Roger Y. Tsien and the discovery of GFP (green fluorescent protein) by

Early Discovery of the Fluorescent Effect

gospodinov2 — 2024-02-22 18:48:32 UTC

Early observations of fluorescence began to be observed starting as early as 1560. Two Spanish men independently made observations of this scientific phenomenon between 1560 and 1565. Their names were Bernardino de Sahagún (a Franciscan missionary) and Nicolás Monardes (physician and botanist). They both observed the concept of fluorescence in a medicinal substance called lignum nephriticum, which is made from water and the wood from the narra and kidneywood trees. When mixed together the water would have a strange blue color. This fluorescence was recorded by both men in their writings¹.

Though this did not explicitly relate to the field of neuroscience it was foundationally for gaining a basic understanding that fluorescence exists and can be found in naturally occurring substances like plants. Eventually, this knowledge of fluorescence would prove to be an important piece of the puzzle to many scientific solutions.

Sources:

(1):https://fluorescence-foundation.org/lectures/chicago2011/lecture1.pdf

Individual Entry: Roger Y. Tsien

gospodinov2 — 2024-02-22 19:40:33 UTC

My docent is Roger Y. Tsien who was an American chemist that lived from February 1, 1952, to August 24, 2016. He began his work on the green fluorescent protein in 1994 and eventually, he and the other two recipients earned a Nobel Prize for the research they did on GFP. Their work paved the way for more in-depth research into certain biological processes. Tsien helped add more colors to be used with GFP and he found ways to make the protein stand out more and produce a brighter glow¹. This allowed for more biological processes to be studied in the brain and the rest of the body.

Tsien had an early passion for science, especially the field of chemistry. He had asthma when he was young which prevented him from spending time doing outdoor activities that caused physical exertion. As such he began to dive into the world of science from his own home. He had his own chemistry lab in the basement where he would do experiments and develop his love for the field¹.

Source:

(1):https://www.britannica.com/biography/Roger-Y-Tsien

(2):https://en.wikipedia.org/wiki/Roger_Y._Tsien

Discovery of GFP (green fluorescent protein)

gospodinov2 — 2024-02-22 20:55:21 UTC

The green fluorescent protein was discovered in the 1960s within the Aequorea victoria jellyfish by Osamu Shimomura and his team. These jellyfish naturally produce bioluminescent proteins allowing them to have a "glowing" effect. The two that they produce are aequorin and GFP. Within the light organs of these animals, calcium and the bioluminescent proteins are used to produce the characteristic glow of these jellyfish¹. They are typically found on the west coast of North America².

This discovery was incredibly important for the field of biology and neuroscience. GFP can be used to tag proteins and to observe gene expression as well as other experimental techniques used by researchers. It also allowed scientists like Roger Tsien to expand upon its uses and make it an even more effective research tool.

Source:

(1):https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037093/

(2):https://en.wikipedia.org/wiki/Aequorea_victoria#:~:text=Aequorea%20victoria%20are%20found%20along,living%20polyp%20in%20late%20spring.

Tsien's Lab Fine Tuning of GFP

gospodinov2 — 2024-02-23 12:10:09 UTC

In 1998, at the University of California, San Diego, Tsien and his team were able to make GFP more of a useful tool to the scientific community by amplifying some of its properties and making it more versatile. The first way they did this was by making a version of GFP that could appear brighter and would make it easier for researchers to visualize it under a microscope. This version was more stable and functioned much better with the typical equipment available at the time¹.

In addition to this, they were able to make GMP more versatile by increasing the amount of color from just green to blue, yellow, and others. This provided a diverse amount of ways to tag proteins when studying biological processes. Scientists were now able to track multiple proteins at once giving them a fuller and more comprehensive understanding of certain cellular processes¹. This certainly helped expand the field of neuroscience as well by creating yet another tool that could be used to study the brain and its various compositions such as neurons. Scientists were able to use GMP to tag neurons and gain a better understanding of their role in the brain.

Source:

(1):https://www.nature.com/articles/milelight18

First Use of The Term Fluorescence

gospodinov2 — 2024-02-23 13:13:11 UTC

In 1852 George Gabriel Stokes had a substantial scientific work published. Within this work, he coined the term "fluorescence" while describing a phenomenon that occurred during one of his experiments². He took a vial of quinine sulphate and used sunlight to pass the tube through the spectrum of light. At one point during the experiment, the solution turned a bluish-light color¹. As a result of this experiment, Stokes was able to give a thorough description of fluorescence in his writings. Although not all his ideas were true, he was a foundational part of setting the stage for other scientists who would use his work as the foundation for their studies.

Once again though this experiment did not directly impact the field of neuroscience, it was a necessary step in the right direction towards developing GFP which itself has made a huge impact on the field.

Source:

(1): https://www.mindat.org/article.php/4143/George+Gabriel+Stokes+and+the+phenomenon+of+fluorescence+

(2):https://www.innopsys.com/fluorescence-imaging-what-is-it/

Contemporary Entry: GFP Whole-Brain Imaging

gospodinov2 — 2024-02-23 13:33:35 UTC

GFP has been becoming an even more useful tool in recent years with its use in whole-brain imaging. This technique allows further expansion of knowledge in the cellular tissue of the brain. It can provide many different types of information such as connectivity, the number of cells in a given brain region, the arrangement of neurons, and other cellular structures¹. The usage of this technique spans a wide variety of areas of study in neuroscience.

