replication – BioQuakes

Cracking the Code one Gene at a Time

On October 26, 2019

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.”

Process of RNA Transcription

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.

Fluorescent Image of Living Cells

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.

i-motif: A new form of DNA discovered

By paxian

On May 1, 2018

In Student Post

Australian researchers have discovered a new structure of DNA called i-motif. This form of DNA is in the shape of a twisted knot, vastly different from the conventional double helix model. i-motif basically looks like a four-stranded knot of DNA. In the i-motif form, the C bases on the same strand of DNA bind to each other instead of their complementary pairs.

(Photo: Wikimedia Commons)

How did scientists discover i-motif?

i-motif previously haven’t been seen before, apart from in in-vitro (which means under laboratory conditions and not in the natural world) To detect i-motif, scientists used a tool made up of a fragment of an antibody molecule. This antibody could recognize and attach to i-motifs. Researchers showed that the i-motif structures mostly formed at the G1 phase -when mRNA is synthesized- in a cells life cycle. The i-motifs show up in promoter regions and in telomeres in the chromosome.

While scientists aren’t really sure the actual reason for their existence, some researchers suggest that they are there to help switch genes on and off and affect whether or not a gene is actively read.

Whatever the reason for their existence, they have potential to play an important role in how and when DNA is read. Prof Marcel Dinger at the Garvan Institute for Medical Research says, “It’s exciting to uncover a whole new form of DNA in cells — and these findings will set the stage for a whole new push to understand what this new DNA shape is really for, and whether it will impact on health and disease.”

Protein Might Help Fight Deadly Diseases

By leahna

On March 10, 2013

In Student Post

The enzyme “Cholesterol-25-Hydroxylase,” or CH25H, might help fight against human viruses such as Rift Valley Fever, Niphah and HIV. CH25H converts cholesterol to an oxysterol called 25HC, which can permeate a cell’s wall to prevent a virus from getting in. The CH25H enzyme is activated by interferon, an anti-viral cell signaling protein produced in the body. Researchers have known that interferon has been part of the body’s defense mechanism against viruses, though it does not have any antiviral properties itself.

This discovery is revolutionary because other antiviral genes have not been able to be used for treatment of viruses in humans. According to Yang Lui, a student at the David Geffen School of Medicine at UCLA, most antiviral genes are difficult to use in therapy because the genes are difficult for cells to express. However, CH25H is different because it is naturally synthesized.

HIV Replication within a cell

The discovery of CH25H is relevant to the efforts to develop broad antivirals against an increase of emerging pathogens. In a collaboration with Dr. Lee, another UCLA professor, it was discovered that the 25HC produced from CH25H can inhibit HIV growth in vivo. The researchers initially found that 25HC inhibited HIV growth in cultures. When implanted mice with human tissues, the 25HC reduced the HIV in within 7 days and reversed T-Cell depletion caused by the HIV. It was also discovered that 25HC inhibited the growth of other diseases such as Rift Valley Fever Virus and Ebola.

There are still some weaknesses with the study. It’s difficult to deliver 25HC in the large doses needed to fight viruses. Researchers also need to compare 25HC to other antiviral HIV treatments.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: replication

Cracking the Code one Gene at a Time

i-motif: A new form of DNA discovered

Protein Might Help Fight Deadly Diseases

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