The Resilient Water Bear Reveals its Genetic Secrets

water bear

The water bear can survive extreme conditions–and its foreign DNA may explain why. (Photo credit: Eye of Science/Science Source)

Though cute, at less than a millimeter in length, water bears aren’t exactly what you might call cuddly. Water bears are known for their ability to survive extreme conditions ranging from the depths of the oceans to the soaring heights of the Himalayas. Recent research indicates these tiny creatures have another unusual trait – nearly 20 percent of their DNA comes from other species. [Read more…]

Spider Goat, Spider Goat . . . Her Milk Could Make a Bulletproof Coat

spider

Scientists inserted the silk-making gene from a golden orb spider, such as the one shown here, into a goat to produce goat’s milk that contains spider silk. (Photo credit: Christopher Meder/Getty Images)

Genetic engineering is nothing new. In fact, it’s a practice that’s literally thousands of years old. For centuries, humans have selectively bred plants and animals in an attempt to pass along desired traits. Today, however, genetic engineering has taken the practice to a new level.

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Researchers Use DNA Barcodes to Investigate Fern Identify

Plant nurseries may unknowingly be selling plants that are not what they say they are. (Credit: Emilio Ereza/Alamy)

In the past, scientists used morphological clues to help identify and distinguish between different species. Now, with just a little bit of tissue, researchers can use a new tool called DNA barcoding to identify different species and determine the relationships between them.

Mystery Ferns

Recently, researchers in North Carolina used DNA barcoding to identify a species of fern plant being sold in a local plant nursery. The scientists were not convinced that the plant was labeled correctly. With the help of DNA barcoding, the scientists were able to determine that the ferns being marketed as Wrights Lip ferns (Cheilanthes wrightii), a species native to the southwestern United States and northern Mexico, were actually bristle cloak ferns (Cheilanthes distans), a species native to Australia and some islands in the South Pacific.

Ferns are particularly hard to identify due to a lack of fruits or flowers. Misidentifications can easily occur in a greenhouse setting, either intentionally or accidentally. Because most nurseries do not employ taxonomists, these mistakes often go by unnoticed. So whats the big deal? One problem lies in mistaking non-native plants for a native species. When this happens, there is a potential for introducing invasive species, or unknowingly selling endangered species.

DNA Barcoding

DNA barcoding is a relatively-new technique that was developed by scientists at the University of Guelph (located in Ontario, Canada) in 2003. According to the Consortium for the Barcode of Life, this technique uses a short DNA sequence from a standardized location in the genome as a way to identify a species using molecular data. Many liken this technique to the use of a barcode, or UPC label, on a product in a store. Though two items may look similar, each has a unique UPC code that is distinguished by a scanner that can read the code to identify the product. Similarly, a specific DNA sequence in a gene can be read to identify a species with the use of DNA barcoding.

Initially, the technique was applicable to animal species only. However, in 2008, scientists in the Department of Life Sciences at London’s Imperial College found that a DNA sequence in the gene called matK is nearly identical in plants of the same species, though it differs among plants of different species. Scientists can use this DNA sequence to identify plant species and determine relationships among them. This technique is especially helpful in either confirming or refuting relationships among species. For example, while identifying orchid species in Costa Rica using this technique, scientists determined that what was considered to be a single species of orchid was in fact two separate species.

Future Uses

According to one of the researchers involved in the North Carolina study, DNA barcoding could be used to prevent the sale of harmful, rare, or endangered plant species. It could also aid customs officers work in stopping the sale or trade of these species. The technique of DNA barcoding makes this scenario particularly possible because only a small amount of plant or animal material is necessary to identify a species, rather than the whole organism. In addition, several scientists imagine a scenario where researchers will be able to use a Star Trek-like transponder to easily identify one species from another. Though this molecular technique is still in its infancy, scientists are excited by the possibilities that DNA barcoding may have in the future.

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Astronaut Food Approach to Medical Testing

What comes to your mind when you think of astronaut food? You might think of food that is dried-out and nonperishable. These same descriptions might soon be applied to new malaria tests that do not require refrigeration and are small enough to fit in a wallet. These malaria tests were recently developed by researchers at the University of Washington.

How do the malaria tests work? Each test is a small piece of plastic about the size of a credit card. When a sick persons blood sample is added to the card, the blood mixes with dried antibodies. The antibodies turn colors if the blood sample is positive for malarial proteins. In the future, the University of Washington researchers are hoping to develop tests for other diseases, such as the flu and measles. In addition, they hope to test for DNA and RNA of the viruses and bacteria that cause these diseases so that doctors can be absolutely certain which disease the patient has.

Its very likely that your doctor will never use the astronaut-style tests on you, because these tests are being developed for use in poor, rural areas, like those in third world countries. In these areas, patients do not have access to medical care on a regular basis, and the medical professionals that are around may not have access to medical labs. The tests being developed at the University of Washington do not require complicated set-ups and can be used quickly to diagnose patients. These tests are important new developments in the worldwide fight against deadly diseases.

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Cold Symptoms Linked to Immune Response, Not Cold Virus

Currently, there is not a cure for the common cold. When you catch a cold, doctors often advise that you drink a lot of fluids and maybe even have a bowl or two of chicken soup. You could take some cold medication, but these just work to mask the symptoms rather than cure the problem. However, recent research may change the way the common cold is dealt within fact, it may even lead to a cure.

The research, published in the November issue of American Journal of Respiratory and Critical Care Medicine, indicates that cold symptoms, such as coughing, sneezing, and a runny nose, are not caused by the human rhinovirus (HRV). (HRV is responsible for 30-50 percent of all common cold cases.) Instead, these symptoms result from the immune system response. The study was led by David Proud, a professor in the department of physiology and biophysics at the University of Calgary in Canada. In conducting his research, Proud collaborated with scientists at the University of Virginia and Procter & Gamble Company.

In the study, 35 volunteers were injected with either HRV or a harmless substance. Skin scrapings from the inside of each volunteer’s nose were taken both before and after infection. Researchers at Procter & Gamble used gene chip technology to analyze whether any genetic changes took place after infection. Gene chip technology lets scientists see every gene in the human genome–allowing scientists to see how genes respond to a stimulus, such as the introduction of a cold virus.

The researchers did not detect any changes to the test subjects’ DNA after a period of 8 hours. However, after a period of 48 hours, scientists discovered that over 6500 genes had been altered. The affected genes showed either an increased or decreased amount of activity. The genes that were most affected were those that make antiviral proteins and pro-inflammatory chemicals. This finding shows that antiviral proteins work to thwart the rhinovirus, but also produce the symptoms associated with a cold.

Results from this research may help scientists develop an effective cure for the common cold. If they can identify the pro-inflammatory genes, they could develop methods to block the genes’ function. However, researchers are hoping to find more than just a cure for the common cold. The pathogen responsible for the rhinovirus has also been implicated in more serious health conditions such as asthma and chronic obstructive pulmonary disease (COPD). By learning how to combat the rhinovirus, researchers may also be able to find a way to cure these conditions as well.

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