites

Summer is just around the corner and most of us cannot wait! All that awaits us is days of sun, sand, and fun! But as you lay there enjoy the setting sun something bites you. With summer comes those pesky bugs and one of those bugs are mosquitoes. Your genes may affect whether or not mosquitoes want to bite you or someone else.

In a new study, a group of researcher from London did an experiment on identical and fraternal twins. They discovered that genes actually do influence whether a mosquitoes are attracted to you or not. The genes that are responsible for this natural deterrent are the genes in control of body odor. Th people who mosquitoes find less attractive have basically a natural repellent. These natural replants are control strictly by genetics.

During the study a team studied eighteen identical twins and nineteen fraternal female twins. The result were that the identical twins were more similar in their appeal to mosquitoes than the fraternal twins were. The data collected from this experiment can be used to help us to prevent bites and can help stop the spread of diseases through bites. The lead researcher stated that he thinks one day in the future people could a pill which could enhance the production of natural repellents.

Everyone always has that one friend that just attracts all the mosquitoes and now there is a reason why. This study could help stop the spread of diseases like malaria.

Attention Deficit Hyperactivity Disorder Epidemic

      

Attention Deficit Hyperactivity Disorder

                 A.D.H.D. medications were in short supply from the fall of 2011 to the spring of 2012 throughout the United States. This shortage was due to the supply being outpaced by the request for the medication. Prior to the 1990’s, less than 5% of school-aged children were thought to have Attention Deficit Hyperactivity Disorder. According to the Centers of Disease Control and Prevention, 11% of adolescences from the ages of 4 to 17 had received the news that they had A.D.H.D.; this 11% does not include the adult population. This shows that the number of children diagnosed with A.D.H.D has skyrocketed over the past 20 years.

A.D.H.D. Medications

                For many years people felt that A.D.H.D. was a made up disorder. Yet, facts have shown that A.D.H.D. is a genetic based disease. The way that scientist determine if specific behaviors and traits are genetically based are by comparing twins. Identical twins share almost 100% of the same genes, while fraternal twins share about half of their genes. This shows that if a disorder is genetically based, the identical twins have a higher chance of sharing it than the fraternal twins. Researchers at Michigan State University, in 2010, studied 22 different twins and established that the traits of hyperactivity and inattentiveness are greatly inheritable. Also, studies that use brain-imaging, display dissimilarities between people who were diagnosed with A.D.H.D. and people who were not. These images show that people with A.D.H.D. have less receptors for chemical messenger dopamine in specific regions. This would cause the brain to not function to its highest abilities.

Brain Imaging of Non-ADHD and ADHD patients.

 

            Since so many children and adults are diagnosed with A.D.H.D. the increase in medications has raised. New medications are being produced and more medications are being distributed. The genetic disorder A.D.H.D. affects the lives of many people, especially children. Now knowing about this disease had opened up the door to improvement for it. Children are now receiving the assistance that they need to become focused and do well in school. There are therapists for them to talk to, there is access to tutors, and time modifications for standardized testing. Also, there is a drug treatment for this disease. People are beginning to realize that this is not a disease that is just made up and people do suffer from this. It really makes a difference to do the studies and find out where this disease comes from and how you can resolve the problem.

             To me many children do have A.D.H.D. and they need for it to be taken care of. It distracts them from the things that they need to do and accomplish in life. It can be the difference if they do good in school and obtain and retain an education. Knowing the it is a genetic disease does help figure out how they can fix the problem and make medication to fix the problem. I do believe that people do abuse the used of A.D.H.D. medications and that does need to be looked into. Though many people are diagnosed with A.D.H.D. I do not feel that they all have the disease.  

http://www.nytimes.com/2013/10/20/magazine/the-not-so-hidden-cause-behind-the-adhd-epidemic.html?_r=0

http://psychcentral.com/lib/the-genetics-of-adhd/0003789