Video: Epigenetics – Nature vs. Nurture in Cancer Research

Once nurture seemed clearly distinct from nature. Now it appears that our diets and lifestyles can change the expression of our genes. coque iphone 6 How? By influencing a network of chemical switches within our cells collectively known as the epigenome. This new understanding may lead us to potent new medical therapies. vente de coque iphone Epigenetic cancer therapy, for one, already seems to be yielding promising results. In biology, and specifically genetics, epigenetics is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence; it also can be used to describe the study of stable, long-term alterations in the transcriptional potential of a cell that are not necessarily heritable. Unlike simple genetics based on changes to the DNA sequence (the genotype), the changes in gene expression or cellular phenotype of epigenetics have other causes, thus use of the term epi- (Greek: επί- over, outside of, around) -genetics. The term also refers to the changes themselves: functionally relevant changes to the genome that do not involve a change in the nucleotide sequence. coqueiphone Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. coque iphone Gene expression can be controlled through the action of repressor proteins that attach to silencer regions of the DNA. coque iphone These epigenetic changes may last through cell divisions for the duration of the cell’s life, and may also last for multiple generations even though they do not involve changes in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organism’s genes to behave (or “express themselves”) differently. (There are objections to the use of the term epigenetic to describe chemical modification of histone, since it remains unclear whether or not histone modifications are heritable.) One example of an epigenetic change in eukaryotic biology is the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells. In other words, as a single fertilized egg cell – the zygote – continues to divide, the resulting daughter cells change into all the different cell types in an organism, including neurons, muscle cells, epithelium, endothelium of blood vessels, etc., by activating some genes while inhibiting the expression of others. In 2011, it was demonstrated that the methylation of mRNA plays a critical role in human energy homeostasis. The obesity-associated FTO gene is shown to be able to demethylate N6-methyladenosine in RNA.

33 Facts About Pollution That Are Gross

  1. Every year, the United States creates 11 billion tons of solid waste.
  2. The Environmental Protection Agency reports that the U.S. generates over 256 million tons of officially classified hazardous waste annually. This does not include toxic and hazardous waste that are not regulated or monitored by the EPA.
  3. Between 1950 and 1975, approximately 5 billion metric tons of highly poisonous chemicals were improperly disposed of in the U.S. It will cost between $370 billion and $1.7 trillion to clean up hazardous waste in the U.S. The EPA states there are at least 36,000 seriously contaminated sites in the U.S.
  4. Today, there are between 300 and 500 chemicals in the average person’s body that were not found in anyone’s body before 1920. Each year there are thousands of new chemicals sold or used in new products. There are more than 75,000 synthetic chemicals on the market today.
  5. Factories in the United States discharge approximately 3 million tons of toxic chemicals into the water, air, and land annually.  Each year 1.2 trillion gallons of untreated sewage, storm water, and industrial waste are dumped into U.S. waters.
  6. A 2010 study found that children in families who live near freeways are twice as likely to have autism as kids who live farther away from freeways. Scientists believe the increased risk is due to exposure to pollutants given off by freeway traffic.
  7. Concentrations of two common pollutants, PFOA (perfluorooctanoic acid) and PFOSA (perfluorooctanesulfonic acid), which can be found in nonstick cookware and stain-repellant fabrics, can impair immunity in children. They can also prevent vaccines from triggering sufficient quantities of protective antibodies.
  8. Americans make up an estimated 5% of the world’s population. However, the U.S. produces an estimated 30% of the world’s waste and uses 25% of the world’s resources.
  9. The world’s largest polluter is the U.S. Department of Defense, producing more hazardous waste than the five largest U.S. chemical companies combined.
  10. The Mississippi River carries an estimated 1.5 million metric tons of nitrogen pollution into the Gulf of Mexico each year, creating a “dead zone” in the Gulf each summer about the size of New Jersey.o
  11. Approximately 46% of the lakes in America are too polluted for fishing, aquatic life, or swimming.
  12. Americans buy over 29 million bottles of water every year. Making all those bottles uses 17 million barrels of crude oil annually, which would be enough fuel to keep 1 million cars on the road for one year. Only 13% of those bottles are recycled. Plastic bottles take centuries to decompose—and if they are burned, they release toxic byproducts such as chlorine gas and ash containing heavy metals.g
  13. Fourteen billion pounds of garbage, mostly plastic, is dumped into the ocean every year.
  14. Over 1 million seabirds are killed by plastic waste per year. Over 100,000 sea mammals and countless fish are killed per year due to pollution.
  15. More oil is seeped into the ocean each year as a result of leaking cars and other non-point sources than was spilled by the Exxon Valdez.
  16. Polluted coastal water costs the global economy $12.8 billion a year in death and disease.
  17. Scientists report that carbon dioxide emissions are decreasing the pH of the oceans and, in essence, acidifying them.
  18. An estimated 1,000 children in India die every day due to disease caused by polluted water.
  19. Approximately 1/3 of male fish in British rivers are in the process of changing sex due to pollution. Hormones in human sewage, including those produced by the female contraceptive pill, are thought to be the main cause.
  20. Pollution in China alters the weather in the United States. It takes just five days for the jet stream to carry heavy air pollution from China to the U.S. Once in the atmosphere over the U.S., the pollution stops clouds from producing rain and snow—i.e., more pollution equals less precipitation.
  21. Though Botswana has only 2 million people, it is the second most polluted nation in the world. Pollution from the mineral industry and wild fires are the main causes.
  22. Nigeria is the most populous country in Africa and the eighth most populous in the world, with over 155 million people. It is also Africa’s largest oil producer, accounting for 2.3 million barrels of crude oil a day. However, the UN recently declared that 50 years of oil pollution in the Ogoniland would require the world’s largest and biggest oil cleanup.
  23. The world’s largest heavy metal smelting complex is in the Siberian city of Norilsk. Human life expectancy there is 10 years lower than in other Russian cities.
  24. Between 1930 and 1998, nearly 300,000 tons of chemical waste was improperly disposed of in Dzershinsk, Russia, a Cold War chemicals manufacturing site. Toxic levels are 17 million times the safe limit. In 2003, the death rate of the city exceeded the birth rate by 260%.
  25. Lake Karachay, located in the southern Ural Mountains in Russia, is considered to be the most polluted spot on earth after it was used for decades as a dumping site for nuclear waste. Spending just 5 minutes near the lake unprotected can kill a person. In the 1960s, the lake dried out and radioactive dust carried by the wind irradiated half a million people with radiation equivalent to the atomic bomb dropped on Hiroshima.
  26. In Rudnaya Pristan, Russia, lead contamination has resulted in child blood levels eight to 20 times higher than allowable U.S. levels.  Children in Kabwe, Zambia have some of highest blood levels of lead in the world
  27. In Kabwe, Zambia, child blood levels of lead are five to 10 times higher than the allowable EPA maximum.
  28. The largest e-waste site on earth is in Guiyu, China. Approximately 88% of children there have dangerous levels of lead in their blood.
  29. The world’s largest CO2 emitter is China. China emits more CO2 than the U.S.  and Canada combined, up by 171% since 2000. The U.S. Department of Defense is the world’s largest polluter
  30. Over 80% of items buried in landfills could be recycled instead.
  31. For 1.1.billion people around the world, clean water in unobtainable. Almost half of the world’s population does not have proper water treatment.
  32. The average office employee throws away 360 pounds of recyclable paper each year.
  33. Antarctica is the cleanest place on Earth and is protected by strong antipollution laws.

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