Tomatosphere and Epigenetics

Have you heard of Tomatosphere™? This is a really cool program operated in Canada through Let’s Talk Science. It is a free program offered to students from Kindergarten to Grade 12, where these students can study the effects of “space” on the germination of tomato seeds. Participating classes receive two packages of tomato seeds: one is a package of seeds from tomatoes that were sent into space or treated to space-simulation conditions, i.e., the experimental group; the second package contains seeds that spent time on plain old Earth, i.e., the control group. Students the study the germination of these two groups of seeds, expanding on the basic experiment depending on curriculum and grade level.

As a scientist and a gardener, I am in LOVE with this program. But I have a question for Tomatosphere™: I want to know if anyone is looking at the possibility of EPIGENETIC changes to the tomatoes. This begs the next question: what is epigenetics? That’s the question I am hoping to answer for you today.

Tomatospher Question

My tweet to Tomatosphere

 

To begin our understanding of epigenetics, let’s do a quick review of the central dogma of genetics and inheritance. The traits that make us a human (or a gorilla, or a tomato plant) are coded in our DNA. To express the trait, the DNA is transcribed into messenger RNA (mRNA), which is in turn translated into amino acids that are then put together to build the necessary proteins for each trait. We inherit these genes from our biological parents: one gene from the egg and one gene from the sperm. The trait that is expressed is the dominant gene. Differences in expression generally mean differences in the genes, or the specific DNA code.

For example, let’s look at blood types. Let’s say you inherit the “A gene” from your dad and the “O gene” from your mum. Your genotype will be AO. But since the A gene is dominant, you will only express this gene and you will have blood type A. This is called your phenotype. To change your blood type, you would need to change your genotype. That is the basics of inheritance.

Epigenetics throws a wrench into this understanding of genetics and inheritance. Epigenetics means “outside genetics”, and refers to changes in gene expression that are not a result of physical changes to the DNA sequence. In other words, changing our phenotype without changing our genotype. Epigenetic marks control the expression of genes, which ones are turned on, when, and how much. One of the most interesting things about epigenetics is that we can start to see how the environment plays a role in gene expression. Our lifestyles, our preferences, our exposures to certain environmental factors can all contribute to variations in how the same gene can be expressed across individuals. What’s more, is that it has been discovered that these changes in epigenetics can be inherited. What this means is that if you exposed to something in your environment that causes a change in how a gene in your DNA is expressed, this change could be passed on to your child, and even to your grandchild. This is referred to as transgenerational epigenetics. It is an emerging area of research and the exact mechanisms of how this works is being widely studied.

This brings us back to Tomatosphere™ and my question. In the experiment we have tomato seeds that were exposed to space conditions. These conditions may not have changed the gene sequence, the genotype, of the tomato, but they may have caused epigenetic changes. It has been shown that changes in the gene that controls ripening in tomatoes is impacted by epigenetics, so do we see changes in other factors with these space tomatoes? AND, what about the progeny? Do the tomato plants grown from the seeds of the space tomatoes also show epigenetic changes?

Epigenetic tomato experiment

A sketch of my proposed Tomatosphere experiment.

 

For more information on transgenerational epigenetics, check out this Nature article.  I also recommend the website What is Epigenetics for a more detailed description of epigenetics.

 

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The Truth About Vaccines

Here at Curiosity Science, we are big fans of vaccination. It is one of the simplest things that you can do to improve your health and it is the way that we will cure diseases. The fact that smallpx no longer threatens us is the best example of how vaccination cures and eradicates diseases. That is, afterall, the goal of modern medical research: to cure and eradicate diseases.  However, in recent years, vaccination has come under fire from an anti-vaccine movement.

The anti-vaccination movement is an example of a poor understanding of science mixed with fear mongering. As I said, we here at Curiosity Science are all about vaccines and vaccination. The science is sound. To quote Neil Degrasse Tyson: “The good thing about science is it is true whether or not you believe in it.”

Now, that being said, Curiosity Science is also a welcoming place to anyone who has vaccine concerns. One of my biggest concerns has been how frustrated us on the pro-vax side have become that we are almost jerks to anyone who questions vaccines or vaccine safety. I get that. Believe me I have been there-it is especially frustrating when you see otherwise intelligent people fall victim to erroneous internet fear articles that come from seemingly legit websites like http://vactruth.com/. This information is not cultivated by experts in the field; it is cultivated by a man who fears that vaccines are somehow to blame for his kid “not meeting the developmental milestones”.