Some of the applications for this technique can be used to characterize brain function and understand differences between various regions and divisions of the brain. There are also strong benefits of whole-brain imaging in studying various neurological diseases¹. For instance, researchers can use animal models to study what certain neurological diseases do to harm the brain. They can perform GFP whole-brain imaging on both a healthy population of animals and a diseased population. They can then compare the damage done by the disease on certain brain structures versus the healthy animals. This can help narrow down what treatments would be most effective in combating neurological disorders such as Alzheimer's disease.

Source:

(1):https://www.frontiersin.org/articles/10.3389/fnmol.2022.958222/full

Cloning of GFP Gene

gospodinov2 — 2024-02-23 15:19:12 UTC

In 1992 GFP was finally cloned and its genetic sequence was identified by Douglas Prasher and his team. This was done about 30 years after the protein was initially observed in the Aequorea victoria jellyfish. This was a very important step in making GFP a common scientific technique. Without the cloning of GFP then Roger Y. Tsien and others would not have been able to advance the field because they would have been able to experiment with the protein and provide ways to make it more useful¹.

At this point, GFP was in its infancy and was not yet being used to advance the field of neuroscience, but this was certainly an important step in getting to the point where it would be useful.

Source:

(1):https://www.sciencedirect.com/science/article/pii/037811199290691H?via%3Dihub

Fluorescent Microscopy

gospodinov2 — 2024-02-23 19:40:47 UTC

One of the most necessary components to using GFP is the microscope needed to visualize the protein properly. Without the fluorescent microscope, GFP would not be as useful of a tool for researching biological and neurological processes.

The first one of these fluorescent microscopes was invented by Otto Heimstaedt and Heinrich Lehman who were both from Germany. These physicists came up with the first version between 1911 and 1913. They used the concept behind ultraviolet microscopes and adjusted them to fit the necessary requirements to visualize fluorscence¹. This allowed scientists to dye fixed and living cells in order to study them and their function in various organisms. Eventually, this technique began to be used in the field of neuroscience which was especially beneficial to visualizing neurons and other cellular structures in the brain.

Source:

(1):https://zeiss-campus.magnet.fsu.edu/articles/basics/fluorescence.html#:~:text=The%20first%20fluorescence%20microscopes%20were,off%20from%20the%20ultraviolet%20instrument.

Adding GFP Gene to Other Organisms

gospodinov2 — 2024-02-23 20:03:22 UTC

Martin Chalfie was one of the other three people along with Roger Tsien that shared the Nobel Prize in 2008. In 1993 Chalfie and his lab proved that the gene for GFP could be placed within the genetic sequence of other organisms. These organisms would then go on to produce their own GFP. The organisms that they originally proved this on were E. coli and C. elegans¹.

This finding essentially made it known that GFP could be used on any organism to learn more about its biology¹. Specifically for the field of neuroscience, this opened up the door to using GFP on mice and rats which are common test subjects when researching the brain.

Source:

(1):https://www.britannica.com/biography/Martin-Chalfie

Oxygen Requirements of GFP

gospodinov2 — 2024-02-23 20:53:43 UTC

In 1994 Roger Tsien and his team determined that in order for GFP to function in an organism, oxygen must be present¹. That means that certain organisms like anaerobic bacteria cannot produce GFP even when it is inserted into their genetic sequence. This is one of the limitations of GFP but it has still proven itself to be a versatile and highly capable tool in regards to research in the field of biology and neuroscience.

This minor drawback to GFP has not been an issue in the field of neuroscience. Most model organisms used for neuroscience research typically use oxygen, such as rodents and primates. Therefore it has not hindered that area of research.

Source:

(1):https://www.britannica.com/biography/Roger-Y-Tsien

Observation of Fluorescence in Nature

gospodinov2 — 2024-02-23 22:11:36 UTC

People have noticed and observed fluorescence in organisms for thousands of years. One of these early observations was by Gaius Plinus Secundus or "Pliny the Elder". He lived from 23 A.D.-79 A.D. and was a philosopher by trade focusing much of his interests on the natural world around him¹.

He was able to observe fluorescence when he was in the Mediterranean Sea. There he spotted jellyfish rolling with the waves that emitted light from their tissues. He was so awestruck by the light that he described its strength as that of a "torch"¹.

Though Gaius only made surface-level observations during his time in the Mediterranean his curiosity shows the early desire in people to understand this amazing natural phenomena. Eventually, this curiosity would lead to leaps and bounds in the field of neuroscience.

Source:

(1):https://www.leica-microsystems.com/science-lab/life-science/fluorescent-proteins-from-the-beginnings-to-the-nobel-prize/

Additional Fluorescent Protein Discoveries

gospodinov2 — 2024-02-23 22:28:34 UTC

At the turn of the 21st centurty Sergey A. Lukyanov made further strides in the field of fluorescent proteins. Of all the places he could have discovered this new finding it ended up being in a pet shop in Moscow, Russia.

Sergey is a Russian biochemist who provided an even further expansion of the fluorescent protein colors that were available to scientists. He discovered a red fluorescing protein in coral that was being sold to people who kept aquariums as a hobby. Sergey and his fellow coworkers were able to experiment with these corals and identify several new colors that could be used for research including a wide range of red¹.

This was yet another step in making GFP a well-rounded scientific tool that could be used for a variety of purposes. Adding even more colors allowed neuroscientists to study complicated brain processes that involve numerous working cellular parts.

Sources:

(1):https://www.leica-microsystems.com/science-lab/life-science/fluorescent-proteins-from-the-beginnings-to-the-nobel-prize/