BioQuakes

AP Biology class blog for discussing current research in Biology

Author: orsbio

Echinacea’s Habitat Decline

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On February 28, 2014

In Student Post

The plant that is commonly used to treat flu and cold symptoms, Echinacea, is beginning to suffer from a disappearing habitat. A flowering plant part of the daisy family, Echinacea grows in central and North America in mostly dry, wooded areas. As one of the “top five” herbal remedies sold in retail stores, the coneflower is regarded as an American staple to relieve suffers’ of the cold and flu. However, their habitat is in decline from human activities, bees, and deadly aphids

EchinaceaPurpureaMaxima1a.UME          Certain human activities have caused wildlands to shrink and splintered the landscape. As one of the most endangered habitats in the world, tailgrass prairie is throughly studied by scientists in order to track how Echinacea reacting to its changing environment and they are also working to save these prairie patches.

Bees have been known by scientists to pollinate the coneflower plant, Dr. Wagenius says “A bee might have been able to fly across a hundred mile expanse of coneflowers. Could it still do that today? No way.” Pollination for these plants is not at all where it should be, as bees can only pollinate these plants up to short distances.

Coneflower plants are now becoming genetically related in the prairies. If a bee brings pollen to these different plant siblings, the plant may reject the pollen. Therefore, there are no new seeds and populations decrease. A new danger to the coneflower is aphids; they devour prairies of Echinacea. As well, scientists urge prairie farmers to set fire to habitats (since they are necessary to these ecosystems). By inducing the plant to flower, new genetic diversity may be reached.

The “Social” Bacteria

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On January 19, 2014

In Student Post

800px-M._xanthus_development        The Myxococcus xanthus is a bacterium found in soil that scientist identify as a “social” bacteria. Organized into multi-cellular and three-dimensional structures made of thousands of cells, the bacterium works together by hunting for food and surviving under difficult conditions. They form interesting structures and help each other survive, which are fascinating points of study for scientists who have been researching E. Coli (which has medical significance and influence) in test tubes. However scientists believe that this behavior in test tubes is obviously not as revealing as bacteria behavior in a social or spacial structure that they find in Myxococcus xanthus.

       Myxococcus xanthus eats other microbes and is therefore classified as “predatory”. The structural complex that the thousands of cells form interests scientists, because it is self-made and because it can hunt, kill, and digest various different microbes. By identifying the mechanisms that help the bacteria achieve their multi-cellular behaviors, scientists believe that this will answer questions about how individual cells break their symmetry to organize into these complicated many-celled compositions, teaching scientists about the evolution of multi-cellularity. “The most primitive form of life is single-cell life,” Igoshin, a scientific investigator, says. “The next step up would be going from single cells to multicellular organisms. These bacteria are somewhat in the middle.”

      The bacterium is capable of adopting various forms (ripples, segments, fruiting bodies) in order to hunt for food successfully as a unit and live for a long time together. These capabilities give researchers insight into designing future antibiotics by understanding its functions and methods, especially in embryonic development and other manifestations of this kind. 

Tasmanian Devil Extinction on the Horizon

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On November 19, 2013

In Student Post

The tasmanian devil is most readily remembered by it’s cartoon character, however the extinction of the animal seems to be on the horizon. Tasmanian devils are wild animals of the Dasyuridae family found only in the wild of Australian island of Tasmania. Recently, it has been predicted that a facial cancer on the marsupial will extinct the species in the next ten years.

First reported in 1996, the parasitic tumor has declined the species by seventy percent. The onset of the non-viral tumor was caused by the environment of the animal (who live in high-density populations that suffer from invasions of nonnative species and pollution.) Devil facial tumor disease likely began in what are called Schwann cells. Schwann cells are found in the peripheral nervous system; they produce myelin and other proteins essential for the functions of nerve cells.

Scientists are trying to remedy the infectious disease by breeding a certain species of tasmanian devil that was shown to have a partial immunity to the tumor. After preliminary research on the disease, scientists have come to see that the answers to the tasmanian devil’s circumstance, if uncovered, could lead to answers for human cancers as well. More knowledge of the direction and rate of the tumor in devil populations will help scientists to find out more about how the disease spreads byYoung_tasmanian_devil examining the interactions between the animals. Scientists remain positive; Andrew Storfer, who works closely with the animals on location, says “the answers will help in developing responses to this and other disease outbreaks in Tasmanian devils–and potentially in people.”

