PROTECTION FROM UV RAYS By Tejas Kelkar There are 3 major types of UV light, UVA, and UVB, and UVC • UVA is detectable by cells and is just above the visible spectrum. • UVB has a shorter wavelength, is can damage cells, and is really hard to detect. • UVC is rarer, has a much shorter wavelength, and is germicidal. Which means it is really dangerous. Name+ Abbreviation Wavelength Ultraviolet A / UVA 400-315 nm Ultraviolet B / UVB 315-280 nm Ultraviolet C / UVC 280-100 nm When there is no UV rays, people with lighter skin have at most a miniscule amount of melanin. Photosensors on cells in the lower epidermis sense UVA and tell melanosomes to produce melanin. They produce melanin, which surrounds the nucleus and protects it from radiation. While the melanin accumulates, there is always a chance that DNA gets mutated But there is one issue to this system: the photosensors cannot detect the more harmful UVB and UVC as well. Because of this, if there is a lot of UVB and UVC light present but not a lot of UVA, melanin may not build up, causing major health issues. People with darker skin have a large amount of melanin production anyway. Because of that, even if there is UVB and UVC radiation, the cell won't be as affected. If it sees UVA, it will release melanin like normal. This is a much better defense against ultraviolet radiation. As UVB and UVC hit the cell’s photosensors, they don’t respond, but when it tries to pass through the nucleus, the melanin prevents it. When UVA radiation hits the cell’s photosensors, it acts like a normal cell, only more prepared. Random Fact 3.5 million people are DOCUMENTED each year getting skin cancer. That means they are most likely other cases in places where there isn’t knowledge of skin cancer Therefore, these two devices Device that increases melanosome amounts in cells Device that increases melanosome activity The Gene The Gene that controls it is called the Ocular Albinism type 1 gene (OA1), and it controls the production in two places. It controls the number of melanosomes produced and the melanosomes’ activity. The gene should be altered to produce twice the amount of melanosome before stopping, and telling the melanosomes to produce more. Increasing this protein increases melanosome activity OA1 Gene ProteinRab7 and Rab27a Controls melanosome activity ProtienCystinosin Controls melanosome production Decreasing this protein increases melanosome production But the melanin still lets in 0.5% of the UV radiation, at least This means 17,500 people will still get skin cancer each year So how could you reduce that number? The spores of certain types of Bacillus bacteria (such as anthrax) can survive up to UVC radiation. If bacillus bacteria on your skin are given DNA instructions to form dormant spores that don’t respond to growing conditions, you could give yourself a transparent ultraviolet protector. The disadvantage of this is that if the spores are kept dormant, there wont be more bacteria, and spore production will stop. Device for bacillus skin bacteria to form dormant spores The Gene No one really understands how the genes for this work, other than that fact that it works. The idea behind it is it surrounds the DNA with stuff to absorb the radiation, similar to melanin. The aim is to make the bacteria stay this way. It would look something like this Diagram of the devices working together Key Altered Bacillus Dormant Spore Melanosome Cell DNA+Nucleus with the melanin coat The bacterial spores block most of the UV rays, and the melanin in cells deals with UV that passes by the spores How to keep the spores growing The issue with this is that if the bacterial spores don’t grow, the bacteria producing the spores will die out, and then the spore production stops. So instead, they should be instructed just to find the cold months good for growing. When the sunlight hits the bacteria directly, with a lot of UV radiation (such as summer), the bacteria spores will stop growing. When the sunlight does not hit the bacteria directly, with a lot less UV radiation (winter), the spores will grow into bacteria. Since the bacteria spores need to grow sometime, the winter is best for them, with 30-60% less UV radiation. But then you are defenseless against the other 40% (unless you naturally have dark skin). This is why you need both. One as your summer defense, one as your winter defense. Possible Issues This method of ultraviolet protection would be costly. There isn’t a way to produce the right kind of bacillus that is safe for us (most of the workable bacteria are anthrax related), and putting the bacteria into producing dormant spores then they have good conditions to grow would be really difficult. Solutions for Possible Issues • To produce the right kind of bacillus that is safe for us, we would need to change its genes to make it dependent on us, and get rid of any genes that could possibly hurt us. Either that or we could transfer the genes that make anthrax spores UV resistant into a safer bacteria • To have the bacteria producing dormant spores, we would have to instruct the bacteria so that they think that the normal environment is not normal. This would cause them to stay as spores. • To keep bacteria creation going, it could be made so the spores find the environment perfect in the fall (spring in the southern hemisphere) and grow, but in the other season they find the environment bad, and stop growing.