Why is this a concern? Well because people are making jumps that are not proper conclusions by reading a list of ingredients in vaccines and thinking they are somehow nefarious. The problem being that most people don’t have enough chemistry to understand what those crazy “chemically sounding” ingredient names mean. That is why you want to talk to experts about those things. You wouldn’t take surgery advice from someone who isn’t a surgeon right?

This is why I want to emphasise that here at Curiosity Science we are friendly and open to all concerns about vaccines. If you want actual, scientifically verified information, please look here. If you want to talk to an immunologist or a pathobiologist or a pharmaceutical chemist, send us an email at thecuriosityscience@gmail.com. It is ok to have questions and concerns. I also encourage all of you who are trying to change the minds of anti-vaxxers to do your best to create a friendly, open dialogue. Making people feel stupid (no matter how frustrated you get) is never going to be a winning strategy.

For those of you who are concerned about vaccines check out this awesome comic. There is no conspiracy; only a plea to make our population as healthy as possible! Vaccinate yourself against misinformation and know your experts.

Vaccines copy

What’s in a Blood Type?

Have you ever wondered about your blood? What makes type A different from type B? Maybe you are a blood donor and are curious why your blood type is different than your parents or siblings?

What determines the blood type is proteins found on blood cells called antigens. The antigens that are most commonly used to type blood are called type A, type B, and the Rhesus factor. If you have the A antigens, then your are blood type A. If you have the B antigens, then you are blood type B. If you have both A and B antigens, then you are blood type AB. If you lack these antigens completely (i.e., you have neither A or B antigens) then you are blood type O. The Rhesus factor is classified as to whether you have that protein (positive) or you lack the Rhesus protein (negative). Putting this all together, someone with a A antigens and the Rhesus factor would therefore have blood type A+. Someone with ALL of these antigens, A, B, and Rh, would be blood type AB+ and someone who lacks all of these antigens would be blood type O-.

Now, these antigens don’t really make a difference to your health, anymore than the colour of your eyes or hair. They will, however, make a difference if you receive a blood product, say for a surgery or something. You can only receive blood that is compatible with your blood type. To be compatible, the blood you receive must not contain any antigens that you don’t already posses. This is because the presence of foreign proteins will cause an immune reaction, which produces immune proteins called antibodies. The blood type O- has no antigens and therefore can donate to ALL blood types. This blood type is called the universal donor and that is why it is in most demand. The blood type AB+ has all anitgens and therefore won’t raise an immune response to any of the blood types and is called the universal receiver. Canadian Blood Services has a wonderful explanation of the different blood types, who they can donate to and receive from on their website.

For me what makes blood types really interesting is when you start looking at blood components. Blood is largely made up of plasma, red blood cells, white blood cells, and platelets. Red blood cells transport oxygen to the body tissues; white blood cells are immune cells, platelets are cells that are used in clotting, and plasma is the liquid part, that contains the proteins and nutrients in the blood that are required by the tissues in the body. Plasma alone can be used to help individuals with bleeding disorders, liver diseases, and cancers. It can also be used in the production of vaccines or other pharmaceutical products, such as immune globulin used to treat tetanus infections. What is really cool about plasma is that the most in demand blood type for plasma donation is AB+. This is because it is the universal PLASMA donor.

blood donation 45 copy

This might be surprising since above I wrote it is the universal receiver. For whole blood (blood that contains all of the cells and plasma) it is the universal receiver. But once we remove the cells with the antigens leaving only the liquid plasma, it becomes the universal donor. Any antibodies that are present in the blood will be in the plasma, and we know that AB+ won’t form antibodies to any of the blood antigens because it has all three. This means that there will be no antibodies in the plasma that could cause a problem. What is a problem though is that AB+ is the second rarest blood type. Only 2.5% of the population has this blood type. (The rarest blood type is AB- with 0.5% of the population having this type.) I happen to be one of these people, which I have always thought was really cool. The picture on the right is me at my 45th blood donation with Canadian Blood Services.

If you can donate blood, whole or plasma, please do. Not only does it save lives, but it is pretty cool science.