Dr. Light

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On November 18, 2013

In Student Post

Cardiac arrhythmia is a problem with the rate of heart beat that currently affects 4 million Americans. During arrhythmia, the heart may beat too fast, too slow, or have an obvious irregular rhythm. In some cases, this heart condition may be life-threatening with the ability to damage the brain, heart, and other organs due to the lack of blood flow.

Oscar Abilez, a cardiovascular physician at Stanford University has developed the solution to this condition: light. With his team, he is working to create a new biological pacemaker that is able to control the heart with light. The first phase of his research involves optogenetics. This uses techniques from both optics and genetics to control the activity of individual neurons in living tissue. In 2002, German scientists were able to isolate the genes for the proteins called opsins. Before this discovery, algae and few other organisms were the only know carriers of light sensitive cells. These opsins, however, are responsible for cells’ light sensitivity in humans and modify the genetic code of other cells so that they, too, would produce these opsins. 

The next phase of his research involves stem cells. Oscar Abilez hopes to convert the stem cells light-sensitive cardiomyocytes from a person who is suffering from this condition.  These cells that make up the muscle tissue in the heart  would be able to be “grafted” onto a person’s heart. This would then ideally carry out Abilez’s vision, which he hopes will be achieved in the next decade or so, allowing physicians to control the whole heart’s rhythm using light.VPC_1

Hearing Loss Clue Uncovered

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On September 29, 2013

In Student Post

In the United States, approximately forty-eight million (twenty percent) of men and women suffer some degree of hearing loss, as it is the third most common physical condition after arthritis and heart disease. While it is most often associated with the population sixty-five and
older, hearing loss effects all ages, as thirty school children per out one-thousand are afflicted in some varying degree. An individual is able to hear sound involving the ear’s main structures. In age-related hearing loss, one or more of these structures is damaged: the external ear canal, the middle ear, and the inner ear. External ear canal impairment is related exclusively to conducive hearing loss. The middle ear, which is separated from the ear canal by the eardrum may be caused by sensorineural hearing loss. Lastly, the inner ear, which contains the cochlea, the main sensory organ of hearing. When the vibrations from the middle ear enter the cochlea it causes the fluid to move and the sensory hair cells pick up this movement. In response to the movement of the fluid the hair cells send an electrical signal up the auditory nerve to the brain where it’s recognized as sound.

 

Now, how do these different internal departments of the human ear gradually induce hearing loss? While we get older, some may develop presbycusis, which causes the tiny hair-like cells in the cochlea to deteriorate over time. Clarity of sound decreases, as the hairs are unable to vibrate as effectively in response to sound. Recently, otolaryngologists have discovered new evidence that human hearing loss relates to a certain genetic mutations. A study at the University of Melbourne revealed “a novel genetic mutation was first identified in 2010 as causing hearing loss in humans… now discovered that this mutation induces malfunction of an inhibitor of an enzyme commonly found in our body that destroys proteins – known scientifically as SERPINB6. Individuals who lacked both copies of this “good gene” were shown to have lost their hearing by twenty years of age.

 

Although this discovery is changing the way scientists previously viewed hearing loss, the answer to why this mutation, SERPINB6, is a catalysts for such loss, is inconclusive. However, this mutative gene has created a revelation for many: it is now not unusual to show gradual signs of hearing loss under the age of sixty years.

 

To better understand the effects of the mutant gene, mice were used in order to imitate the condition from youth to adulthood. At only three weeks of age, mice with SERPINB6 had begun to lose hearing – three weeks is equivalent to pubescent or teenage years in humans. And as we could have predicted, the mice continued to show a decrease in hearing ability, much the same as humans. Researchers examined the mice’s inner ear, which revealed the cells responsible for interpreting sound (sensory hair cells) had died.

 

Fortunately, this new discovery of a mutant gene in human sensory cells has created new attention to better understand the case of those who are effected by the condition. 

 

 

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