AP Biology class blog for discussing current research in Biology

Tag: new

Discovering and Using Your Personal, Biological, Tiny Army

Bacteria is an important part of our biology, so important that we are essentially 99% bacteria. A lot of this bacteria is part of the human gut microbiome. This topic has been picking up interest in the field of biology, and have shown linkage to many diseases such as inflammatory bowel disease and obesity. Not only do the bacteria in our gut play a role in preventing these diseases, but their symbiotic relationship helps us maintain metabolic functions.

File:The first and second phases of the NIH Human Microbiome Project.png

This is a depiction of the numerous types of bacteria in our microbiome.

Until recently we were unable to study these bacteria due to our inability to cultivate them in a lab; however, due to new advancements in sequencing technology we can now see how big of  role they play in our biology and our functions. These bacteria are “estimated to harbor 50- to 100-fold more genes, compared to the hose. These extra genes have added various type of enzymatic proteins which were non-encoded by the host, and play a critical role in facilitating host metabolism.” For example, gut microbiata is very important in fermenting unabsorbed starches. These bacteria also aid in the production of ATP. A certain type of bacteria generates about 70% of ATP for the colon with a substance called butyrate as the fuel.

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This image shows the interaction between the gut and the immune system. The immune system targets bacteria, but somehow not our gut bacteria. 

Another large role of the gut microbiome is its interactions with out immune system and nervous system. The bacteria in our gut suppress the inflammatory response in order to not be targeted by the immune system. This allows for a symbiotic relationship between us and the bacteria inside of us. This allows the gut bacteria to help regulate the inflammatory response without being stopped by the very thing it’s regulating. Without these bacteria our inflammatory responses would be completely out of the ordinary.

These findings with gut bacteria are fairly new and there is much more to come regarding their use in the field of medicine. Something to think about that I found fun was how little of us is really human. Ninety nine percent of you is bacteria, which essentially means that we are pretty much just giant colonies of bacteria. Kind of gross/amazing when you think about it.

Cracking the Code one Gene at a Time

Cells are one of the most important objects in the human body, yet scientists still have yet to truly understand the underlying mechanics. Recently researchers have observed how RNA transcription occurs in real, live cells. For the longest time scientists have observed RNA transcription extracellularly. Until now they have only been able to observe how RNA polymerase 2, a DNA copying enzyme, and other enzymes “by breaking cells apart and measuring the activity… outside the cellular environment.”


The molecules involved in RNA transcription have been studied profusely, but only frozen in time. Now we can use “a highly specialized optical microscope” to watch how RNA polymerase copies DNA into mRNA. Researchers then labeled certain molecules with a tag so that they glowed when looked at. An issue with this method, though, is that there are so many of these molecules in the nucleus that if we were just to examine the reactions after adding the fluorescent tag, we would just have a glowing nucleus. The scientists have combated this by suppressing the signals from other reactions. This, along with the ultra-sensitive microscope allows us to focus on one gene and transcription occurs for it.

Through this new technique, we now have a much more detailed and intricate picture of how DNA, RNA, and enzymes function in transcription. This process can be replicated for many more reactions and will help us understand bounds more about ourselves and how we truly work.

I am personally very excited to see what new concepts and techniques will be discovered from this breakthrough. Genetics is the future of biology and using this to crack the code is one step closer to curing many genetic diseases. Combining this with other genetic breakthroughs like CRISPR is a cause for excitement in the future of biology. If you have any other ideas about why this could be useful please comment below.


Dr. Light

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

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