Fruit Fly Gene Used to Detoxify Land

Recently, scientists at the University of York have discovered another use of a gene found in common fruit flies. This gene, found in the common fruit fly, Drosophila melanogaster, can be successfully expressed in a plant, and thus used to detoxify land contaminated with TNT. The plant specifically that this gene was tested on was Arabidopsis, a member of the cabbage family. Plants given the ability to express this gene were found to be more resistant to TNT and were better able to remove it from contaminated soil than wild-type plants without the gene.

The gene found in fruit flies, glutathione transferase, DmGSTE6, contains an enzyme that attaches to the TNT molecule itself and has the ability to make it less toxic through modification; making it less toxic to the environment in general, not just the plant. Trinitrotoluene, more commonly referred to as TNT, is an explosive that has been manufactured and used in waste sites, mines and war zones. Any remnant of TNT resists being broken down by microbes and remains in the soil for decades. It then lingers in the roots of plants, and inhibits its growth, as well as its development.

Given the inability of TNT to breakdown, the most important factor of this gene could be that the transformation through the expression in Arabidopsis assists TNT into converting into a product that may be more easily broken down in the environment. There are sites dating back as far as World War II that are still affected by TNT in the area, indicating that something needs to be done and needs to be done quickly. Explosive remnants in the environment are not only a danger to plant and animal life, but a threat to human health as well.

I found this article to be extremely interesting for a multitude of reasons. I always think it is fascinating to see the scientific chain reaction of something that happened so many years ago. I also am curious to see the future of genetic engineering and just how far we will be able to use these techniques. With how far we've already come, I have no doubt that we will be able to improve and modify many problems in the environment.

Birds Can Be Drawn to the Scent of Plastic

Seabirds typically feed on krill- small crustaceans at the surface of the ocean- but over the last half century or so, they have also been feeding on small bits of plastic (microplastics) that comes from trash that has been broken from exposure to UV radiation and waves. Theories have been made as to why marine animals eat plastic. Some theorized that they mistake it for food because of its small appearance, but two scientists from the University of California, Davis released a study that said otherwise. 

Many people think the birds are stupid and can't differentiate between plastic and their normal food, but Matthew S. Savoca, the paper's lead author, says that these people don't take into consideration that these birds have been trained over hundreds of thousands of years to find tiny pieces of food in the ocean. Gabrielle A. Nevitt, a professor and author of the paper, has been studying seabirds for years. She has found that these birds have a very strong sense of smell and respond to the chemical dimethyl sulfide to find their prey. This chemical is released by phytoplankton as it gets eaten by a predator or breaks down in the ocean or on shore, which signals to the birds to come eat the predator, typically krill or a relative of krill. The two scientists found that this chemical is also released when microplastics are present in the ocean. 

In their study, the scientists used plastic beads that were four to six millimeters in diameter and made of the same plastic used in bottles, bags, textiles, and other objects. After the beads had been in the water for three weeks, dimethyl sulfide was found in the water and air. The birds are using their evolutionary traits and abilities to forage in ways that is harmful to them and is causing obstruction and toxicity. The study claims that by 2050, 99% of all seabird species will have eaten plastic debris. Dr. Nevitt says that the study may have implications for marine animals besides birds, such as baleen whales who eat similar species to the birds, or sea turtles who are also attracted to dimethyl sulfide.  Mr. Savoca said that fifty years ago there was no plastic in the ocean, and now there are hundreds of millions of tons. This number is staggering, and it is scary to know that it will only continue to grow. Humans are changing the world extremely quickly and it is harming the other species that also occupy our planet. The problem with plastic in our ocean is one that may not be able to be solved and eliminated, but it can be slowed down if people are made more aware of what our waste is doing to animals. We unknowingly contribute to the pollution of our oceans every day, even by using products that contain microplastics, so education is the best possible solution to this problem.

How the Brown Rat Conquered New York City

The brown rat has managed to populate New York city by the millions, with billions more in other cities across the world. They contaminate crops and food supplied and destroy wires, walls, and cars, while spreading bacteria and disease. However, scientists are not entirely sure as to how Rattus norvegicus became so rampant. Dr. Munshi-South and colleagues finished a study of brown rats that began to answer the question of what is a New York city rat and where did it come from? They found that these rats began spreading slowly for thousands of years, but in the past three centuries they spread much more rapidly. Dr. Munshi-South contacted researchers from around the world and obtained DNA from hundreds of brown rats, from Japan, New Zealand, Brazil, and the Galapagos Islands to name a few,  to compare to that of the rats of NYC. The study revealed that brown rats originated in northern China or Mongolia and fed on wild plants and small animals, until farming in China began, during which rats found a reliable food supply and moved from open plains to farms and villages. The rats then began to expand to other parts of Asia, and eventually west to Europe. It is these rats that are the ancestors of the inhabitants of New York today. As European countries colonized the Western world, they took the rats with them.

Dr. Munshi-South thought that he would find that New York's rats have a mix of genes from ancestors from all over the world, but he found little evidence of genetic mixing in New York or any other city. It seemed that there was not many migrants that arrived and reproduced after a city was already populated with rats. This could be because brown rats are territorial and simply mean, as noted by missing eyes and scars observed by Dr. Mushi-South in many rats. The theory is that the first rats to arrive in a city reproduce rather quickly, so when new rats come along, they are no match for the residents that have already inhabited the city. This is a good thing because it is unlikely that new diseases on new rats can come into a city that is already populated with rats.
Based on the results of the study, I think that we should not take action to eliminate brown rats. Although they do spread bacteria and destroy wires and walls, they are keeping out lots of potential disease because of their territorial nature.

Royal Bones Found in Parking Lot

Two years ago an old skeleton was found under a parking lot in Leicester England. The archaeologists who found the skeleton claimed they found the bones of Richard III, a 15th century monarch. This claim was based on the fact that the skeleton was male, the right age, had battle injuries, and scoliosis. The scientists couldn't be entirely sure it was him so of course DNA evidence was needed.

Image from http://www.thetimes.co.uk/tto/multimedia/archive/00380/RichardIII_380709a.jpg

Today, December 2nd, it was announced that the DNA analysis of the skeleton was completed. It was reported in Nature Communications. The DNA analysis proved that they bones did belong to the former king. The scientists were able to trace the genetic evidence through more than 20 generations of the dead King's family tree to his living descendants. This means that the oldest DNA identification case of known individual was completed.  Turi King, the lead geneticist who lead the analysis stated that they were even 99.999% sure that the remains belong to Richard III.
What the team did was scrape together a DNA profile from a very old skeleton. Since the DNA was so old and damaged, scientists had to look through millions of ribbons of splintered DNA strings. Also to make sure the analysis wasn't contaminated, scientists did the sequencing in multiple clean rooms at multiple locations. Then the profile was compared to Richard III's living relatives. That was still difficult though because an ancestor from 20 generations back would only contribute .000001 of an individual's DNA. What does go almost unchanged through generations is mitochondrial DNA and the DNA on the Y chromosome. Mitochondrial DNA only comes from the mother allowing scientists to look at an all female line through the family tree. It was discovered that the descendants had the exact same mitochondrial DNA except for 1 single mutation. Richard did not have a pure male-line descendants making the tracking of the Y chromosome difficult. The team had more than enough information though.
I thought this was extremely interesting and relevant to class because we were looking at case studies similar to this with mummies and learning about how difficult it is to extract DNA from the dead and how there is a great risk of contamination. It is amazing what can be done with information on someone's DNA.

Article: http://www.popularmechanics.com/science/health/genetics/scientists-confirm-remains-king-richard-iii-17487010